Pure,White And Deadly
By John Yudkin
Much of the experimental work that I shall cite here was carried out in the Department of Nutrition atQueenElizabethCollege.I have been most fortunate in having had,over several years,many colleagues and research students who have contributed greatly to the ideas and to the hard work involved in the slow-the enormously slow-unravelling of some of the problems that we have tackled.
Without their collaboration many of the facts I quote would not have been known.Finally,I must say here how grateful I am to the many firms in the food and pharmaceutical industry that for25years have given me such constant generous support in the building up and maintenance of the Department of Nutrition.For many of them,the results of our research were often not at all in their interests,yet it was largely with their help that we were able to work on those problems that,to me,seemed of such importance.
A great deal has been written about sugar.There are dozens of books about the cultivation of the sugar cane and the sugar beet,including books that describe the shameful story of the slave trade between Europe,West Africa and theCaribbean.There are dozens of books giving the technical details of sugar refining and the manufacture of sugar-containing food and drinks.But further accurate information about sugar as a food is not easy to come by.How many people eat more than average and how many eat less?Who are the small consumers and who are the big consumers and what are the smallest and largest amounts consumed?What would it do to our health if we took no sugar at all,or if we ate quite large amounts?Part of this information can,with some trouble,be found in trade publications,but not all of it.You might think you could get it from the sugar industry itself;they undoubtedly have active information centres in many countries.We know what the average sugar consumption is in each country.But it is not possible to get the answer even to such simple questions as how much sugar is in the diets of people of different ages,or what is the range of the sugar content of the diet of I5-year-old British schoolchildren.It may be that their industry simply does not have this information,or it may be that they have it but do not wish it to be known.Especially,we would expect the sugar industry to be knowledgeable about levels of consumption when,in rejecting criticisms of the effects on health,they constantly refer to "moderate"consumption.Yet what the industry considers moderate must,on any reckoning,be quite a sizeable quantity.One of the scientists who most strongly supports the sugar industry has written, "The usual range of sugar intake may therefore be between10and30per cent of total calories,with the average at15to20per cent.”He goes on to say, "This rate of sugar intake may be considered moderate,and can probably be exceeded somewhat without overstepping the balance of moderation."Much more research has been done on the effects on health of the bread in our diet,or the eggs,or the breakfast cereals,or the meat,or the vegetables,than about the effects of sugar,even though sugar on average constitutes about17per cent of our diet,a larger proportion than any of these other items.Yet in1972,when Pure,White and Deadly was first published,what little research there had been already showed that sugar in our diet might be involved in the productionof several conditions,including not only tooth decay and overweight but also diabetes and heartdisease.Since that time research has produced further evidence that sugar is implicated in these conditions,and has also added to the list of diseases in which the sugar we eat may possibly,or evenprobably,be a factor.Many of the experiments from which these conclusions are derived have been carried out at the Nutrition Department of QueenElizabethCollege,University ofLondon,some of them in collaboration with research workers in the Biochemistry Department.When our experiments have been repeated independently in other research institutes,the results have always been in line with our own.Those who disagree with what we say may therefore challenge the conclusions that we draw from the research,but they cannot legitimately disagree with the experimental results.In this edition I have taken the opportunity to bring up to date and extend many of the statistics that I quoted earlier.I have also summarized the research that we and others have done during the last14or15years which has shown more of what happens in our bodies when we eatsugar.I am often asked why we don't hear very much about the dangers of sugar,while we are constantly being told we have too much fat in our diet,and not enough fibre.I suggest that you will find at least part of the answer in the last chapter of this book.
.What’s so different About sugar?
Sugar is common enough in all our lives,and almost everyone believes that it is simply an attractive sweet-one of many carbohydrates in the diet of civilized countries.But sugar is really quite an extraordinary substance.It is unique in the plant that makes it,in the materials that chemists can produce fromit,and in its use in foods at home and in industry.And recent research shows that it also has unique effects in the body,different from those of other carbohydrates.Since it now amounts to about one sixth of the total calories consumed in the wealthier countries,it is essential that more is known about what it does to people when it enters the body in food anddrink.Curiously enough,not only the layman but also the physician and the medical research worker have until recently assumed that there was no need to bother with any special study of sugar.Since man began to produce his food instead of hunting and gathering it,his diet has contained large amounts of carbohydrates of one sort or another (see p.10).It did not seem to occur to anyone that it made any difference whether this carbohydrate consisted almost entirely of starch in wheat or rice or maize,or whether the starch was gradually becoming replaced by increasing amounts of sugar,as has been happening in the last100or200years.Although some early research workers occasionally pointed out that eating sugar was not always the same as eating starch,no one paid much attention to this until25years or so ago.When I wrote a book on weight reduction in1958,I strongly recommended a diet low in carbohydrate,but I made very little distinction between the benefits of avoiding starch and avoiding sugar.Since that time,an enormous amount of new information has been accumulating,and more is being added constantly.Most of the new research has,quiteproperly,appeared in scientific and medical journals,but it seems now worth while to summarize it for non-technical people.After all,it is not only scientists and physicians who eat,and if eatingsugar really is dangerous,then everyone should be told about it.The fact that so much about the effects of sugar is still being discovered is in itself an illustration of how unexpected it was to find so many differences in these effects from those of other common foods.You might have imagined that the realization that there were differences would have stimulated the sugar producers and refiners themselves to initiate studies into the properties of their product.Other industries which produce foods like meat or dairy products or fruits have spent a great deal of money over the years to carry out or support nutritional studies on their products,even though these foods form a smaller proportion of the western diet than sugar now does.But the sugar people seem quite content to spend their money on advertising and public relations,making claims about quick energy and-as we shall see later-simply rejecting suggestions that sugar is really harmful to the heart or the teeth or the figure or to health ingeneral.I cannot claim that everything I say in this book will be accepted by every research worker.I hope however that I have made it clear which parts of the book refer to solid,observable scientific research and which parts are my own opinions and interpretations of these observations.Only time will show how right or how wrong I am in any one particular personal statement.But right at the outset I can make two key statements that no one can refute:First,there is no physiological requirement for sugar;all human nutritional needs can be met in full without having to take a single spoon of white or brown or raw sugar,on its own or in any food or drink.
Secondly,if only a small fraction of what is already known about the effects of sugar were to be revealed in relation to any other material used as a food additive,that material would promptly bebanned.
Take the case of cyclamates.Some countries now do not permit this sugar substitute to be used,and the prohibition is based on experiments in which rats were fed for an enormously long time on huge amounts of cyclamate-the equivalent of a man consuming10to12pounds of sugar every day for40or50years.Later in these pages you can read what can happen to rats fed sugar in amounts hardly-if at all-different from those consumed by very many people.I will not anticipate the details that you will find,but the very many effects include enlarged and fatty livers,enlarged kidneys and a shortening oflifespan.Think of all this the next time you read of an experiment that suggests that another sugar substitute may be harmful,as happened when aspartame was introduced.Note the blaze of publicity encouraged by the busy men and women who run such organizations as Sugar Information Incorporated or the Sugar Bureau.Then think of what is already known that sugar can do,as distinct from what the substitute might possibly do if taken in enormously unrealistic amounts for a long enough time.My own view is that it is perfectly safe to use these sweeteners whenever you wish to,although (for what I consider quite inadequate reasons)you cannot find cyclamate in some countries.But although they are quite safe,some people think it a good idea not to use sweeteners.They prefer to get into the habit of having less sweetness in their foods and drinks,by avoiding those foods that must be made withsugar.Many people have criticized what I have previously written;they say that the experiments that we and others have carried out have used absurdly high amounts of sugar to produce the effects we describe.One such person is the American physiologist Dr Ancel Keys,the most important and certainly the most dogmatic research worker who expounds the view that coronary disease comes from dietary fat and that sugar has nothing whatever to do with it.He Has written that "the level of sugar in the experimental diets are of the order of three or more times that in any natural diet.This is quite untrue,as we shall see,but it comes about because very few people have bothered to find out how much sugar people do,in fact,consume.You hear stories that the Turks take a very great deal of sugar,as you can see from the amounts they put into their coffee.But the Turks even now only take about one half of the amount consumed inBritain and theUnited States,and20years ago the Turks took less than one quarter.Apart from these sorts of questions,you can also go wrong when you look at official statistics without reading the small print.There have been regular annual reports of the British.diet for the last40years,and the figures given for sugar now amount to an average of about32pounds a year.But if you look carefully,you will see that the statistics do not include snacks or food eaten away from home,and the real average turns out to be more thanthree times as much,about100pounds of sugar a year.IT you now take into account that this is an average,and that many people take much more sugar than the average,you will find that the quantities used in experiments with human beings and animals are by no means extraordinary orabsurd.And what about Dr Key's reference to the sugar content "in any natural diet?What is a natural diet?Is it "natural for Westerners Today to eat20times as much sugar,or more,compared with what our ancestors ate only two or three hundred years ago,and vastly more than our earlier ancestors had ever eaten?Nowadays we hear so often the words "natural"and "moderate";we really must be on our guard not to be misled into believing that they have any real meaning,or even worse that they provide evidence that something to which these words are applied is intrinsically wholesome,good anddesirable.I hope that when you have read this book I shall have convinced you that sugar is really dangerous.At the very least,I hope I shall have persuaded you that it might be dangerous.Now add to this the fact-the indubitable fact-that neither you nor your children need to take any sugar at all,or foods or drinks made with it,in order to enjoy a completely healthy and highly nutritious diet.If as a result you now give up all or most of your sugar eating-and I shall show you later that this is not too difficult-I shall not have wasted my time in writing this book,and more importantly you will not have wasted your time in reading it.
2Ieat it because I like it
One of the most spectacular current "growth industries"is that concerned with the production and distribution of health foods.InBritain and theUnited States almost every neighbourhood has its special store where you can,it seems,ensure eternal youth by buying hand-woven honey,free-range carrots and stone groundeggs.There is no doubt that people today are very worried about their food.But different people are worried about different things,and most of them are worried about the wrong things.I can assure you that it really does not matter to your health whether your chicken-is produced by the broiler system,or whether you eat potatoes grown with chemical fertilizers.But it does matter that your diet is now very likely to be different from that which has been evolved over millions of years as the diet most suitable for you as a member of the species Homosapiens.Please don't take these sentences to imply that I have discovered the secrets of the ideal diet.Because I have written rather teasingly about "natural foods,I do not mean to imply that everything you see in the health-food store is nonsense and that everything I shall be telling you is an absolute certainty.It is true though that every person tends to believe that a knowledge of nutrition is somehow instinctive and that careful thought and introspection will provide as good an answer to nutritional questions as do the studies and research of the professionalnutritionist.It is silly to insist,in spite of all the detailed evidence to the contrary,that there are any differences in the nutritional value of potatoes produced on land fertilized by chemical fertilizers or by compost.On the other hand,it is equally silly of some scientists to imagine that we know all there is to know about humannutrition.There is,for example,no justification for the statement I heard at a scientific meeting,where a food chemist said that scientists don't have to concern themselves too much about producing enough high-protein foods;human beings will soon be able to feed themselves entirely with synthetic protein and other nutrients.And this at a time when new facts are discovered almost daily about such supposedly well-understood phenomena as obesity,or about the effects of different dietary carbohydrates.The safest position is somewhere between arrogance based on unrecognized ignorance,and arrogance based on unwarrantedcertainty.But how do we find this position?What sorts of principles do we adopt in order to decide whether this or that food is "good for you?What indeed should the ideal dietbe?I am going to devote the rest of this chapter to trying to answer these questions,slowly and carefully,because I believe that an understanding of the biology of the diet provides the clues to what the western diet should be;what is wrong with it today;and why it has gonewrong.We begin by reminding ourselves that all animals require two sorts of materials for their growth and survival.One is material that can be burned (oxidized)to yield the energy needed for the processes of living-growth and movement and breathing,and all the other activities that distinguish a living animal from a dead one.These Materials for energy production are mainly carbohydrates andfats,although protein can also be used in this way.The second sort of material consists of those thousands of different compounds that go to make up the very complex chemical composition of the cells of the different tissues that,organized together,constitute the whole living animal.The vast majority of these compounds can be made by the body itself,from a very much smaller number of raw materials.But these are all materials that must,each one ofthem,be supplied to the body.Without them,a young organism cannot grow,and an adult organism will gradually waste away because it is unable to make good the general wear and tear of its cells and tissues.So we can say at this point that the body has to be given materials both to supply energy and to provide the "raw materials for growth and repair.The source of these essential materials is our food and drink.These have to supply about50different items.They fall into several classes-the carbohydrates,the fats,the proteins,the vitamins,the mineral elements-and of course water.As far as we know,every single species of animal needs the same components for life and sustenance.And almost every single species has to get all of these out of food.The exceptions areinteresting,and include ruminants like cows which can get many vitamins from6microbes living in their complicated stomachs.But in general,as I Said,most animals have to get all of their vitamins,protein and soon from their food,and these nutrients are needed in roughly the same proportions by all animalspecies.You could therefore argue that all species of animals should eat the same foods.But in fact it is well known that different species.eat very different diets indeed.Some,like the lion and the tiger,are largely carnivorous-meat-eating.Others,like rabbits and giraffes and deer,are largely herbivorous-plant-eating or vegetarian.Others again,like ourselves and rats and pigs,eat diets that come from both animal and plant sources;these animals are omnivorous.By contrast some animals eat only a very limited range of foods;the giraffe eats little except leaves from acacia trees.The koala bear eats little except eucalyptus leaves,and then only from a few of the400or so existingspecies.So there is an apparent contradiction.First,all species of animals require the same in the way of nutrients,which-with a few exceptions-they must get from their food.But secondly,different species of animals get these same nutrients from very different sorts of diet.Great biological advantages flow from this,because it prevents the various species competing with each other for the same foods.Each Species establishes its own "ecological niche”in regard to its food supply.Its anatomy and physiology are well adapted tofind,acquire,eat,chew and digest the foods that it chooses.But the fact remains that one species will often not even attempt to eat foods that are highly sought after by another species.So what makes one animal choose one sort of diet,and a different animal choose a completely different sort?Clearly,it cannot be that they are choosing these different foods for the nutrients theycontain,since their nutrient needs are so similar.It must therefore be some other properties of foods that make one range of foods look specially attractive to one species,and another range especially attractive to another.These qualities are shape and size,colour and smell,taste and texture-features that I'd like to lump together,perhaps too loosely,under the heading of palatability.Foods thus possess two different properties-palatability and nutritional value.The palatability of foods,and so the foods chosen to make up the total diet,varies from species to species;however,the nutritional needs that have tp be satisfied by these various species are virtually the same for all species.Thus,animals choose diets that they find palatable,but,whatever these diets are,they most supply all their nutritional needs.If they did not,the animals would perish.So we can say that when an animal eats what it wants,it gets what it needs;or,in terms I have just been using,for each sort of animal palatability is a guide to nutritional value.Everyone instinctively feels that this is correct;if you like some food very much it is taken to indicate-to prove,almost-that you need this food.Eating habits are formed in childhood,and children like sweet foods.Does it follow that sugar must be good for them?Not atall,although I am sure that most people have heard this sort of argument.One also hears phrases like the one in the old music hallsong,”A little of what you fancy does you good.And so long as human beings did not manufacture foods,this argument was perfectly sound.
2.1The origin of the human diet
I shall come back later to the question of when it is true that what you want is what you need,and when it is not true.Let me now pick up the story of palatability and nutritionalvalue,and see how it applies to our own species.Science is gradually learning quite a lot about our origins,and although there are still a lot of uncertainties about the early human diet,one can now make some pretty good guesses.It is generally agreed that our earliest ancestors,the squirrel like primates of some70million years ago,were vegetarian.Theycontinued as vegetarians up to about20million years ago,for they had no difficulty in surviving on fruits,nuts,berries and leaves.But then the rainfall began to decrease and the earth entered a12-million-year period of drought.The forests shrank and their place was taken by ever-increasing areas of openSavannah.It was during this time that Australopithecus africanus emerged. (Australopithecus Means "southern ape'.)In order to survive,africanus had to forsake the vegetarian and fruitarian existence of the related hominid Australopithecus robustus,and change to a scavenging and hunting existence that was largely carnivorous.The molar teeth of africanus had the shape and thin enamel of a carnivore.The jaw muscles were small and did not need the crested cranium of robustus for their attachment.The canines were also small,for africanus killed neither with fangs nor with8claws or horns,but with weapons,having adopted a completely erect posture,which freed the arms and hands from the need to be used for locomotion.Africanus's earliest weapons were bones;only later did stones begin to be used,and still later the axe.Thus it appears that for at least two million years our ancestors were largely meat-eating.From that time,they continued to be scavengers and hunters,seeking their favourite food of meat andoffal.They had one advantage over the more strictly carnivorous species,in that they could and did eat vegetable foods too.Along with meat,their diets contained the nuts,berries,leaves and roots that had fed their forebears.This omnivorous potential gave them the ability to survive when their prey eluded them or was scarce.In nutritional terms,the diet of prehistoric human beings and their ancestors during perhaps two million years or more was rich in protein,moderately rich in fat,and usually poor in carbohydrate.If we assume that our present universal taste preferences for the sweet and savoury are a continuation of preferences acquired long ago,then it is likely that,except in times of hunger,the small amounts of dietary carbohydrates will have come mostly fromfruits,as opposed to the less palatable leaves and roots.
2.2The two food revolutions
Until very recently in evolutionary terms,allanimals,including human beings,depended for their food supplies on hunting or scavenging other animals,or on the consumption of wild vegetation.It was less than10,000years ago-compared with the two million years or more of carnivorous ancestry-that webecame,uniquely,food producers.Agricultural food production seems to have originated independently at three different times in three different parts of the world,from which it then spread.The first was around10,000years ago in the Fertile Crescent,in what is nowIsrael,Jordan,Syria,Turkey andIran,with the cultivation of wheat,barley,lentils and peas,and the domestication ofcattle,sheep and goats.About7,000years ago agriculture began inChina,producing rice,soybeans,yams and pigs.The area that came last to agriculture wasCentral America,where the chief crops were maize and beans,and where llamas and guinea-pigs wereraised.In most instances,their food production began with the cultivation of cereals.This derived from the discovery that some of the wild grasses whose seeds were occasionally eaten could yield many times that amount of edible seeds if they were deliberately planted.The domestication of these grasses produced the cereals that are now the staple food of a large part of present-day humanity and it was followed or accompanied by the domestication of rootcrops,and of wild animals that were used both for food and as animals ofburden.The results of the discovery of agriculture-the Neolithic revolution-were many and far-reaching.Human beings ceased being nomads and began to live in settled socially organized communities.This landmark of progress became the basis for all that we know of civilization,with its arts,its inventions and its discoveries.Compared with hunting and foraging,agriculture usually yielded more food;it also allowed the cultivation of areas where existing resources of food would have been inadequate.Thus the human population grew,because fewer died of food shortage and because people spread into increasing areas of the earth's surface.But in due course the limits of food production again became the limits to the numbers that could be fed.The inevitable pressure of population on food supplies tended to produce and stabilize a type of diet quite different from that of our hunting ancestors.It was-and still is-much easier to produce vegetable foods than animal foods;for a given area of land,some ten times as many calories can be produced in the form of cereals or root crops than in the form of meat, ·eggs ormilk.The effect of the Neolithic revolution was thus to alter the components of the diet so that it was now rich in carbohydrate and poor both in protein and in fat.The carbohydrate was overwhelmingly starch,with sugars supplied only to a small extent as before by wild fruits and vegetables.It is likely that deficiency of protein and of many of the vitamins began to affect large sections of the human species only after they became foodproducers.Human beings,like all animals,constantly face recurring periods of food shortage.Although the Neolithic revolution increased total food supplies and radically changed the composition of our diet,hunger and famine did not vanish.For most of the time,wind,drought,flood and our own exploitation of the land have combined to limit food production to levels lower than those necessary to feed all our offspring.It is only in the last few decades that a sizeable proportion of people-though still only a minority-have been born into a situation where it is likely that they will never know real hunger throughout theirlives.The reasons for this second revolutionary change are the cumulative effects of science and technology.I need only list a few of these to show the extent of this revolution and its effect upon the availability of food to mankind:genetics and the breeding of improved varieties of plants and animals for food;engineering and its effect on drainage and irrigation;the discovery of syntheticfertilizers,weed killers and pesticides;the internal combustion engine and its effect upon transport by sea,land and air;modern methods of food preservation by canning,dehydration,deep freezing.I could cite many more examples of changes that have given humanity the possibility of producing and preserving much more food than has ever been available to any otherspecies.As a result,in the affluent countries a large proportion of the populations has a very wide choice of foods,irrespective of season or geography.The effect has been that these people are able more and more to choose foods that please their palates,and not simply foods that fill their stomachs.The first and most obvious result has been an increase in the consumption of more palatable foods,such as meat and fruit.And because of the basic association between palatability and nutrition,there has come a simultaneous improvement in the nutritional standards in these groups,just as there has always been a better level of nutrition in the much smaller section that comprises the wealthy members of any population.The advances in agricultural techniques and general technology have had an effect not only on the yield of food and the availability of food.They have also had a tremendous effect on the way foods can deliberately be changed by extractions and additions,so that quite new foods can be made that do not exist in anything like these forms in nature.Some of these manufactured foods have been in existence for quite a long time-bread,for example,and tortillas andchapattis and cakes and biscuits.But most of them have been produced,or vastly improved,only in the past century or two or in recent decades.I am thinking now of ice cream and soft drinks,an enormous range of chocolate and confectionery,and new sorts of snacks in the form of sweet and savoury biscuits.And there is now a new range of "meat'products made from textured vegetable or microbial protein.We can do all these things largely because nutritional value and palatability are two different qualities.As I pointed out,although we can use as food almost any sort of animal or vegetable material,our preferences are for the particular palatability qualities of meat and of fruit,which together can supply all the nutrients we require.We are only just beginning to emulate the taste and texture ofmeat;and people will be eating and relishing significant quantities of the new vegetable or microbial protein foods only when the food manufacturer imparts to them qualities that make them much more attractive than he has been able to do up to now.But for some time industry has been able to isolate an essence of sweetness,which has the property of imparting a very desirable palatability to a wide range of foods and drinks.People do not demand a particular flavour and texture to go with sweetness,although they seem to demand only a very limited range of flavours and textures to go with savouryfoods.The human avidity for sweetness could for vast periods of time be satisfied almost exclusively by the eating of fruit;rarely,and in very small quantities,our ancestors might be lucky enough to find some honey produced by wild bees.But some time after the Neolithic revolution,perhaps only2,500years ago,people found that they could produce a crude sort of sugar by extracting and drying the sap of the sugar cane.This first began to be cultivated probably inIndia,and its cultivation slowly spread toChina,Arabia,the Mediterranean,and later to South and West Africa,the Canary Islands,Brazil and theCaribbean.In spite of this increasing area of cultivation,the cost of the sugar,crude as it was,was extremely high,so that by the middle of the sixteenth century it was said to be equivalent to the present cost of caviar.Compared with the price of foods such as butter or eggs,it has been calculated that the price of sugar has fallen to about a two hundredth of its price in the fifteenth century.Even as late as the eighteenth century,sugar was a luxury,and until a hundred years or so ago domestic sugar boxes were often provided with lock andkey.It was chiefly the development of the sugar plantations in theCaribbean,based on the slave trade,that set the pattern of the sugar industry in the form known today.The demand for sugar was so great,and its production so lucrative,that tremendous improvements began to be made from about the middle of the eighteenth century in the production of high-yielding sugar cane (and later the sugar beet);in the efficiency of the extraction of the sugar and the making of raw sugar;and finally in the process of refining thesugar.Thus,the price fell constantly,the demand grew,and consumption rose to exceedingly highlevels.Legislators in many countries have often taxed sugar to provide revenue,just as they have often taxed tobacco and alcohol.And sugar also resembles alcohol and tobacco in that it is a material for which people rapidly develop a craving,and for which there is nevertheless no physiologicalneed.I am saying,then,that human beings have a natural liking for sweet things;that primitive people could satisfy this desire by eating fruit or honey;and that in eating fruit because they liked it,they obtained necessary nutrients such as vitamin C.But now we can satisfy the desire for sweetness by consuming foods or drinks that provide little or no nutritional value except calories.It is possible today to get an orange drink that is more attractive in colour than true orange juice,is sweeter in taste,has a more aromaticflavour,is cheaper to buy-and can be guaranteed to contain no vitamin C Whatever.Since people chiefly seek palatability in foods and drinks,the sale of these drinks increases all the time.One day it will no doubt be possible to manufacture from some non-digestible polymer a hamburger that looks more attractive than a real meathamburger,and smells and sizzles better on the barbecue,at only half the price.It will be entirely "pure'in that it will contain neither protein nor vitamins or minerals.And who will say that we shall not buy this super,space-age,new food just because it has no nutritional value.We shall buy it because we like it,and only because we like it.Most people still believe that foods that are palatable must have a high nutritional value;many also believe what is equallyuntrue:that foods with little flavour have no nutritional value.I am certain that it is the dissociation of palatability and nutritional value that is the major cause of the "malnutrition of affluence'.For thisreason,let me give you one or two more examples of how one can no longer expect the two qualities to be foundtogether.First,you may remember beef tea,which even in this century was commonly given by doctors to their convalescent patients as a "restorative” .And to this clay many mothers believe that a tasty clear soup is nourishing for their children.Yet here is high palatability with virtually no nutritional value.Second,the economics of chicken farming has produced a broiler chicken which,because it is slaughtered young,and because of the speed with which it is eviscerated,has less flavour than a free-range chicken.Yet its nutritional value is no different,even though its lower palatability is often referred to as indicating a lower nutritional value.Some time ago I read a short story,the title and author of which I have unfortunately forgotten.A brilliant chemist became tired of his mistress and decided to get rid of her by using his professional skill.He devoted himself to developing a new and exquisiteflavour,which he then incorporated into chocolates,sending box after box to his mistress.Finding these quite irresistible,she consumed them in inordinate quantities until she died of over-eating.The chemist knew that her craving would alone suffice to kill her.One more example of the strong power of palatability is the story of the snake that ordinarily will eat only toads.It will not,for example,eat pieces of meat such as beef.But you can make it do so by rubbing the beef on to the skin of the toad and so presumably making the beef taste oftoad.One argument used by the health food people to demonstrate the poor nutritional value of modern processed foods is to claim that they have little flavour.Their own products,they say,must be nutritionally superior because they taste better.Much of what I have to say in this book is based on the proposition that satisfying our palates is no longer a guarantee that we are satisfying our nutritional needs.
.Sugar and other Carbohydrates
The different sorts of sugar,including sucrose and glucose,all belong to a group of substances known as carbohydrates.Since we shall be talking of these substances from time to time,let us look at the whole group for a moment.The carbohydrates in our diet can be divided into those that the body can digest and absorb from the gut and those that cannot be absorbed;they are sometimes referred to as "digestible and indigestible",or "available and unavailable'.The unavailablecarbohydrates,which pass through the body virtually unchanged,makeup the greater part of what is now known as fibre and used to be called roughage.This mostly consists of cellulose,the chief constituent of cotton and ofpaper.The available or digestible carbohydrate of the diet consists almost entirely of sugars and starch.They are all made up of units called monosaccharides.Chemists apply the word "sugar”to anyone of a particular group of substances that have similar properties but are not identical.Some of the better known sugars are glucose,fructose,maltose,lactose and sucrose;these are either monosaccharides ordisaccharides.The best known monosaccharides-sugars made up of single units-are glucose,fructose and galactose.Glucose is the first product of photosynthesis in plants,and is the main source of energy for both plants and animals.Fructose,together with some glucose and sucrose,is found in fruits.Galactose exists only in the animalkingdom,as part of milk sugar-lactose.Glucose is a sugar found,usually with other sugars,in some fruits and vegetables.It is very important to biochemists,biologists and nutritionists because it is a key material in the metabolism of all plants and animals.Many of our principal foods are sooner or later converted in the body into glucose,and it is one of the most important substances that is metabolized (oxidized or burned)in the tissues to supply energy for everyday activities.There is always glucose in the bloodstream,and this is usually called "blood sugar'.In healthy people,a complicated interaction of a number of hormones contrives to keep the level of the blood sugar fairly constant.If you eat ordinary sugar or starch,or one of several other substances,glucose will be released during digestion and this will be absorbed from the alimentary canal into the blood.The level of blood glucose therefore rises.Immediately,however,there is an outflow of hormones,especially insulin from the pancreas,into the bloodstream;the effect of this is to lower the level of glucose towards its normal level.This works chiefly by converting it into a polysaccharide (made of many monosaccharide units)called glycogen and tucking this away in the muscles and liver,where it can be called upon again to release glucose if the level in the blood falls.Sucrose,the chemical name for the subject of this book,is one of three common disaccharides.It is made up of one unit of glucose joined to one unit of fructose.When digested,a mixture of equal amounts of glucose and fructose,called "invert sugar',is produced.There is reason to believe that it is the fructose part of sucrose that is responsible for many of the undesirable effects of sucrose in thebody.There are two other disaccharides to be found in humandiets.One is maltose,made up of two units of glucose joined together.This is produced during the digestion of starch,for example when grain like barley begins to germinate,or when starch is in the mouth ·being chewed,or when it reaches the intestine.It is later digested to glucose.The third disaccharide is lactose,produced by the joining together of two monosaccharides,glucose and galactose.It occurs only in milk,or in foods such as yoghurt that are made from milk and that include the water part.Large quantities of lactose cause diarrhoea,and even relatively small quantities have this effect on people with lactose intolerance.However,such people are not affected by small amounts of milk-say,up to a pint a day taken at intervals.They also tolerate cheese,since most of the lactose remains in whey when cheese ismade.Starch,which occurs as a store of energy in plants,is made up of many glucose units joined together and is therefore called a polysaccharide.It is easily digested either by enzymes in the body or enzymes extracted from moulds,or by heating in solution withacid.The effect is to break down the starch into smaller and smaller pieces.The early stages result in the production of dextrins.Later maltose is produced,and finally glucose.Glycogen,as we saw,is another polysaccharide,found in the liver and muscles of animals.Like starch it is a store of energy,but unlike starch it is present in relatively small quantities:the total amount of glycogen in an adult human body is no more than350grams.Cellulose is also a polysaccharide,but is not digestible.
.Where sugar comes from
The sugar with which this book is concerned is what most people simply call "sugar'.It is sometimes called "cane sugar',although in fact about one third of the sugar consumed comes from beet.Chemists call it "sucrose'.In this chapter we discuss where it comes from and how it is prepared;we shall then look at the effects it can have in thebody.Nearly99per cent of the sugar we consume is made from sugarcane or sugar beet.The other one per cent comes from such sources as the maple in New England andCanada,the palm inIndia,and millet in the southernUnited States;quite tiny quantities are also sometimes made from grapes,carob beans or dates.In spite of popular belief there is no difference in taste or any other ordinarily recognizable property in refined sugar isolated from the cane or the beet.Each contains more than99'9per cent pure sucrose.Only the most sensitive analytical techniques can detect differences due to the presence of minute quantities of substances characteristic of one or the other.
Like the cereals,the sugar cane (Saccharum officinarum)belongs to the grass family.Its original home was apparently somewhere in Asia,possiblyIndia.It has been cultivated for2,500years and its wild ancestor is no longer known.It now grows mostly in plantations in many parts of the world.Cultivation probably began inChina andIndia before500BC;in325BC the soldiers of Alexander the Great inIndia spoke of "honey not from bees'.Cultivation spread westwards,reaching Persia (by AD500),Egypt (640),Sicily and Cyprus (700),Spain (755),and later Madeira,the Canary Islands,North America,Mexico and-by the beginning of the sixteenth century-the Caribbean.The cane requires a warm climate,rainfall of at least60inches a year or adequate irrigation,and plenty of fertilizer.The countries producing the greatest quantities of cane sugar are shown in thetable.
The history of sugar cane cultivation in theCaribbean can hardly be a source of pride to humanity.The Europeans-fromPortugal,Spain,Holland andBritain-who first took the sugar cane to theWest Indies rapidly overcame the indigenous population of Caribs And then proceeded virtually to exterminate them.They solved the problem of providing the labour force needed in the sugar plantations by bringing slaves fromAfrica.Thus was established the infamous "triangular trade'.Rifles,cloth and other goods were shipped to the west coast ofAfrica where they were given to the African chiefs in exchange for slaves captured in the interior.These Were herded into the holds of ships and taken to theCaribbeanIslands such asJamaica and St Kitts.Those that survived the horrendous conditions of the journey-often less than half-were then used on the plantations.The raw sugar from the islands was shipped back to Europe-especially toEngland-for refining,thus completing the triangle.The appalling conditions in the ships and the plantations caused so many deaths that the supply of slaves had to be constantly replenished by fresh imports fromWestAfrica.In the earliest days cane sugar was simply the dried juice that had been pressed from the cane;a similar product known as "gur'or "jaggery”is still made inIndia.Most sugar used nowadays,however,is refined white sugar.Sugar from the cane is usually produced in two stages-the extraction of raw sugar,and then the refining of this to white sugar.The sugar cane is cut by hand or,increasingly,by machine;the tops and leaves are removed and the canes brought rapidly to the factory.There they are cut,crushed,shredded and passed through roller mills which press out about two thirds of the juice.The crushed fibre,known as "bagasse” ,is sprayed with a little water and passed through another set of roller mills.The quantity of dried bagasse produced is more than enough to provide for the energy needs of the factory;the surplus is sold to local generating stations or for paper manufacture,or mixed with molasses for animalfeed.The juice pressed out of the cane is at this stage a turbid greenish liquid containing some97.5per cent of the sugar originally present.About16per cent of the juice consists of dissolved or suspended solid matter,of which85to90per cent is sucrose.The juice is now heated to boiling point and lime added.This produces a copious precipitate,which rapidly settles as "bottoms',leaving clarified juice above.The "bottoms'are spread over the fields as "mud',acting as a fertilizer.The clarified juices are evaporated,first in open vessels and then in vacuum pans.Eventually the sugar begins tocrystallize,becoming "massecuite',a mixture of sugar crystals and syrup.These are separated by spinning in a centrifuge at up to1,200revolutions perminute.The result is two products-raw sugar and cane molasses,or syrup.The molasses are boiled twice more,and the process of crystallization and centrifugation is repeated.After the third boiling there is usually not enough sugar left in the molasses to make it worth trying to extract more as crystals.The final molasses,with whatever sugar it does contain,is used in a variety of ways-for example,to make rum or yeast or cattlefood.The raw sugars produced by the three boilings are progressively darker in colour:the lightest is called demerara,even though most of it no longer comes from the part ofGuyana bearing thatname;the second crop of crystals is called light muscovado and the third crop darkmuscovado.The next step is for the raw sugars,either separately or mixed together,to be sent to the consuming countries,where they are processed into refined whitesugar.The raw sugars are washed and then dissolved ("melted')in water,and the solution is decolorized by passing it through columns of charcoal.It is then put into vacuum evaporators and boiled until the concentration of sugar becomes high enough for crystallization to take place.This is started when a small quantity of crystals is thrown into the concentrated syrup,the precise timing determining the size of the.new crystals.The contents of the evaporator,a mixture of crystalline sugar and syrup,are now transferred into largecentrifuges,each with an inner perforated basket in an outer cylinder.Rotation of the basket results in the syrup being forced through the perforations while the crystals remain behind.If sugar cubes are required,the wet mass is poured into a shallow flat tray which is covered with a lid and passed slowly through a heated chamber.The Resulting thin slab of sugar is chopped into cubes by a sort of multipleguillotine.Some cane juice,instead of being evaporated to make rawsugar,may be processed in the plantation factory,producing what is known as "plantation white'.This may be done by "sulphitation',in which sulphur dioxide is passed into the limed juice so that calcium sulphate is formed.Alternatively,calcium phosphate may beproduced in the juice,or both phosphate and sulphite.Rarely,thecane sugar juice is treated by the carbonation process which isroutinely used for beet sugar juice.Whichever method is used,thevirtually clear,colourless juice is filtered off and dried in evaporators togive plantation white sugar.
The sugar beet,Beta vulgaris (sub-species circle),grows as a white root,and is related to the common red beetroot and to the mangold.It grows well in temperate climates,requiring a deep,limy loam that is well drained.The discovery that sugar beet might be a source of sucrose was made by the German chemist Marggraf in1747.It was,however,not until the Napoleonic Wars That another German,Achard,working inFrance,demonstrated that it could be refined on a commercial scale.Its main advantage was that,unlike sugar cane,beet could be grown in temperateclimates,andFrance began producing beet sugar in18n to avoid the effects of the Allied blockade which was preventing the import of canesugar.Since the molasses from sugar beet is so bitter as to be unacceptable to the human palate,no attempt is made to extract raw sugar from the beet;processing is a single operation leading directly to the production of refined sugar.First the washed beets are sliced into strips,or "cosettes”.The extraction of the juice is carried out by diffusion,in a series of a dozen or so cells.The sliced beets pass along from cell to cell in one direction,while water enters at the other end and passes from cell to cell in the opposite direction.Thus,at one end,fresh beet slices enter and sugar-rich juice iswithdrawn,and at the other end freshwater is admitted and the exhausted beet slices discharged.The juice then goes through the process of refining in the same way as for cane sugar.Brown sugar can be produced by mixing some cane molasses or caramel with the refined white beet sugar,as is sometimes done with refined cane sugar.About half of the white sugar consumed in theUK comes from the sugar beet,the other half from the cane.
.Is brown sugar better than white sugar?
By far the greater part of sugar from the cane ends up as refined white sugar;a small quantity is sold as brown sugar.But not all the brown sugar available to the consumer is this unrefined raw cane sugar.Some,as we have seen,is manufactured from white refined sugar-either from cane or beet-by the addition of molasses or caramel.Unfortunately,it is legally permissible to describe as "demerara”the light brown sugar made in thisfashion,which bears a superficial resemblance to the raw sugar produced in the firstboiling.The characteristics of the unrefined raw sugars depend on several factors.First,there is an increasing proportion of molasses trapped within the sugar crystals as the syrup passes from the first to the third crystallization,producing first demerara sugar,then light muscovado and dark muscovado.Thus,each successive sugar is of a deeper brown colour (accentuated by the greater degree of caramelization caused by repeated boiling and crystallization)and has a stronger flavour of caramel and molasses (known as treacle inBritain).But other factors are also involved.Strains of sugar cane produce juices containing differing amounts of substances with various undesirable qualities,some of which will adhere to the sugar during crystallization.By choosing an appropriate strain of cane and taking care to keep extraneous materials out of it when it is harvested and cut,the raw sugar produced can be made to consist of clean,evenly sized,bright crystals with an attractive brown colour and a pleasant taste and aroma.Without these standards of diligence and care,the same general process can yield a dirty product containing easily observable non-sugar particles mixed with uneven particles of dull brown sugar,the whole having an unattractive aroma.This is especially noticeable in the crystallization of the darkmuscovado;but may be detected too in demerara.This does not matter if the raw sugar is produced as an intermediate stage on the way to the refinery.However,some of this dirty raw sugar,not really fit for consumption,is put on the market side by side with the clean raw sugar intended from the outset to be consumed in the unrefined state.You can see the difference in quality if you closely examine just a teaspoonful,placed on a white saucer and shaken into a thinlayer.Careful inspection will also show the difference between these unrefined sugars and the brown sugars made by adding molasses to white sugar.With the latter,you will notice that the colour is only on the surface,and a quick rinse with a little water will reveal the white crystals of sucrose.In theUK,however,this kind of testing should be unnecessary,since labelling makes it easy to distinguish these two kinds of brown sugar.The raw sugars are labelled as "unrefined'or "raw',and the country of origin is given.The coloured white sugars have to be labelled so as to indicate their ingredients.The wording will be something like "Ingredients:cane sugar,molasses'.These sugars are also likely to be given some such description as "light brown'or "dark brown'or "London demerara”or "golden granulated'.There was a time when brown sugar,like brown bread,was considered to be less pure and less desirable;it was also less costly then.As a result it was the wealthier people who ate white bread and white sugar,while it was an aspiration of the less wealthy to be able to do the same.But from time to time a minority took the view that,far from the brown colour indicating a degree of impurity,it indicated that the food was better because it had not been deprived of some important nutritiouscomponents.Unlike brown bread,however,which is almost always bread made from flour produced from whole wheat or lightly milled wheat,a great deal of the available brown sugar is made,as we saw,by the addition of caramel or molasses as a coating to crystals of refined white cane or beet sugar.Many of those who buy brown sugar do so in the belief that they are buying raw sugar;this does not matter much if the brown sugar is bought because of its taste.The situation is altered,however,if it is bought in the belief that it retains some nutrients that are removed when raw sugar isrefined.The conventional view of the nutritionist used to be that neither coloured white sugar nor raw sugar contains anything that gives it’s significantly higher nutritional value than that of refined sugar;I too held this view when I wrote the first edition of this book.Since that time,however,my colleagues and I have carried out a series of experiments that showed that at least some raw sugars may contribute to the nutritional value of adiet.We decided to do these experiments because of the publication in1981of a series of reports describing research carried out in several laboratories in theUSSR.These compared the effects in rats and mice of feeding diets containing either white (refined)sugar or brown (unrefined muscovado)sugar.The animals fed the brown sugar were reported as showing more rapid growth,prolongedlife,less increase in the concentration of cholesterol in the blood,largerlitters and a better metabolic picture,especially in relation to carbohydrate metabolism.The Soviet workers claimed that these beneficial properties of the brown sugar resided in a number of complex organic substances to which they gave the name "biologically active substances' (BAS).Their results were sufficiently striking for us to examine these claims in our own laboratory.We made up our usual sort of laboratory diet,which contained protein,fat,vitamins and mineralsalts,together with either refined sugar or brown muscovado sugar or pure starch.We fed our rats from the age of three weeks with one or other of these diets.Our results were very different from those reported by the Soviet workers.We could not confirm theirclaims;the different sugar diets produced the same growth rate,size of litters and carbohydrate metabolism.The only differences were the usual ones we had discovered between rats fed sugar and rats fedstarch.After about two years of experiment we were about to discontinue our research when we decided to carry out one last investigation.We thought it would be interesting to see what the effect was,not simply on the rats themselves but on their pups.We therefore allowed the pups to stay with their mothers until they were ready to be weaned at three weeks or so.To our surprise,about half of the pups born to mothers fed starch or white sugar died when they were between10and15days old,whereas most of those born to mothers fed brown sugar survived until they were weaned at22or23days.We repeated these experiments several times,until about300pups had been born to mothers on each of the three diets.Of the total of909pups born,the survival score was37per cent from mothers fed starch,53per cent from mothers fed white sugar,and almost90percent from mothers fed brown sugar.What is more,every one of the "starch pups'and "white-sugar pups',even those that survived,were clearly ill,with swollen abdomens and weak hind legs;on the other hand none of the "brown-sugar pups'showed these abnormalities.We were unable to identify whatever it was in the brown sugar that kept the pups alive and well.We did,however,get as far as showing that it was not some complex "biologicallyactive substance”,since the effect was still demonstrated when we incinerated the sugar to ash.This burnt off all the organic material as well as the sugar itself,leaving only mineral salts.When this ash was added to the mother's'white-sugar diet most of the pups survived,just as they did when the mothers were fed on the brown-sugar diet.
What conclusion can we draw,then,about the comparative value of the white and brown sugars?First,we can be sure that the coloured brown sugars have no measurable nutritional advantage over white sugar;even when the only addition is molasses,the quantity is far too small to contribute anything worthwhile.Second,we have not found so far that raw sugar modifies any of the undesirable effects of white sugar.But,third,I have to say that the dark muscovado sugar,which carries with it a sizeable proportion of the molasses from which it crystallizes,does contain some materials that in some circumstances can contribute to the nutritional value of the diet.We carried out our experiments not so much because we thought they might tell us something directly about the effect of raw sugar on the health of baby rats,but because the whole process of reproduction-pregnancy,giving birth and lactation-is a period of physiological stress.A diet that is for most purposes just adequate is more likely to show a marginal nutritional inadequacy when such a physiological stress is imposed.If,then,I am asked whether one should eat brown sugar or white,my answer is in two parts.First,for reasons that are explained in the rest of this book,I strongly believe that it is better not to eat sugar at all.Second,if you feel that you must take sugar,then it makes sense to eat brown sugar,provided it really is a good quality raw sugar:you should choose a clean,dark muscovado sugar,which contains the greatest proportion of molasses and so of the unidentified nutrients.You should also remember that it is white refined sugar that is used by the manufacturers of all the common soft drinks,ice cream,confectionery,chocolate and sweet cakes and biscuits.
.Refined and unrefined
It is popular nowadays to speak of "refined'and "unrefined'foods,and in particular of "refined'and "unrefined'carbohydrates.These terms are most often used in speaking of white sugar and of bread made from white flour.I deplore this custom for tworeasons.The first is that the refining of sugar and of flour are not really comparable.White flour is made by the removal of the bran and germ,and perhaps some of the outer layers of the endosperm,the innermost part of the wheat berry.Everything that has been removed is in fact edible,and would have been eaten if the whole of the berry had been ground.Such flour would contain100percent of the wheat berry;what is called wholemeal flour consists of92per cent of the wheat berry,and white flour usually about72percent.On the other hand,the first stage in producing sugar from the cane is the preparation of the cane juice,which leaves behind the major part of the cane as inedible fibre and associated gums and insoluble materials.The following stages of clarification,precipitation,concentration and crystallization remove further unwanted materials,so that the resulting "unrefined'raw sugar represents only a small proportion of the original cane from which it was produced.This product is far removed from the original sugar cane;the fibrous bagasse from which the cane juice is extracted,and the materials removed from the juice,amount to well over80per cent of thecane,and what is removed is either inedible or undesirable.Raw cane sugar thus consists of about20per cent of the original sugarcane,white cane sugar of perhaps15or16per cent.It does not make sense,therefore,to imply that unrefined sugar is somehow the "whole”or "natural'product of the sugar cane,while refined sugar is in some way "unnatural'or "de-natured'.Thus,while the use of these terms,much as I dislike them,may to some extent be justified in regard to wholemeal flour and wholemeal bread,they are invalid where sugar isconcerned.There is a second reason for pleading that you do not speak of refined and unrefined carbohydrate.It is true that refined sugar is the pure carbohydrate sucrose,while raw sugar is mostly this carbohydrate with small quantities of other materials.On the other hand,white flour is not,as some people imagine,virtually nothing but the carbohydrate starch.For example,white flour contains only fractionally less protein than does wholemeal flour-about13percent instead of about13 ·5per cent.And in many countries such as theUSA and theUK some of the vitamins that are partly removed in the milling process are replaced by the flour millers.Moreover,other nutrients are sometimes added to a much higher level than was present in the original wheat grain-for example,calcium in theUK.Altogether,then,it is wrong to call white flour or white bread "refined carbohydrate'.And particularly it is not sensible to put on the same nutritional level raw sugar and wholemealbread,or white sugar and white bread.
There are many who consider that the dietary change most relevant to the pattern of disease in Western countries is the change from diets with a high proportion of unrefined foods to diets with a high proportion of refined foods.The evidence for this claim is largely the fact that the diets of people living in rural areas ofAfrica consist largely of fibre-rich unrefined cereals,and it is in these areas that coronary thrombosis and other diseases of affluence are rare.In the West,where these diseases arecommon,we have changed from eating brown bread to eating white bread,so that our diet now provides substantially less fibre.This idea is based on the assumption that cereals are a sizeable and "natural'part of the human diet.This is,literally,a short-sighted view:cereals entered our diet less than10,000years ago,which is about one half of one per cent of the period since we emerged as a separate species.Before this,for at least two million years,our ancestors were-like all other species-hunters and gatherers of food.The brief period since the advent of agriculture,which resulted in a diet containing large quantities of starch-rich,high-fibrefoods,such as cereals,is far too short for the human species to have completely adapted to such a diet.In other words,there has been far too little time in evolutionary terms for there to have been a significant genetic change towards any adaptation that may have been necessary for such a diet,and if our present-day diet is lower in cereal fibre than that of,say,a hundred or so years ago,then the trend is towards the sort of cereal-free diet eaten by our pre-Neolithic ancestors.This is one reason why I have not accepted the view that lack of fibre may be responsible for the diseases of affluence.A second reason is that,as we shall see,evidence gained by comparingpopulations ("population epidemiology')can be very misleading.People In rural Africa or other parts of theThird World live very differently from those in industrialized and urbanized parts of the world.Not Only do we take less fibre,but we take more meat,fat,milk,sugar and a range of other foods;we eat more in total;we are less active physically,smoke more cigarettes and are more subject to industrialpollution.Finally,the experiments that have revealed the considerable changes in the body's metabolism that sugar can produce involved comparing diets containing pure starch (or "refined'flour)with diets containing pure sucrose.The many differences in the effects of the two diets could not,therefore,have been due to the presence or absence of fibre,but must have resulted simply from the presence or absence of sugar.
.Not only sugar is sweet
The most obvious property of sugar is its sweetness,but it has several others:it aids preservation,provides bulk in confectionery,enhances flavour and appearance by caramelizing.with heat,gives "mouth feel'to soft drinks,promotes the gelling of jam and marmalade and provides calories.Alternative sweeteners fall into two groups.One provides sweetness,but virtually none of the other features I have mentioned;the other provides sweetness together with calories and several,if not all,of the other functions ofsugar.
The caloric sweeteners are either sugars or they are chemically related to one or other of the sugars.Glucose and fructose are the two sugars most commonly used.Glucose,sometimes called dextrose,is made very easily from starch,which,as we saw,is a large molecule made up of glucose units joined together.When starch is treated with acid or alkali,or with appropriate enzymes,it splits into its component glucose units.Much of the glucose in confectionery is used in the form ofsyrup,for example corn syrup made from maize starch.It is less sweet than ordinary sugar.Sucrose,you will recall,consists of a combination of glucose with an equal amount of fructose.Fructose seems to be the part of the sucrose that produces most of the ill-effects of sucrose.It is nevertheless often used instead of sucrose for diabetics,because it does not create an immediate need for insulin,as glucose does.One other possible advantage of fructose is that it is nearly twice as sweet as sucrose,so that less,with fewer calories,is needed to produce the same degree ofsweetness.During the past twenty years or so,it has become increasingly practical to produce a mixture of glucose and fructose fromstarch,which previously could only be made to yield glucose.Theprocess,developed inJapan,depends on the use of an enzyme'called glucose isomerase,which converts the glucose into fructose.By manipulation of the conditions,the proportion of glucose converted to fructose can be varied,producing a mixture with about equal proportions of glucose and fructose (as in invert sugar),or with up to90per cent fructose.The final product is usually not crystallized from the solution in which it is produced,being transported and used as "high fructose syrup' (HFS).This is now used on quite a large scale,especially in theUSA andJapan,as an alternative to ordinary sugar.Manufacturers can switch from sucrose to H F Sand back according to the fluctuations in sugar and starch prices.Because of this,the farmers inEurope who produce sugar beet have persuaded the EEC authorities to put a levy on HFS production and a quota on itsimport.The non-sugar caloric sweeteners are made from sugars,and are what chemists call "polyols'.By the process of chemical reduction-adding hydrogen atoms,for example to fructose,so that one more alcohol group is formed and added to the five already present-sorbitol is produced.Other polyols that can be used include maltitoland xylitol.They all provide,in a given quantity,about the same number of calories as ordinary sugar (sucrose);however,as they are not as sweet,you would tend to use more,and so take in more calories.These caloric sweeteners are therefore of no help in a slimming diet,but sorbitol is sometimes recommended as an alternative to ordinary sugar for diabetics,and xylitol has been used in candy and chewing gum because it does not harm the teeth.A major disadvantage in these polyols is that,unless taken in fairly small quantities,they tend to causediarrhoea.The non-caloric sweeteners have no chemical relationship to the sugars and are very much sweeter,so that only tiny quantities are used.For this reason they are sometimes called "intense sweeteners”.They have mostly been discovered accidentally in research laboratories where chemists were synthesizing new chemical substances for quite other purposes.They can be used to assist weight loss through reduced calorie intake;to help sufferers from diseases such as diabetes which affect sugar metabolism;to substitute for sugar in times of shortage,for example during war-or,increasingly,I am glad to say,to help to prevent the sugar-promoted diseases described in this book.The best-known non-caloric sweetener issaccharin,which was discovered in1879.Its use increased considerably during the sugar shortage of the FirstWorld War.Another widely used non caloric sweetener is cyclamate,discovered in1937;it is,however,at present not used in theUSA or theUK.A new,increasingly popular sweetener is aspartame.Because the non-caloric sweeteners do not have the properties of sucrose in providing bulk,preservative power and so on,they are used almost exclusively as so-called table-top sweeteners,to be added to tea or coffee,or else in the manufacture of low-calorie cold drinks.To a small extent they may also be used in home cooking,in the preparation of some items such as fruit salad.Their lack of bulk,however,rules them out as sugar substitutes inmost desserts,confectionery and icecream.From time to time suspicions arise that the alternative sweeteners could be harmful.This happens most often in relation to the noncaloric sweeteners,presumably on the grounds that most have a chemical composition quite different from that of any of the natural sugars,or,indeed,of any naturally occurring substance.The suspicions usually arise from some superficial or incomplete research that does no more than hint at some possible harmful effect detected in,for instance,laboratory rats which have been fed the sweetener.The result is usually great contention and the setting upof.amuch,more extensive investigation.In these circumstances,tests are often carried out with phenomenally large doses of the sweetener;a recent test with saccharin used quantities that in a human being would require the daily consumption of,for instance,several hundred cans of soft drinks sweetened solely with saccharin.This much saccharin would have the sweetening power of some5kg of sugar aday.It is worth spending a moment here on the question of the toxicity of substances that accidentally or intentionally may find their way into our food.The most important fact to remember is that there is really no such thing as something being poisonous,or something not being poisonous,just like that.What matters is not only the nature of the substance,but also its quantity.No substance is intrinsically harmless;you can make yourself dangerously ill by taking large quantities of water.No substance is intrinsically harmful;it was fashionable in the early part of this century to give medicines containing arsenic as a tonic,although of course the quantities were very smallindeed.Similarly,if it turns out that cyclamate,or saccharin,or anything else,causes some undesirable effect in daily amounts that are fifty or one hundred times as much as anyone could possibly take-and even then only when taken over a period of ten years or more-it would not be sensible to ban itautomatically.In the USA the situation was complicated by what is known as the Delaney Clause,agreed by the US Senate in1958,which says that "no additive shall be deemed safe if it is found to induce cancer when ingested by man or animal'.This has been interpreted as forbidding the use as a food additive of any substance that,in any quantity,and over however long a period,produces cancer in any species of animal.It was this provision that led to the banning of cyclamate in theUSA in1970.This decision was based on the result of one experiment in which a small proportion of rats fed for a long time with very large doses of a mixture of cyclamate and saccharin developed cancer of the bladder.Within a week or two of the American Decision,theUK followed its example,so that cyclamate is not used by the food industry in either country,although the position is under review.However,16out of the17countries ofWestern Europe do permit the use ofcyclamate.Those people who are still concerned about the possible hazards of taking artificial sweeteners could reduce or abolish their cause for worry by using mixed sweeteners.This should reduce the possibility of being harmed by anyone of them,since each would be present in a lower concentration than if it were the sole sweetening agent.
At present,the better-known non-caloric sweeteners permitted in one or more of the countries that control food additives are saccharin,cyclamate,aspartame,acesulfame-K and thaumatin (talin).Their relative sweetness compared with sugar is given in thetable.For a variety of reasons,however,these figures are onlyapproximate.First,people's subjective assessment of sweetness varies.Second,the intensity of some sweeteners increases or decreases with the acidity of the food or drink to which they are added.Third,sometimes their relative sweetness changes with the degree of their dilution and the temperature of the food or drink.The non-caloric sweeteners are not entirely interchangeable.For example,saccharin and,to a lesser extent,aspartame are not stable to heat,so they are not used in the preparation of dishes that require prolongedcooking.In addition aspartame,being a compound of two amino-acids,aspartic acid and phenylalanine,may cause upset in children born with the condition of phenylketonuria (PK U).Such children are unable to deal with more than a small quantity at a time ofphenylalanine,one of the amino-acids found in most proteins.If more than this limited amount is taken regularly,a substance is produced that can cause mental impairment.Children usually grow out of PKU by the age of10years or so.Meanwhile the condition is controlled by giving the sufferer a carefully constructed diet containing sorts and quantities of protein that enable the phenylalanine intake to be limited.In addition,a child with PKU should be made aware of which soft drinks are sweetened with aspartame,and be taught to avoid these.
8.Who eats sugar,and how much?
People look at me quite incredulously when Itell them that there are now many parts of the world where theaverage person-man,woman and child-is eating more than100pounds of sugar a year-two pounds or more a week.But though this is true today,it has only rather recently become so and it still isn't true for all countries.In this chapter I want to tell you how sugar consumption has been changing,how much is being eaten in different countries and by people of different ages,and how much of western man's consumption is ingested by way of different sorts of manufactured foods and drinks,along with the sugar to which people help themselves from the bowl at thetable.Before going any further,I should emphasize that in this book I Am talking about the sugar (sucrose)produced from the cane and beet.This is technically called centrifugal sugar.I amexcluding sucrose produced from other sources such as the maple andthe palm;the amounts are negligible and come to only I percent or soof the total.I am also excluding milk sugar (lactose),as well asthe sucrose and other sugars one consumes in fruit and vegetables.The reason here is also chiefly quantitative;the amounts ofcentrifugal sugar are much greater than those of the sucrose from othersources.In one of our studies,we found that adults ate about half of their total carbohydrate as starch,35per cent as centrifugal sucrose,7percent as lactose and the remaining8per cent or so as the mixed sugars in fruits and vegetables-mostly glucose,fructose andsucrose.In the year1850world production of sugar was about1.5million tons.Forty years later it was more than5million tons,and by the turn of the century it was more than I I million tons.Except for a setback during each of the two world wars,production has continued to rise rapidly,so that it reached35million tons by1950and is now more than100million tons.Over the past100years there has been a25-fold increase in world sugar production;allowing36for the increase in world population,this represents an increasein average consumption from7pounds a year to45pounds.Themost extensive statistics of sugar production and consumption were collected25years ago in a report produced for the Food andAgriculture Organizationof the United Nations.Although this is nowlittle out of date,I shall quote some of its findings because theystill demonstrate many interesting features that are not easy todiscover from more recentstatistics.
During the20years from1938to1958,there was an increasein world production of many commodities.Among food items,cocoa increased by20per cent,milk by about30per cent,meat andfood grains up to50per cent,but sugar production outstripped allof these with its enormous increase:100per cent over the20years.Between1900and1957,consumption of sugar increased froman average of11pounds a year to34pounds;by now,as I said,itis about45pounds.But the increase has differed in different countries.It has been most rapid in the countries that until recently had a lowconsumption.Those countries thatalready had a high consumption have had a smaller increase or none atall;in theUnited Kingdom there was an increase from about100pounds to120pounds,while in theUnited States there has been nochange from the previous102pounds or so.It looks as if there is a limitof somewhat over100pounds a head a year at which all countriesstop increasing their intake.The wealthier countries graduallyachieved this high level by a slow and fairly steady increase over perhaps200years;some of the poorer countries are now achieving it very muchmore rapidly.The best statistics for anyone country over a long period are those for theUK.Just over200years ago we used to take4or5pounds of sugar (about2kg)a year;by the middle of the nineteenth century,this had increased five-fold to about25pounds a year;we now take about100pounds a year.Over the whole200years we have increased our consumption25-fold.To put this another way,200or so years ago we used to spend a whole year getting through the amount of sugar we now get through in two weeks.The apparent fall in the consumption of centrifugal sugar in theUK after about1970is almost exactly equalled by an increased consumption,largely in manufactured foods,of glucose and of small quantities of the recently introduced High Fructose Syrup
.Totalconsumption of all three forms of sugar has hardly changed in thepast20years or more.There are also some figures for other countries or populations.InSwitzerland,average intake has increased ten-fold in the last100years.Consumption amongst Canadian Eskimos increased muchmore rapidly;in one area,it rose from26pounds to104pounds ayear between1959and1967.The consumption amongst therural Zulu population inSouth Africa increased ten-fold in elevenyears,from six pounds a year to60pounds a year between1953and1964.
We have been looking at the way sugar consumption hasbeen going up especially during the last200years or so,and also atthe way sugar consumption differs in different countries-generally high in wealthy countries and low in poor countries.I shouldlike to say a little more about diets in rich and poor countriesbecause,although not directly related to sugar consumption,they do havea bearing on this,and they also give us a better picture of theway diets are affected by income.Let us look at the diets indifferent countries according to their average national income,andcalculate how many calories were supplied by these diets,how muchprotein,fat and carbohydrate,and how much of the carbohydrate wasmade up of sugar on the one hand and of other components-chiefly starch-on the otherhand.As you pass from the poorest to the wealthiest group ofcountries,you find an increase of about50per cent in the average numberof calories in the diet,from about2,000calories a day to about3,000.Protein increases by about80per cent from50grams to90gramsa day,and fat increases about four-fold from35grams to140grams.The total amount of carbohydrate is much the same irrespective of wealth,except that it is somewhat lower in both the very poorest and very wealthiest countries.In the very poorest,people just havetoo little of everything.In the very wealthiest countries,consumption of foods rich in protein and fat is high enough to cause asmall reduction of foods rich incarbohydrate.
But more interesting than the general similarity in total carbohydrateis the very considerable change in the sorts ofcarbohydrate as you pass from poor to rich countries.There is a great increasein the amount of sugar,and a corresponding fall in theremaining carbohydrate,mostly starch,This is similar to the situation whena particular country becomes increasingly wealthy:more sugaris eaten-and less bread,rice,corn,potatoes or other starchy food.The figures I have given so far are averages for whole populations.When I tell an audience in London that they eat5ounces ofsugar a day,they profess astonished disbelief,Everyone insists thatthey eat much less than this,so I usually say that since5ounces isthe daily average there must be other people who are eating more.A frequent criticism of the experiments (to be described later)carried out in Queen Elizabeth College Nutrition Department isthat
we use excessively large amounts of sugar;the apparent ill-effects produced would not,it is said,be caused by the amounts thatordinary people consume.After all,it is argued,immoderatequantities of any food might be harmful.When we first reported that sugar in the diet increases the amounts of the fatty substances in the blood(notably triglyceride and cholesterol),an American scientist wrote that sugar produces no increase in triglyceride if the amountstaken”are of the same order of magnitude as the average sugar intakeof the American population'.Similarly,another researcher claimed that "there is little relationship under ordinary conditions between dietary sugar and plasma cholesterol”.These references to "average” and“ordinaryconditions” assume that virtually everybody takes an amount of sugar that is little different from the average intake,which inAmerica and in theUK is about125grams a day.This isabout as sensible as saying that everyone takes about an averageamount of alcohol,so that alcohol cannot be a cause of livercirrhosis.
Though there is little published information about sugar consumption in individuals,common experience tells us that it varies a great deal.There are people who take no sugar in their tea or coffee,rarely if ever take sweetened drinks,eat little confectionery and do not ordinarily eat desserts.There are others who begin the day with sweetened cereal and added sugar,have sugar in all their hot beverages,eat sizeable quantities of confectionery,cakes and biscuits between meals,and always have a cooked and heavilysweetened dessert with their main meals.The meagre figureson individual sugar intake that have been published confirm thatthere is a considerable range.In ourQueenElizabethCollege studies,we measured how much sugar was being taken by various groupsof older children and by men and women of different ages.Theyare not necessarily representative,but I give you our results in thetable below because they demonstrate some general features.Let me add that it is likely that we are underestimating theexact consumption,because people tend to forget the occasionalsugar drink or piece of chocolate they have been taking.Still,one canget some interesting information even if it is somewhatapproximate.
The most striking feature is the very high consumption byteenage boys;more than50per cent above that by teenage girls.The sexdifference persists throughout later life although not so strikingly.From the age of20,men take something like IS or20per cent moresugar than do women.This is possibly because women are moreweight-conscious,so they deliberately-and wisely-restrict theirsugar consumption.A decline of sugar intake sets in withincreasing age,so that people in their sixties take about one third lesssugar than do people in theirtwenties.These figures come from our own studies inLondon,but Ihave also tried to find statistics reported by others.Mostly,however,these cover only some sugaritems.A study of over1,000American boys and girls aged between14and18in the state ofIowa showed an average sugarconsumption by the boys of389grams a day and by the girls of276grams.This amounts to an average of more than40per cent of their totalcalories as sugar;the average of the whole population in the U SA wassomething like18per cent.In a study of17-year-old white childreninSouth Africa,sugar consumption was not as high,yet one thirdof the boys took an average of241grams and one third of the girlsan average of171grams.
InScotland,dentists examined13-year-old boys and girls,a younger age-group than any we have studied.They estimatedonly the amount of confectionery the children ate,and they addedthat they were sure that their figures were in fact underestimates.The average weekly intake was I71/2ounces,boys eating slightlymore than girls.Eight per cent of the children,however,took more than32ounces aweek.
These figures are equivalent to a daily intake of about2ounces(55grams)a day of sugar from confectionery for all thechildren,and nearly4ounces (105grams)for8per cent of the children.The average intake of confectionery for the whole British population is8ounces a week,which is matched only bySwitzerland.According to figures published by the British confectionery industry,consumption in children under16is about17ounces a week,roughlythe same as that reported by the Scottishdentists.As well as confectionery,of course,teenagers undoubtedlyeat more than adults do of such items as cakes,biscuits,ice cream and desserts.Even at a conservative estimate,these can be expected to bring the total amount of sugar to something like50per cent more than the national average.This would make W1e totalconsumption of a I3-year-old about71/2ounces of sugar a day,which would supply850calories out of their daily total intake of about3,000calories.Now think of the children who eat not171/2ounces of sweets aweek but more than32ounces,and it is pretty certain that there must bea lot of children getting at least half of their calories from sugar.You might perhaps think that,eating a lot of sugar betweenmeals,they would cut down the sugar in meals.Not at all.Acolleague of mine found that the midday dinners in several Englishschools contained sugar giving about25per cent of the calories,and onthe whole children get the same sort of food at school as at home.Soit does look as if children get more than the average amount ofsugar,sometimes much more;not only in the snacks and drinksbetween meals,but also in the meals themselves.Part of this,I am sure,is ·due to the attitudes of their parents,who wish to give pleasureto their children,to win their affection,and to provide them,asthey believe,with the energy they need for growth and work and play.The London Times reported the case of a young lad eatingmore than6Yz pounds of sugar a week,which amounts to nearly350pounds in a year.His dentist complained that6months after hismouth had been made quite free fromdecay; it was now oncemore full of rotting teeth.Our own record comes from a15-year-oldboy who also consumed just under a pound of sugar a day,or around1,700calories from sugaralone.Of course,just as there are some people who eat very muchmore than the average amount of sugar,there must be those who eatless than the average.Our own figures suggest that the range ofvariation of sugar intake is far greater than the range for most other foods.We have found people taking as little as half an ounce a day (15grams)as well as those taking as much as14ounces a day (400grams);the latter are eating in one day what the former eat in a month.Altogether,I find it difficult to resist the conclusion that,whereas the national average consumption of sugar in the US and the UK represents something like17per cent or18per cent of the average calorie intake,the average for children would work out at around25per cent of the calories or even a little more.And again let me say that there must be some who are getting50per cent of their calories from sugar.In absolute terms sugar consumption for many children must amount to nearer10ounces a day than the5-ounce nationalaverage.In case you think that I am exaggerating the amount of sugar taken by children,let me quote from an advertisement by Sugar Information,the publicrelations organization for theAmerican sugar industry.Forget for now the referenceto obesity.I shallbe saying something more about this aspect of sugar later.Here is part of theadvertisement:
You’ve probably had people tell you they're avoiding this or that because it has sugar in it.If you want tosee how much sense there is to that idea,next time you passa bunch of kids,take a look.Kids eat and drinkmore things made with sugar than anybody.But howmany fat ones do yousee?
Good nutrition comes from a balanced diet.One that provides the right amounts,and right kinds,of proteins,vitamins,minerals,fats and carbohydrates.Sugar isan important carbohydrate.In moderation,sugar has aplace in a balanced diet.
The word I like best in this advertisement is "moderation”.But would you really accept as moderate the current average consumption of sugar by kids,probably amounting to25per cent or more of their calories and adding up to7ounces or so a day?Let me pursue this concept of moderation,about which webear so often.Supposing we were living a couple of hundred years ago.People inAmerica andBritain were then eating on average acouple of ounces of sugar a week.If someone were then to have saidthat you should eat sugar in moderation,you would have thoughtinterims of perhaps no more than3ounces a week.You wouldcertainly have protested that7ounces a week-an ounce a day-was aquite excessive amount.But people today accept five ounces a day asmoderate;only when someone eats much more than this does itbecome generally accepted that they are eatingimmoderately.Look now at babies,who are bottle-fed more and more,even though there is a slight drift back to breast feeding in some middleclass homes.A common feeding formula consists of dried cow's milk,perhaps modified in some way,with added sugar.Except in some sensible preparations,the sugar that is added is sucrose,not lactose (milk sugar),and I shall show later that this is not at all the same in its effect on the baby.Here I refer only to the disadvantage of sugar having a much sweeter taste than lactose,so that a baby is inducted into his later sugar-rich life by being encouraged todevelop a taste for maximumsweetness.As soon as a baby begins to receive mixed feeding-and thisis often at two or three months or even earlier-cereal will beadded to the diet,and then foods like egg yolk and minced meat andsieved vegetables and fruit.Many mothers will add sugar to the cerealand,to the fruit,although it is by no means uncommon to add it alsoto egg and meat and fish.And I have not mentioned thepernicious habit of giving babies dummies that have a reservoir for syrupor which from time to time are dipped into the sugar bowl.I knew of a family of four people:father,mother,a girl of4anda baby of six months.They buy and use1I pounds of sugar aweek,and this does not prevent them from also buying the usualassortment of biscuits and ice creams and other manufactured foodsand drinks with sugar.The baby certainly gets less than a quarter ofall this,but it is hardly deprived since its dummy is dipped intothe family sugarbowl.
One of the reasons why some people find it difficult to acceptthat on average Americans and Britons eat about two pounds of sugara week is because they think only of the sugar that is brought intothe home as visible sugar.But an increasing proportion of sugar isnow bought already made up into foods.If you look at your ownsugar consumption,the chances are that over the years a smallerand smaller fraction will be household sugar and a greater andgreater fraction industrial sugar.Household sugar is mostly what isbought by the housewife,but also includes the much smaller quantity used in cafes and restaurants.Industrial sugar goes to the factory and comes to us in the form of confectionery,ice cream,softdrinks,cakes,biscuits,and nowadays also a very wide range of otheritems,especially the fancily packaged "convenience foods'.The poorer countries,as you might expect,consume less of their sugar in the industrial form;manufactured foods are a luxury consumed increasingly in the wealthier countries.In the latefifties,according to the FA0report I mentioned earlier,South Africa took only20per cent of its sugar in manufactured foods,while France Took40per cent and Australia55per cent.American manufactured sugar increased from less than30per cent in1927to about50percent in1957,and is now more than70per cent.The increase in the proportion of manufactured sugar in theUSA is especially interesting in view of the fact that the total sugar consumption there has not changed much over thisperiod
.Between1974and1983the use of High Fructose Syrup Increased from3to43pounds a head;almost all of this was used in food manufacture as an alternative to sugar.If this is taken into the calculation,industrial use of sugar in1983was74%and domestic use26%.
TheUK use of manufactured sugar amounts to about65percent.The ways in which sugar is used by food manufacturers in theUK,and the various amounts involved,are shown in the table onp.46.But I want to amplify these figures in several ways.To begin with,I believe there are several reasons why Westerners continue to increase their consumption of manufactured foods containing sugar.One is that any efficient manufacturer is constantly producing47more and more attractive foods.Because of competition,he keeps making new products or new variations on his old products,each time with the purpose of producing something that is even more attractive than before.More and more,people find it difficult to resist these delicious foods and drinks.In1981,nearly£1oo million was spent on advertising sugar-rich foods;£53million of this was spent on advertising chocolate andconfectionery.Secondly,sugar,as we have seen,offers many more properties than just sweetness.Its use in different sorts ofconfectionery depends also on its bulk,on its ability to exist either incrystallized or non-crystallized form,on its solubility in water and on itschange of colour and flavour when heated.Its use inlams depends onits ability to set in the presence of pectin,and on its highosmotic pressure,which inhibits the growth of moulds and bacteria.Insmall quantities,sugar seems to enhance the flavour of other foodswithout necessarily adding specifically to sweetness.These and manyother properties of sugar amount to an extraordinary versatility,and account for its use in such a vast range of foods and drinks.The result is plain to see if you walk around thesupermarkets and make a list of foods with sugar among their ingredients.Leavingaside obvious items like cakes,biscuits,desserts and softdrinks,you will find sugar in almost every variety of canned soups,incans of baked beans and pastas,many kinds of canned meat,almostevery breakfast food,several frozen vegetables and made-up dishes,and most canned vegetables.In some of these foods,especially inthe foods like meats or vegetarian meat substitutes,the amounts ofsugar are quite small.But in many others the amount is really surprisingly ·high.You can get some idea by seeing where sugar ranks in thelist of ingredients.If it is first in the list,the food contains moresugar than any other ingredient.When I tried this exercise,this was true of one or two canned soups,one or two breakfast foods and several pickles andsauces.A third reason why people increasingly buy manufactured foods containing sugar is that they prefer to buy foods in "convenient form-usually items that they would previously have made for themselves.And it looks from my sampling as if these foods are likelyto contain more sugar than they would have done when made athome.The manufacturer seems to have found,or at any rate convinced himself,that people like sugar with everything,and more and more of it.In the last two or three years I have found it difficult at a bar to get tomato juice-my favourite tipple-that has not had sugar added to it.I am also rather fond of peanut butter,but the manufacturersof the two most popular brands inEngland have now decided that I ought to have it with sugar.Here let me give one good mark to the health food people;at least some do not put sugar into the peanut butter-anyway,notyet.If you want to test what I am saying,try next time you are out to get a drink of something or other that is non-alcoholic,does not contain sugar and is not specially advertised as a "diet drink'.It does seem to be true that until they reach a certain limitmost people demand more and more sugar as they go on taking it.Certainly the converse is true.Many people have been restrictingsugar for some time,either because they are concerned about theirweight or for even more serious reasons;.now,when for social reasonsthey do have to take sugary foods and drinks,they often find themintolerably sweet.On his third birthday,my well-brought-up grandson Benjamin took one bite of his iced birthday cake and ate no more because,he said, "It's toosweet.What is surprising to me is the high proportion of sugar in many so-called health foods besides the peanut butter I have mentioned.Sugar appears to figure prominently in foods that are supposed to be "good for you'.Eggs and bacon,or the old British favourite skipper,would be better for you than several of the special breakfast healthy foods such as many brands ofmuesli.One more reason why Westerners eat so much sugar is that increasing affluence gives people more leisure,creating the kind of situation-sitting in front of the television,making a trip in the carthay is conducive to the consumption of snacks and soft drinks,so easily available nowadays,and considered to be inexpensive.And Snacks usually,and soft drinks almost always,are rich sources ofsugar.Another point about soft drinks.When I was young,if I was thirsty I had a glass of water.Nowadays when children are thirsty it seems almost obligatory that they quench their thirst with some sugar-laden cola or other drink.And this is often true for adultstoo,although it is just as likely to be an alcoholic drink like beer.In this way,sugar is consumed almost inadvertently.The modem trend of using drinks like tonic water or bitter lemon as mixers is for many people a further source of sugar of which they are hardly aware.Two small bottles with your gin or vodka and you haveswallowed an ounce or more ofsugar.Life is difficult for people who,like myself,want to avoid sugar,49and particularly for those who,like the people with hereditaryfructose intolerance,get sick when they take sugar.But I am glad to see that an increasing number of manufacturers put no sugar into some of their products,and that you can find more and more labels marked "sugar-free'or "no added sugar'.In particular it is encouraging to see more baby foods labelled in this way.Words mean what you want them to mean
It is very confusing when people use different words for the same thing.InEngland,we say "lift”for what the Americans call "elevator”, "property'when they say "real estate',and "petrol”when they say "gas”.But even greater misunderstandings arise when people use the same word for different things.The American Woman carries a handbag which she sometimes calls herpurse,while an English woman carries a handbag in which she has a much smaller purse for her money.The American woman carries her money in herwallet.As we saw in Chapter3, "sugar'sometimes means the beautiful white powder or lumps that this book is all about-sucrose-but sometimes it means a different substance that circulates in the blood-glucose.Another example is the word "energy',which,as I Shall discuss,means one thing to the non-scientist and quite another to thenutritionist.Glucose is a sugar that is found,usually with other sugars,in some fruits and vegetables.It is very important tobiochemists,physiologists and nutritionists because it is a key material in the metabolism of all plants and animals.Many of our principal foods are sooner or later converted into glucose,and glucose forms one of the most important substances that is metabolized (or oxidized or burned)in the tissues to supply energy for everyday activities.
9.1Where energy comes from
Almost every book written by people in or associated with the sugar industry contains a section in which you are told how important sugar is because it is an essential component of the51body.They tell you that it is oxidized so as to give energy,that it is a key material in all sorts of metabolic processes,and so on.And They imply or even say explicitly that all this is to do with "sugar'(sucrose),whereas in fact they have been talking about "blood sugar'(glucose).The fact is that sucrose and glucose have different chemical structures and their effects in the body differ in important ways.When the word "sugar'is used at one moment to mean the sucrose in your food and at another to mean the glucose in your blood,these differences are hidden.So accustomed do we then become to this blurring of definitions that eventually we find it difficult to accept the vital differences between the sucrose we eat and the glucose in ourblood.There is a second way in which you may be led to believe that sugar is an important,if not essential,item of our diet.Here is a quotation from a pamphlet from the sugar industry: "Sugar works for you with each bite you eat-for your body is an energy factory with sugar as its fuel.'Firstly,it is not "sugar' (sucrose)but "sugar'(glucose)that is the body's fuel,and secondly,what does "energy really mean?When you say, "I have no energy',or "Little Johnny is full of energy',you use the word to mean either physical activity or the inclination to be physically active.When you say that Johnny is full of energy,you picture him rushing around,leaping up and downstairs,climbing a tree or tearing along on his bicycle.On the other hand,when you say you have no energy you imply that you do not want to do anything much other than sit about,or preferably liedown.So when someone says, "Sugar gives you energy",you imagine that this is just what you need to leap out of your chair and dash round like little Johnny.But the physiologist and the nutritionist who talk about sugar and energy mean something different.What they mean is that sugar (like any other food,after having been digested and absorbed)can be utilized by the body so as to release the energy you need for all the functions of the body.These include such automatic activities as breathing,heart-beat or digestion,and all the chemical reactions of the living body that add up to what is called "metabolism”.They also include such voluntary activities as dressing or walking orrunning.What people really mean when they say that sugar gives them energy is simply that it is a potential source of the energy needed for the processes of living.It is there when you need it,in the same sort of way as the petrol (or gas!)that you put into your car is in the tank,ready to be burned when you want the car engine to go.Just putting another gallon or two in the tank does not,of itself,make the car go any faster or make it any more energetic.And taking another spoonful of sugar does not,of itself,make you jump out of your chair and rush to mow thelawn.All food then contains "energy',in that some of its components can provide the fuel for the body's workings.Normally you have quite a sizeable reserve of this fuel in your tissues,stored from the food you have eaten on previous occasions.If you were starving,so that you had little or none of this reserve,and if in addition it were imperative that you have some fuel in your tissues within minutes,in addition to the glucose in your blood,then it might be a good idea to eat sugar rather than any other food because the sugar quickly gets digested and absorbed and taken to the tissues.A piece of bread and butter would take a few minutes longer.This insignificant time differential is what the sugar propagandists mean when they talk about sugar's "quick'energy.But isn't it really quite rare for circumstances to arise that make it imperative for you to take advantage of this more rapid availability of "energy'from sugar?And besides,as we shall see later,it may be that the rapidity with which sugar floods the bloodstream is harmful rather than beneficial.I sometimes wonder whether the insistence that sugar contains energy arises from the fact that it contains nothing else.All other foods contain energy as well as at least some nutrients in the way of protein or minerals or vitamins or a mixture of these.Sugar contains energy,and that is all.
9.2Pure is good
As I have shown,the combination of all foods contain the whole range of essential materials that the body needs for its survival and well-being.Each one of these is derived from living plants or living animals;if they are not processed in any way,they contain a mixture of approximately50essential materials.From a cabbage,you obtain amongst other essentials some vitamin A and vitamin C and calcium.From a piece of meat you obtainprotein,fat,several vitamins of the B group,iron,and many other nutrients.But suppose one were to cultivate pine trees instead ofcabbages,and then extract the vitamin C and eat that instead of eatingcabbage?It would be possible now to claim that you have consumed53absolutely pure vitamin C,but it would not be of any particular advantage to get it this way rather than from the cabbage.In fact you would lose out in this transaction because the cabbage would have given you other nutritional benefits apart from vitamin C.Yet this is really the sort of thing people do when they make sugar.They plant vast areas of land with sugar cane or sugar beets instead of crops that they can eat more or less whole.Then they take the cane or beet and extract,clean,filter,refine and purify it until they have something that is virtually100per cent sugar.At this point,the refiners say with absolute truth that this sugar is one of the purest foodsknown.Once more a word is being used in two different senses.When You say water is pure,or bread,or butter,you mean that it is not contaminated with anything inferior,and especially not contaminated with anything harmful.But then you are persuaded to carryover this sense of wholesomeness to the chemists'meaning:a material that does not have something else mixed with it,irrespective of whether this something would have been harmful or harmless or evenbeneficial.There is no special reason to praise sugar for the fact that,in the course of its elaborate preparation,it is freed from all other materials so that it is chemically "pure',as are most of the other materials the chemist has on his laboratory shelves.Equally I would see no reason for being pleased at being presented with pure protein for myconsumption,or pure vitamin Bu )or any other dietary component in its isolated state.What virtue would this represent?
10.Sugar's Calories make you think they say
The inclusion of large amounts of sugar can affect our diet in two ways.It can be taken in addition to the normal diet,or instead of a calorie equivalent in some other food.More likely than either of these alone,it can be done both ways:by adding something to the total calories,and also displacing some other foods.Since,as I showed,sugar supplies nearly one fifth of the average eater's calories,no aspect of sugar consumption can be ignored.Its effects will be particularly evident in those many people whose intake of sugar is appreciably greater than the average.The consumption of sugar on top of an ordinary diet increases the risk of obesity;the consumption of sugar instead of part of an adequate diet increases the risk of nutritional deficiencies.In this chapter,I want to deal with the question of sugar consumption leading to an increase in calorie intake.I have already pointed out that the average intake of sugar inAmerica orBritain supplies some500to550calories a day.But this is not the whole picture.Many people take at least twice as much as the average of4V2or5ounces a day;they are getting at least1,000calories a day from sugar,and1,500calories or even more is not unknown.This sounds enormous,but I am not counting visible sugar alone.Such people consume only part of this daily quota as sugar by itself.Moreover,much is taken with other foods that supply lots of calories:cocoa in chocolate,fat in ice cream,fat and flour in biscuits and cakes.This adds up to even more calories than the figures I have just given.This book is not about obesity and its causes and treatment,so I shall mention only two matters that are particularly relevant to the55question of sugar-one obvious,one less obvious and only recently properly investigated.The obvious one is that people take sweet foods and drinks because they like them.And just as you will eat less than you need if your food is unpalatable and unappetizing,so you will eat more than you need if it is especially appetizing.Let me remind you of some of the points I made in Chapter2.Most often,people eat chocolate or cake because they are tempted by their appearance and taste,and not because they really need those extra calories.And when people take sugary soft drinks,they usually do so because they are thirsty rather than because they are hungry,even though the drinks supply lots of calories (probably not needed)along with the water that is needed.Thus,people often eat and drink to satisfy appetite-for pleasure,rather than to satisfy hunger.It is worth spending a moment or two more on this distinction between appetite and hunger.What are the foods that make overweight people overeat?Mostly,people don't become overweight because they eat too much meat or fish,or too many eggs,or too much fruit or vegetables.It is almost always that they eat too much bread,or sweets and chocolates,or cakes and biscuits,or because they drink too many sugary cups of tea or soft drinks.Or,of course,it may be because they drink too much beer or other alcoholic drink.Now just think.When people put sugar in their tea or coffee,is it because they are hungry and need the extra calories?Or is it that they prefer the beverage sweet?If it were really a question of caloric needs,then they would be adding the sugar only when they were hungry or take someone who goes to the pub after his supper and drinks two or three pints of beer with his friends.Is this because he is short of calories?Does he go to the pub only when he is hungry?Or does he drink just half a pint during the evening when he has had a particularly large meal at home?And what about the woman who sits in front of the television after supper,with a box of chocolates on her lap.Does she eat only one chocolate because she had a large dinner that night,compared with the half-box of chocolates she ate the previous night when she was really hungry?The fact is that on both occasions she nibbles chocolates because she likes them,and this has nothing whatever to do with her hunger.In general,people take sugar or sugary foods or drinks or alcohol for pleasure.The calories they inevitably get at the same time are quite incidental and have nothing to do with the satisfaction they get from consuming these items.When you come to think of it,almost all of the tempting foods that are taken to satisfy appetite rather than hunger contain carbohydrate that is either sugar or starch,or they contain alcohol.This was confirmed when my colleague Diane Adie and I carried out a survey among more than1,400women who were members of Slimming Magazine's Slimming Club.We asked them to tell us which of along list of foods they had found difficult to resist when they were overweight.Twenty-five per cent put cakes and biscuits at the top of the list,and a total of72per cent named carbohydrate-rich foods as their main temptation.Sixty-four per cent of the listed foods contained added refined sugar,while,of the other16foods mentioned,none scored more than4per cent.These carbohydrate-rich foods,by the way,have another characteristic;they are all artificial foods that do not exist in nature in the form in which we eat them.As I have ·said elsewhere,people are not likely to get fat if they make up their diet mostly from the foods that were available to our prehistoric ancestors,like meat,fish,eggs,fruit and vegetables,while as far as possible avoiding manufactured foods,most of which are carbohydrate-rich.The fact is that,given the choice,people eat the foods that they like,and the more they like them the more they are likely to eat them.You may think this so obvious that it is unnecessary to say It,but this simple fact accounts for most obesity.If you find that difficult to accept because of lack of proof,let me recall a story in Bernard Shaw's The Adventures of the Black Girl in Her Search for God.In her wandering the girl comes across a scientist,clearly meant to be Pavlov,who is experimenting with a dog.When asked what he is doing,he says he has discovered that,when he shows the dog a piece of meat,the dog salivates. "But everybody knows that,'says the black girl" Maybe,answers the scientist. "But until I did the experiment,it wasn't scientifically established.”So what about establishing scientifically that the availability of very attractive foods causes obesity?During the last few years,research workers have discovered that the simplest way of producing a fat rat is not to offer it only the simple pellets that make up the very nutritious food normally given to rats,but to let it also have a go at eating cakes,biscuits,chocolates and so on.Rats eat this sort of food with enthusiasm,and a very effective fattening diet it turns out to be.So it is now supported by experiment that such highly attractive foods promote overeating and obesity.When you come to think of it,the fact that a low-carbohydrate diet is an effective way of losing excessive weight also suggests that obesity is caused by eating the irresistible high-carbohydrate foods.The low-carbohydrate diet severely limits just those foods that,as we saw,people find most tempting,while allowing you to eat as much as you like of foods such as meat and fish and vegetables.You lose weight because these last are foods the body needs to satisfy hunger,and not just to satisfy appetite,so you stop eating when you have had enough.This is not to say that these foods are in the slightest degree unappetizing;they do not,however,encourage overeating.It should also be remembered that low-carbohydrate foods are the ones that happen to contain a high concentration of the nutrients that the body needs.Now let me try and explain why there are some people who consume quite a lot of sugar but are not overweight.There are three reasons why this can happen.The first would apply to those whose sugar intake is matched by a corresponding reduction in other foods,so that they are not taking excessive calories,although,as I shall show,they may be running the risk of nutritional deficiency.The second reason may be that they are extremely active people,so that they take a lot of calories but also use them up.The third possible reason why people might eat a lot of sugar and still not put on weight is controversial.There is now evidence that some lucky people's bodies have the facility of burning off surplus calories;sometimes this increase in metabolism is just the equivalent of the extra calories they take,and so they do not put on weight.This view is not universally accepted in the textbooks of physiology and nutrition,but I find the evidence is now quite convincing.Even these people,of course,have a limit to the number of surplus calories they can dispose of in this way;they too will put on weight if their intake of calories is in excess of disposal.If you are one of the lucky ones who can get rid of excessive calories from sugar,you may not get fat,but by no means will you escape its other ill-effects.Tooth decay,indigestion,diabetes,coronary thrombosis and all the other conditions I shall discuss-these are not necessarily avoided by people who can eat lots of sugar without getting fat.So there is no point in worrying whether or not everyone agrees that metabolism can increase in response to an increase of food consumption.Let us just say that you cannot help getting fat if you are taking in more calories than you can dispose of-and a very obvious and potent source of excessive calories is the consumption of foods and drinks that contain sugar,largely because people find them so delicious.It may be that you are one of those who finds it difficult to accept that sugar can be an important factor in producing obesity.InAmerica,especially,an intensive advertising and public relations campaign has been in progress for several years to convince the public that sugar has nothing to do with getting fat.First you are told that a spoon of sugar contains only18calories.The advertisements are: "Sugar's got what it takes.Only18calories to the teaspoon.And It’s all ENERGY”.This is quite true,provided you use a rather small spoon and make sure it is a level spoonful rather than the more usual heaped spoonful.Our research experience shows that most people take the sort of spoonful that gives them more like30calories than18calories.You might want to work out how much sugar you take just in tea and coffee.Suppose you take an average number of cups,which is about six a day.Suppose you take the not ridiculously large amount of two spoons a cup,each giving "only”25calories.That is50calories a cup,and300calories at the end of the day.This is the whole truth is likely to be,rather than the partial and misleading truth about18calories a spoon.There is also a second point.The sugar people tell you not only that sugar does not make you fat;they say it actually helps to make you slim.Their argument goes like this.People get hungry because they have a low level of glucose in the blood.If you eat sugar,you stop being hungry because it is very rapidly digested and absorbed,so that the level of glucose in the blood rises.Have a little sugar from time to time,then,and you will end up eating less,and so reduce your weight.Here is a quote froma sugar industry advertisement:
Willpower fans,the search is over!
and guess where it's at?In sugar!
Sugar works faster than any other food to turn your appetite downturn energy up.
Spoil your appetite with sugar,and you could come up with willpower.
Sugar-only18calories per teaspoon,and it's all energy.’
Unfortunately,there are three flaws in this argument.The first is the idea that your eating is controlled by the level of your blood sugar.This theory has now largely been discarded.There is quite a lot of evidence that it is not correct,and certainly that it is not a complete explanation of what controls hunger.Second,there is no reason to believe that,just because it is absorbed quickly,sugar will affect your appetite any more than any other food will.Third,there is absolutely no evidence at all that the sugar reduces your hunger to an extent greater than the calories you have derived from it.Suppose you have just taken two spoons of sugar in each of two cups of coffee,and thus gained100calories.You are now less hungry,so you eat less.But by how much?A hundred calories?Fifty calories?Three hundred calories?The only evidence I know of suggests that your appetite is reduced by less than the calories you have taken from the sugar.This evidence came from some tests I carried out some years ago,when the same "lose weight by eating more'story was being noised about,though in relation not to ordinary sugar(sucrose)but to glucose.The idea was that you took about one third of an ounce of glucose three times a day,a little while before each meal.Then you followed a calorie-restricted diet,and you were supposed to be able to do this more easily because the glucose had reduced your hunger.What I did was to take two groups of overweight people and put them on the same calorie-reduced diet (one in fact designed by the manufacturers of the glucose tablets)with or without the additional glucose.At the end of six weeks,people taking the glucose had indeed lost weight,a matter of6%pounds.But the people on the same diet without the glucose had lost about11/2pounds “nearly5pounds more,or close to twice as much.You might think then that the glucose did nothing at all-that the people who consumed it at the same amount of their diet as the others,but lost less because of the extra calories from the glucose.But in fact this would only account for about one pound of the difference,not the5pounds or so that we found.The only explanation seems to be that the glucose tablets actually increased the amount that people ate on their calorie restricted diet-exactly the opposite of what it was supposed to do.I suppose it is natural for the vast and powerful sugar interests to seek to protect themselves,since in the wealthier countries sugar makes a greater contribution to our diets,measured in calories,than does meat or bread or any other single commodity.But what is always sad is to see scientists being persuaded to support the sorts of Claims I have just described.Is it because they like sugar just as much as other people do?Or is it because at least some of them have still not got around to accepting the idea that all carbohydrates don't behave in the same way in the body?Or is it that they have persuaded themselves that the modern scourge is too much fat in the diet and so they have difficulty in admitting that they may have been wrong?Equally,it is difficult to see why any nutritionist should endorse the consumption of sugar at the present level.What with the high prevalence of obesity,there is no acceptable reason for recommending that sugar intake should not be reduced,or that it should be reduced only as part of a general reduction of food.It is after all the only food that supplies nothing whatever in the way of nutrients;it is,remember,the claim of the sugar refiners themselves that their product is virtually100per cent pure.It supplies nothing whatever other than calories,and calories are all that matter in weight reduction.Cutting down any other food-any other food-is bound to reduce nutrients as well as calories.There is no evidence that overweight,people are taking an excess of nutrients;but there is quite a lot of evidence to suggest that some of them could do with a nutritionally better-balanced diet.I shall have more to say about this question of calories and nutrients in the next chapter.The proof of the pudding is in the eating-or in this case in the not eating.Many people lose excessive weight very successfully simply by giving up sugar,or by severely restricting it.If you take only one spoon of sugar in each cup of tea or coffee,and you drink only five cups a day,you might lose ten pounds of weight in a year,just by eliminating the sugar in your coffee or tea.Sometimes,in order to reduce their weight to acceptable levels,people also need to restrict starchy foods,and so adopt a strict low carbohydrate diet.Of course,giving up sugary and starchy foods and sugary drinks requires some self-discipline,as does any alteration in dietary habits.But for several reasons,described in detail in my earlier book This Slimming Business,the low-carbohydrate diet is the most sensible and effective way of controlling body weight.And my colleagues and I have demonstrated by experiment,not simply by armchair calculation,that this kind of diet gives a far better supply of nutrients than is made available under the orthodox regime that involves eating the same foods as before,only less.I have never really understood why so many doctors in the American medical and nutritional establishments have frowned upon a diet that tells you in effect to reduce only,or chiefly,those foods that give you the calories you don't need whilst giving you little of the nutrients you do need.Although I said I was not going to go into details about the principles of obesity,I must add one important point about babies.I have already mentioned the custom,increasingly common among parents,of adding sugar to milk formulas and to the cereal and other foods on which babies are weaned,as well as giving them sugary drinks.The result is the number of fat babies to be seen everywhere,to the extent that paediatric authorities in theUnited States and theUnited Kingdom have frequently drawn attention to the problem.A few years ago it was suggested that the overfeeding of babies not only made them fat,but encouraged the development and persistence of obesity when they became adults.The story was that the fat cells in the babies'adipose tissue are encouraged by overeating to divide,so that not only do the existing cells become full of fat but the body produces more cells in order to accommodate still more fat.This idea was based on the finding that the number of cells that could be seen in the adipose tissue of fat babies was greater than the number in thin babies.These extra cells persist into adulthood,so that the fat baby becomes an adult with more adipose tissue and hence a greater propensity to store fat.Such a person,it was concluded,would clearly have a greater problem in controlling excessive weight than one with a normal amount of adipose tissue.More recently this suggestion has been challenged on the grounds that it depends on the ability to count accurately the number of cells in the adipose tissue.The critics say that in thin babies some of the cells are empty and can easily be missed when they are counted;in a fat baby the cells all contain fat and are therefore more visible and likely to be counted.This leads to what the critics believe is the mistaken conclusion that there are fewer fat cells in thin babies than in fat babies.Whatever the truth about fat-cell numbers,what is certain is that babies,like older children and adults,get fat if they take in more calories than they use.And you have only to look around you to see how easy it is for a baby to get these excessive calories.Even though some manufacturers of baby foods have stopped putting sugar in their products,mothers will do so with little hesitation.Nor do they hesitate to give their babies sugary drinks in their bottles whenever they believe that the little ones are thirsty.
.How to eat more calories without eating real food
A criticism that one hears frequently of refined sugar is that it supplies "empty calories'.This is true.Often,the critics go on to say that the refining process is at fault in that it removes essential nutrients that are present in unrefined sugar insignificant amounts.This is largely not true,as we have seen.Having considered what happens when you take sugar in addition to your other foods;let us now look at what happens when you take it instead of some of your other foods.After all,if people take500calories a day as sugar,and sometimes much more,it is likely that there will be some reduction in other foods;there must be a limit to how much even the most gluttonous person can eat.In the simplest situation,imagine a diet of2,500calories a day,made up largely of good nutritious foods like meat and cheese and milk and fish and fruit and vegetables,with some potatoes and bread and breakfast cereal.Now keep the calories at2,500but replace500or550of them by sugar,the average amount taken in a day.I have shown that you can usually do this simply by adding only moderate amounts of white sugar to your tea and coffee,and taking an occasional sugar-sweetened soft drink.Clearly,the result of this replacement of20per cent of your calories by sugar would be a reduction in your intake of nutrients-protein,all vitamins,all mineral elements-also by20percent.No nutritional deficiency will occur if your previous diet contained an excess of20percent of all the nutrients you required.But Suppose it did not contain this surplus.More important,suppose that you were one of those who takes more than the average amount of sugar-equal perhaps to30per cent of your calories,or even40percent.Now it begins to be more difficult,as you can see,to imagine that the diet of2,500calories which originally supplied as much of the nutrients as you needed will still do so when the foods containing them are replaced by30per cent or40per cent of nutrient-free food.This does not mean that by eating41lb or5ounces of sugar a day-or even7or8ounces-you would be rapidly heading for pellagra,beri-beri or scurvy.In extreme cases,with quite a lot of sugar and with the remainder of the diet not too well constructed,such diseases do occasionally occur.I shall later refer to the role of sugar in producing full-fledged protein deficiency in poor countries.But it may very well occur that your diet is marginally insufficient in nutritional terms,so that you are in that twilight zone between excellent health and a manifest deficiency disease:not quite well;tired and easily exhausted;prone to aches and pains and odd infections.All these vague but very real symptoms occur in all of us at some time or another.But while being a bit under par is no proof that your diet is deficient,this must be considered as a possible cause in people whose diets are unbalanced by a large intake of sugar.Is there any way of showing that sugar can really-not just hypothetically-push more desirable foods out of the diet?One way of finding this out,I thought,was to check the trends of consumption of different sorts of food,especially those that are universally recognized as highly nutritious-meat,milk,fish,fruit and eggs.In particular I decided to look at the trends for meat,for two reasons.First,it falls into the category of highly nutritious foods,andsecond,for most people it is also highly palatable.I argued that the increase in the consumption of sugar-containing foods,because they too are very palatable,might be accompanied by a reduction in the consumption of meat.
I must break off to explain why,when you look at the relevant statistics,you have to bear in mind two important considerations.The first is that,although total sugar consumption inAmerica stopped rising some30or40years ago,and inBritain in the last12to15years,there was a simultaneous decline in the use of sugar in the home and an increase in the amount of sugar used in manufactured food.Crudely,and not completely accurately,one can say that people are putting less sugar in beverages at home but take more sugar in ice cream and cakes and biscuits,where,incidentally,it comes with plenty of other calories but not much in the way of nutrients.Youwould then expect the effects of sugar in pushing other foods out of64the diet to be increasing,even though the absolute amount of the sugar itself is notincreasing.The second point to bear in mind is that the foods Imentioned,besides being amongst the nutritionist's favourites,are also relatively expensive,so that more of them tended to be consumed by wealthy people than by poorer people.This social gradient has declined in the Western world with increasing affluence;the poorer sections of the population are not as poor as they used to be.So what nutritionists and economists have been predicting is that general increasing affluence would bring about an increasing consumption of meat,milk,fish,eggs and fruit.One would expect little or no change in consumption by the wealthier groups of thepopulation,who presumably were always able to eat as much of these desirable foods as they wished;on the other hand,one would expect a great rise in the amounts that poorer groups consume as their economic situationimproves.So what about my hunch that sugar and sugar-rich foods are driving these better foods out of our diets?We have been able to show that,in theUSA,the gradual improvement in living standards has been accompanied by an increase in the consumption of fruit by the poorest section of the population,but at the same time by a significant decrease in the wealthiest section.In theUK,what we did was to look at the change in consumption of the nutritionally more desirable foods between1936and1983,for both the poorest tenth of the British population and the wealthiest tenth.The Undoubted improvement in the standard of living during the half century was reflected in a significantly improved diet among the poorest section of the population.In the1980s they were taking more than three times as much milk,twice as many eggs,nearly twice as much fish and50per cent more meat.But for the wealthier tenth of the population,the figures that we were able to collect for1936and1983showed a significant reduction in all of these items.The consumption of milk,meat and eggs had fallen by about30percent,and of fish by more than50percent.As for meat,everyone with any experience of the country before the Second World War knows that the poorer people ate little meat(see,for example,the famous studies of John Boyd Orr).Yetin spite of a sizeable increase among the poorer people,average meat consumption in theUK has hardly changed since before the war.This can only have been due to a decrease in consumption by the wealthierpeople.More recent evidence comes from theUSA,where,as you probably know,there has been a considerable outcry by experts in the last few years about the existence of nutritional deficiencies.How Much of a deficiency exists is uncertain.What is certain is that it is much more than most people hadthought.It is unlikely that the fall in the nutritional quality of the average American diet was due to increased economic hardship.The more likely explanation is again that some of the nutritionally good foods were being crowded out by the nutritionally inferior,sugar-based,foods.This is also the belief of Dr Joan Courtless,a member of the US Department of Agriculture,who says: "The surveys themselves show that it [the worsening of diets]lies in the choice being made-increased consumption of soft drinks and decreased consumption of milk;increased consumption of snacks and decreased consumption of vegetables and fruit.'And "snacks'contain large amounts of sugar.
.Can you prove it?
If reading this book convinces you that sugar is in fact pure,white and deadly,you will certainly get involved in a lot of arguments when you try to convince other people.It will help you and stop your being thrown off balance if you carefully consider not only the facts I shall be giving you,but the wider problem of how to weigh evidence about the causes of disease,and how to form your final judgements about these.Before I begin to talk about diabetes and heart disease and duodenal ulcers and several other conditions,I shall discuss this problem in general terms.As you will see,quite a lot of the conclusions I shall bedrawing in this book will inevitably be based partly on factual evidenceand partly on personal judgement.Those of you who have attemptedto follow reports on the enormous amount of research into theproblem of heart disease that has been done and is continuing will notbe surprised when I say that you have to mix objective facts andsubjective opinion.Absolute proof of the cause or causes of any diseaseis sometimes notpossible.To get absolute proof that cigarette smoking causes lung cancer,you would need to take,say,1,000young people at the age of15;pair them off as carefully as you could into two very similar groups of500each;make one group smoke from that time onward and rigidly prevent the other group smoking.Then,after perhaps30or40years,you could begin to see whether a significantly larger number of people in the smoking group had developed lungcancer.Since this sort of experiment is clearly out of the question on ethical as well as on practical grounds,it is necessary to examine evidence that is largely circumstantial,and to judge this against a background comprising,one hopes,rational and plausible general biological principles.I have tried to do this here.I have tried to recognize the limitations of all the evidence that is available,and in interpreting it I have tried to stand back and assess it chiefly on the basis of whether it makes sense,whether it fits in with what can be discerned about the rules that govern living processes and livingorganisms.It is logical then to spend a few minutes looking at both ofthese aspects:to ascertain the kinds of evidence one can hope to findabout the causes of disease and the limitations of this evidence;andalso to see if general laws can be detected that make sense in relationto the maintenance of health.Since I am talking in this bookmostly about sugar,and since the most important disease I shall betalking about is heart disease,I shall refer briefly to sugar and heartdisease,but the same principles apply to any cause and any disease.I ought also to say just a little about the word "cause',because I Am going to talk quite a lot about sugar being a "cause'of a number of diseases.In the first place,it is quite certain that none ofthe diseases I shall be talking about are caused by sugar in the samesort of way that heat causes ice to melt.People differ in theirsusceptibility to disease,so that even in identical conditions-supposing youcould produce them-one man might have a heart attack andanother might not.This susceptibility seems to a large extent to beinherited,so one may say that your chances of getting a coronary are lessif your parents,grandparents,uncles and aunts have mostly lived toa ripe old age without having the disease;the chances are greaterif many members of your family have hadit.In addition to this genetic factor,environmental factors also playa role in coronary disease.Most people accept the propositionthat several environmental factors are influential and that theseinclude leading a sedentary sort of life and smoking cigarettes.What Iam hoping to show is that eating a lot of sugar is anotherenvironmental factor (or cause)in producing heart disease.I do not propose toshow that sugar is the one and only factor involved in producingthis disease,or indeed,anydisease.One more word about causes.If an event A sets off another eventB,and if without A,B would not occur,then you can call Athe cause of B.But suppose I throw a lighted match into mywastepaper basket,and my study and then my house burn down.Wasthe cause the lighted match?Or the loose paper in my waste-paper basket?Or the fact that my house contained lots of books andan excessive amount of wood?If anyone of these factors hadbeen different,the house might not have burned down at all.Alternatively,there might have been a short circuit in the electricalsupply to my desk lamp,so the house might have burned for a reasonquite unrelated to a lightedmatch.I could say that if I eat sugary foods I get holes in my teeth.Then presumably the sugary foods are the cause of dental decay.But I might not get dental decay,in spite of these foods,if I have a high genetic resistance to the disease;or if I brush my teeth immediately after eating these foods;or If I know how to keep my mouth freeof the bacteria that actually attack the teeth after being stimulatedto multiply and to become active by the sugar in food.Is sugar then the "cause'of tooth decay?Or is it the bacteria?Or the lackof resistance of my teeth?So in what follows,I do not expect to show you that a high intake of sugar IS the one and only cause of the diseases I mention.I do hope to persuade you,however,that,whatever yourheredity,and however much you may persist in habits that are involvedin producing one or other of these conditions,your chancesof developing it would be significantly reduced if you reducedyour sugarconsumption.Now what about the sorts of evidence that a particularcause produces a particular disease?Broadly,there are two chief typesof evidence:epidemiological and experimental.By "epidemiological”,I mean evidence that there is an association between the intensity of the supposed cause and the presence of the disease.Suchevidence deals with these sorts ofquestions:Is heart disease more common in populations that eat more sugar?If there.has been an increase in the number of peoplesuffering from the disease,has there also been an increase in theconsumption ofsugar?In any population,has more sugar been eaten by the people that actually have the disease than by those who do not have it? "Experimental'evidence is produced when you attempt to answer these sorts ofquestions:Does the feeding of sugar to animals in a laboratory lead to heartdisease?Does removal of sugar from the diet reduce the chances ofanimals or people getting heartdisease?You may also ask rather less direct questions,such as:shortof producing the disease itself,does the feeding of sugar producethe sorts of changes you normally find associated with thedisease?As to general laws,it seems to me that one or two biological principles ought especially to be remembered in these days of very rapid changes In our environment.First,living organisms can often adapt to change if it is not too rapid,nor too profound.If,however,the change is very rapid and very profound the organisms may succumb.It may be that in a population some individuals will bemore resistant and may survive even though the majority has died.Ifthe change persists,a new population may ultimately arise fromthe survivors,in which all the individuals will be equipped withthis higher resistance.It is likely that,for a fairly considerable alterationto occur in a population,something between1,000and10,000generations are needed.In human terms this would rangeanywhere from30,000to300,000years.The second principle is less obvious,but I believe it is a logical corollary of the first.It is that,if there have been great changes in man's environment that have occurred in a much shorter time than30,000years,there are likely to be signs that man has not fully adapted,and this will probably show itself in the presence of disease of one sort oranother.I know people tend to resent this thought,but I am convinced that you will not find an exception to this rule.Think againof cigarette smoking,which in theUK has increased from anaverage of1,100cigarettes a year per adult in1920to more than2,500cigarettes a year in1980.Think of the rapid decrease ofphysical activity:the use of labour-saving devices,the widespread use ofthe car,the television and radio;all of these have made affluentman into an extraordinarily sedentary animal during the past30or40years.And few today would deny that cigarette smoking is a potent cause of lung cancer and that both cigarette smoking and sedentariness are important causes of heartdisease.I could go on and point to the indisputable fact that every single new drug that has been introduced has sooner or later been shown to produce unintended bad effects as well as the intended good effects-though let me hasten to add that this is of little consequence if the good effects are important and the bad effectsunimportant.If then there is reason to be concerned about a dietary cause of widespread disease,one should look for some constituent of man's diet that has been introduced recently,or has increased considerably recently.And by "recently'I mean over a short period in evolutionary terms,say,10,000years.Conversely,a dietary constituent is unlikely to be the cause of a common disease if it has been a significant part of man's diet for a long time-say one million years or more.If there is a constituent that is new or that now forms a muchlarger part of our diet than previously,one should also ask whathas brought this about.It is these considerations that should be borne in mind when one considers the total evidence that involves sugar consumption in the production of diseases in man.These considerations are so important that it is necessary to look at each of them rather more closely In order to understand their uses and limitations.This is what I propose now to do-not in very great detail,but sufficiently for you to understand why much of what I write in this book hasbeen the.subject of argument and disagreement,and why Inevertheless believe that the total picture is fairly convincing.First,then,epidemiology.The questions seemed reasonably straightforward.How much disease exists in different populations?How does It relate to sugar consumption?And so on.But in fact thereare no easy answers.Take ·the question of the prevalence of disease.To begin with,there is no record anywhere of how many people suffer from a particular disease at any giventime.For example,no one knows how many people inAmerica orBritain have a duodenal ulcer,or even what exactly the prevalence is of dental canes In these countries.The diagnosis of duodenal ulcer,or the measurement of the precise amount of dental decay,is not easy and not sufficiently precise for all physicians to agreein every instance.And even if you were to hazard a guess as tothe prevalence of duodenal ulcer or dental caries by counting,.for example the number of cases treated in hospitals,you couldnot possibly find out the statistics for a country that lacks well-organized medical and dental services-and this applies to more thantwo thirds of the countries in theworld.You might imagine the situation to be easier with those diseases that are often fatal,because you could then look at the recordfor mortality.But once more doctors do not always agree about a diagnosis of coronary thrombosis or particular sorts of cancer.The causes of death that different doctors report in similar casesmay therefore differ.Doctors in different countries tend to havedifferent standards,and statistics from the less well-developed countriesare again often quite unreliable.Epidemiological studies also requireknowledge of food consumption-in this particular instance,knowledge of sugarconsumption.Now it so happens that it is easier to find out how much sugar is currently being eaten in a country than how much is being eaten of any other food.In almost every country in the world all Sugar is produced in factories.Consequently production,export and import are well recorded.But even so,this information may not be sufficient for present purposes.It does not tell you how sugar is distributed through the population,and this it is most important toknow.Let me explain.Imagine two countries with exactly thesame average consumption of sugar-suppose an average of60gramsa day (about two ounces).Suppose that in one country mostpeople eat about40grams,and relatively few eat over100grams a day.In the second country,quite a number of people eat very littlesugar indeed,but a large proportion eat over100grams a day.If itneeds at least100grams of sugar a day to produce coronarythrombosis,then more people would clearly be affected in the secondcountry,even though the average for both countries is the same.I shallhave more to say on this pointlater.There is also the question of how long the disease takes to develop.It seems that coronary thrombosis and also diabetes showthemselves only many years after their onset.Ideally,then,one wants to know people's sugar consumption over perhaps20,30or40years.Itis clearly impossible to get this information.One can only hope thata careful measure of consumption today will in many instancesgive at least some idea of whether people take a lot of sugar,or amoderate amount,or little,and also whether they have maintained thishabit for much of theirlives.These then are some of the limitations ofepidemiological evidence.One cannot of course ignore such evidence;thequestions to be answered here are too important to discard any possibleclues as to the cause of diseases such as coronary thrombosis.Butyou should constantly bear in mind the limitations of this type of evidence.Especially you should not be surprised if it seems lessthan conclusive;you may have to be content if it simply gives an i4eaabout a possible cause that can then be followed up by researchin otherdirections.Under the heading of epidemiology,I also include evolutionary findings.Here the chief limitations are the uncertainty of some of the records.While most anthropological authorities take the view that man has been a meat-eater for several millions of years,they do not have an exact picture of what he ate and especially how much he ate of each food.The presence of large numbers of animal bones near human remains make it certain that he ate some meat,but it can be argued that meat was only a small part of his diet,that he ate mostly vegetable foods,and that these were bound to leave far less in the way of evidence compared with animal bones.This is not the place to argue the matter in detail,but I am in agreement withthe majority who hold that primitive man was largely carnivorous.All in all,epidemiological evidence rarely providesconclusive proof of the relationship between diet and disease.It will,however,add important information to my case,and the total evidencewill,I hope,be sufficient to convince you "beyond reasonable doubt'.So far,I have been talking about the epidemiologicalevidence that you get from a study of populations.But you can alsoget epidemiological evidence to do with the relation between a diseaseand its possible cause in individuals that make up a population.Youcan do this either after or before they develop the disease.Forinstance,you can find out whether people who have developed lungcancer were or were not cigarette-smokers:this is called aretrospective study.Or you can keep in touch with people of whom someare cigarette smokers and some not,and then see how many ofeach group later develop lung cancer:this is a prospective study.Whichever form your study takes,you will try and ensure that thepeople in the two groups differ,as far as you can discover,only intheir smoking habits and are similar in every other way.You can seethat it is easier to do this with individuals than with populations.If,for example,it is true that a population of rural Africans is muchless likely to have cases of appendicitis than is apopulation ofBritish town-dwellers,you could say it is because the Africans eatmore fibre,or less fat,or less sugar-or indeed less food;or you couldsay that it is not because of their diet but because they do not ridein motor cars or watch television,but are physically more active.If,on the other hand,you find in the same town that men who have just had a heart attack have been eating more sugar than have men of the same age and social class who have not had a heart attack,you have a piece of evidence that sugar may be a possible cause of heartattack.I now turn to experimental evidence of,what causes disease,the sorts of ways in which this evidence is gathered and the ways in which it can be legitimatelyinterpreted.One of the best ways to understand human disease is to reproduce the condition in rats or guinea pigs or other laboratory animals.By This means medicine has gained a good understanding,though by no means yet complete,of such hormone diseases'as excess or deficiency of the thyroid hormone or the hormones of the pituitary gland or of the parathyroid glands.Again,most modern knowledge73about nutrition-about calories and protein and vitamins andmineral elements-comes from work with laboratory animals.On the other hand,when we can't produce a disease inanimals,we are tremendously handicapped.There was a long delaybefore medicine found out how to treat pernicious anaemia.Thiswas because every suggested treatment had to be tried on patientswith the disease.After very many years of hard research work,itwas discovered that the eating of raw or lightly cooked liver was effective.Then,whenever a new extract from liver was made,it had tobe tested in a patient with untreated pernicious anaemia.It was only after an interval of23years that this workultimately resulted in the discovery that the active therapeutic agent inliver was vitamin Bu.There is no doubt that this long intervalwould have been very much reduced if the researchers could havebeen conducting the same tests on rats or rabbits or some other animalin thelaboratory.Coronary disease as it occurs in man has not been producedin any of the ordinary laboratory animals.There have beensuggestions that it has been produced in some primates,but no one yetknows whether this can be done regularly and at will.In any event,itis going to be extremely difficult and costly to set up a laboratorywith the hundreds of monkeys that would be necessary in order to carryout all the experiments needed to get somewhere near solvingthe problem of coronarydisease.What can be done more easily is to try and reproduce inlaboratory animals as many as possible of the characteristics that are found tobe commonly associated with the disease in man.The onecharacteristic that everyone has talked about for years is a raised level ofblood cholesterol.It is widely accepted that the chances of someonedeveloping a heart attack are higher when blood cholesterol is higher.Itis reasonable,then,to suppose that the experimentalmanipulation of the diet or of other conditions that raise the level ofblood cholesterol in animals may be concerned with producingcoronary disease in man.As everybody knows,there have been thousands ofthese sorts of experiments.But people with coronary disease often have other abnormalities as well as an increase in bloodcholesterol,and producing these experimentally can also help in identifying what causes thedisease.One important characteristic of coronary disease is the occurrence of those changes in the arteries known as "atherosclerosis',which are described in a later chapter.Not all animals are equally susceptible to this condition.It is relatively easy to produce changes in the arteries of rabbits,but much more difficult in rats.And when one does produce fatty changes in the arteries,there is always the question as to whether they are the same as those that occur in human atherosclerosis.There was for a long time-and there is still in some minds-a doubt whether what is produced in the rabbit is really similar to the condition in people.Occasionally,enthusiastic research workers are carried away sufficiently to claim that they have produced experimental atherosclerosis when what they have really produced is something demonstrably and grossly different.What one would like to see would be experiments that producemany of the characteristics of coronary thrombosis all togetherin the same animals by the same means.Still better,if it is notpossible to produce coronary thrombosis itself,would be to see thesame experiments carded out in several species of animals,so noone could be misled by some unusual response in the particularspecies that happened to bestudied.One ought also to take into account something of thenormal habits of the animals.If,for example,we are studying the effects of diet,it does notseem to me to be sensible to include foods that are not normally part of the animal's diet or normally part of a human diet.The diets of herbivorous animals like the rabbit ordinarily contain very little fat and virtually no cholesterol.It is not surprising to me that diets high in fat and containing cholesterol produce abnormalities in rabbits.I do not believe that this should be acceptedas proof that similar diets will produce similar effects incarnivorous or omnivorous species of animals,including human beings,whohave consumed such diets for hundreds of thousands ofyears.As well as experimenting with animals,one could also do experiments with human beings provided one could be sure that no harmful effects would be produced.The intention would clearly be not to produce coronary thrombosis but to produce temporarily the sorts of changes that are known to accompany the disease.Once again,the commonest change that has been looked for is an increase in the level of cholesterol in theblood.Let me break off for a moment to make a point about what sorts of measurements research workers carry out when they perform experiments such as those I have been talking about.Of course,a most important guiding principle is to measure the substances that,like cholesterol,are known to be considerably changed in concentration in the condition that is being examined.But research is often limited by the methods available for carrying out the measurements.It may be that for a particular substance either no method exists or none that is suitable for routine use,since it may require very special apparatus or may involve very laborious techniques.Conversely,it may be that quite simple methods exist for measuring thesubstance,even though it may not be-or may turn out not to be-very relevant to the disease beingstudied.This,I believe,is the position with studies on coronary disease.If it is true-and I am still far from convinced-that the most important change in this condition is the increased level of someof the fatty materials in the blood,then there is a lot to be said for the view of many workers that levels of other fatty substances are more informative than levels of cholesterol.One such substance is triglyceride'another is one of the particular compounds that holds the cholesterol in the blood.This is the cholesterol bound to high density lipoprotein ("HDL cholesterol')which is now accepted as a better indicator of coronary risk than the total amount of cholesterol.Indeed,not everyone is convinced that,in most people,muchinformation is gained from measuring only total cholesterol.Onedistinguished American research physician.has written thatblood cholesterol is a biochemical measurement still in search of clinical Significance!One final sort of experimental evidence is to see what will cureor prevent the disease;from this,within reason,one can draw.conclusions about the cause.An obvious example IS scurvy,whichis cured by giving oranges or lemons;it was this discovery that.ultimately led to the identification of the cause of scurvy:adeficiency of vitamin C,which is contained in fruits and vegetables..But there are two possible ways in which one can be misled,one obvious and one less obvious.The obvious one,thoughoften overlooked,is that there are some conditions,like therheumatic diseases,in which the symptoms fluctuate.A period of pain isfrequently followed by a period of remission,so that anytreatment given while the disease is worrying the patient is likely to bethought to have produced the subsequent improvement..One can also fall into a rather more subtle trap.I can best explainthis by an example.Many older people who suffer from a varietyof diseases gradually develop a degree of heart failure,and one ofthe effects is swollen legs due to dropsy (oedema).This can berelieved if large amounts of vitamin C are taken,for the vitamin acts asa diuretic and increases the loss of fluid through the kidneys.Yet although this treatment is curing a symptom of heart failure,the condition is clearly not due to a deficiency of vitamin C.A more obvious example,if perhaps a rather ridiculous one,is that curing a headache with aspirin does not imply that theheadache was caused by aspirindeficiency.Let me here refer to the results of experiments on the effectof changing the diet in attempts to prevent coronary disease.Since these experiments have all been designed to test the effect ofaltering the fat content of the diet,and not the effect of altering thesugar content,it will be best to discuss these experiments at thispoint rather than later,when I shall be concentrating on the caseagainst sugar.It is also useful to do this here because I shall be ableto demonstrate another of the difficulties of research into thesubject of diet and heartdisease.There have been several experiments,or trials,in which fatintake was changed by reducing the amount of saturated fats like butterfat and meat fat,sometimes also adding vegetable oil like corn oil.In some trials,the doctors studied people who had already had oneor more attacks of coronary disease.The research workers tried to see whether the change of diet reduced the patients'chances of getting another attack compared with a similar group whose diet had not beenchanged.This sort of study is called a "secondary prevention trial'.The Other sort of study is the "primary prevention trial',in which the investigators change the diet of apparently healthy men and see how any develop coronary disease,again compared with a matched group whose diet has not beenchanged.Several trials of each sort have now taken place,the most important being those attempting primaryprevention.One was in a veterans(ex-service)centre inLos Angeles,in which424men wereput on an experimental diet with reduced saturated fat andcholesterol,and increased polyunsaturated fat.During the next five yearsthe researchers compared these men with422men whose diet wasnot changed.It turned out that there were63deaths fromcoronary disease in the experimental group and82in the control group;however,the number of deaths from all causes was the same inboth groups.One unwelcome result was that more of the men inthe experimental group developedgallstones.A trial inHelsinki lasted15years.This involved patients in two different mental hospitals.In one,the patients received the standard Finnish diet,and in the other a diet with a high proportion of polyunsaturated fats.After five years the diets were switched.Atthe end of the15-year experiment there were somewhat fewercoronary deaths in the two hospitals during the time patients were takingthe experimental diet.However,in this trial,too,there was nodifference in the total number of deaths from all causes.The waythe experiment was conducted has been strongly criticized:forexample,as patients left either of the hospitals,other patients were taken into replenish the trial numbers,so that the study was conductednot with a constant population,but with.patients who had been inthe experiment for widely varyingtimes.Later trials have examined the effect of changing other itemsas well as the amount of dietary fat,although they have notchanged the proportion of polyunsaturated fat.One such study was inthe United States MR FIT (Multiple Risk Factor Intervention Trial),reported in1982.More than12,000middle-aged men withhigh coronary risk factors took part,and half of them were giveninstructions aimed at reducing their cholesterol level,blood pressure,and smoking habits.They were frequently interviewed andencouraged to persist in these measures.After seven years their blood cholesterol concentration had fallen by only2per cent,their mortality from coronary disease was not significantly different from that of the control group,and their total mortality was somewhat higher.The Cost of this study was over100million dollars.In1984there were reports of the Lipid Research Clinics Primary Prevention Trial.The purpose of this trial,however,was to study not the effect of diet,but the effects of the administration of a cholesterol-reducing drug,cholestyramine.Like the MR FIT experiment,the subjects were men-about2,000of them-selected because of their high coronary risk,in that they had blood cholesterol values in the highest5per cent of the values in the population.All were instructed to take a low-fat diet and half of them were given the cholestyramine.At the end of seven years,both groups showed a decrease in their blood cholesterol,and the reduction was significantly more in the drug group.These also had nearly a quarter fewer deaths from coronary disease and a significantly smaller number of non-fatal heart attacks.Unfortunately,this desirable effect of the drug was accompanied by quite unpleasant gastric symptoms,so that many of the men in the drug group gave up taking it.Clearly,the mass treatment of thepopulation with this drug is not really practicable.Moreover,it would be enormously expensive;it has been calculated that it would cost about a quarter of a million dollars to prevent a single heart attack.A trial that is still proceeding is the Stanford Heart Disease Prevention Program.This began with a massive publicity campaign in two Californian towns,involving television and radioprogrammes,regular newspaper articles,advertisements,and propaganda material through the post.The effect was a3-per-cent reduction in the concentration of blood cholesterol,which after the end of the campaign reverted to only a I-per-cent reduction.In spite ofthis,the next phase planned is a repetition of the trial on a bigger scale,.involving five Californiantowns.We must conclude that all this effort since the1960s hasnot succeeded in demonstrating the efficacy of a change in dietary fatin reducing the prevalence of coronary disease.And yet thefact remains that,since about1960in theUSA,and somewhat laterin other countries,there has been a decline in the number ofpeople recorded as dying of coronary disease.In theUSA,there hasalso been a small decrease in total fat consumption,but thisdietary change began some years after the fall in coronary deaths began.There have also been other changes in life style,both inAmerica and in theUK,as well as in some other countries,although not allof them are quantifiable.These changes include a decrease in cigarette smoking,an increase in physical programmes such as jogging and"aerobics”,a more widespread attempt to control high bloodpressure,and a vast number of coronary bypass operations on people with heart disease.In most of these countries there has also been asmall but continuing decrease in sugar consumption.The factremains though that we do not know why there has been this declinein coronary deaths,but it is of course verywelcome.It may turn out in the end that people would reduce their chances of getting heart attacks if they took large quantities of polyunsaturated fats such as those found in maize (corn)oil or in sunflower-seed oil,or in the special sorts of margarines made with these oils.I have to say however that I think it very unlikely that this will happen.I believe that the best diet for the human species is one made up as far as possible of the foods that were available in our hunting and food-gathering days.The oils rich in polyunsaturates have been available only because of recent advances in agriculture and in the even more recent elaborate industrial techniques of extracting and refining oils;the complex chemical processing of these and other oils to produce margarine removes this product even further from the sorts of foods available to humanity duringmillions of years of evolution.
13.Coronary thrombosis,the modern epidemic
No one today can be unaware of thetremendous concern about the large number of people dying from coronaryheart disease.InAmerica andBritain,they account for more thanone fifth of all deaths.In these and other affluent countries,at leastone out of three men over the age of45will die of heart disease.It isnot surprising that in books,magazines,radio and televisionprogrammes much has been made of this problem over the past25years.But I find that there is still such a lot ofmisunderstanding about the nature of heart disease that I had better clear the airwith definitions and descriptions before going on to consider the causes.It may well be that you already have what you believe is anice,simple picture of heart disease and how it comes about.If so,it probably goes like this:There is a fatty material io.â€'1bloodcalled cholesterol.As you grow older,the amount of cholesterol inthe blood increases,especially if you have food that contains toomuch meat fat or butter fat.Because of the high level of cholesterol inthe blood,some of it tends to become deposited on the inside ofthe walls of the arteries,including the coronary arteries.Thesesupply blood to the thick muscle that makes up the wall of the heart,which pumps the blood round the body.The gradual narrowing ofthe coronary arteries by the deposited cholesterol reduces theblood supply to the heart,and you then get pain in the chest whenyou exercise-angina,or,more correctly,angina pectoris.The cholesterol deposits also encourage blood clots to form,so that sooner or later one or other coronary artery,or one oftheir branches,becomes completely blocked.As a result,the bloodsupply to a larger or smaller part of the heart is cut off,and then you81have your heart attack-pain,unconsciousness if the heartstops,death if it does not soon start beatingagain.This view of a coronary attack is oversimplified;it issufficiently misleading for me to ask you to bear with me while I go throughthe story again in more detail,and more in keeping with the real events.Especially,I want to differentiate between what medicine knowsis happening,and what research is still uncertain about.Like any other organ of the body,the heart can be affectedby many different sorts of disease,so that strictly speaking it is assilly to speak of heart disease as it would be to speak of arm or leg disease.What people usually mean by heart disease is what is variouslycalled coronary heart disease,or coronary thrombosis,ormyocardial infarction,or ischaemic heart disease.Even this statement,however,is rather misleading because these conditions are not quitethe same.You will understand the situation better if you try tofollow the disease process as it affects the heart-in so far,that is,asscience understands it.I say this because in many ways no one is as yetclear about the development of the condition,or conditions.In human terms,almost everybody knows what I am discussing.One common picture is that of an individual,more usually aman than a woman,and most commonly over the age of60,who isoften apparently quite healthy until he is stricken with a severe painin the chest.He may fall unconscious and may not recover;or thepain may gradually diminish and he is put to bed.If he does recoverfrom his first attack,he may have subsequent attacks after a shorter ora longer time,with again the chance that one of these will prove fatal.Sometimes the events are different.The picture then is of aperson,again often apparently well,who dies so suddenly that he hasvirtually no time to complain of pain or of any other symptom.The course of events leading to the established disease ordiseases is unfortunately not at all clear.Indeed,whatever I now write,however carefully,will represent the views of many of the experts in this field,or even most of them,but there will always remain some who will disagree with some or all of the events as I outlinethem.Let me begin by talking about the so-called "deposit'on the inside walls of the arteries.The deposit is called "atheroma',the condition is called "atheromatosis'.The word "atheroma'is Greek for "porridge',and refers to the irregular patches of yellowish material found on the insides of the walls of the arteries;these patches are sometimes called "plaques'.No one is quite sure what starts the process.Many believe that it starts with an aggregation of blood platelets on or in the wall of an artery.The platelets are tiny discrete bodies in very large numbers,floating in the blood together with the red and white blood corpuscles.When they stick together in this waythey encourage the formation of tiny blood clots.Around these dotsthere is gradually built up a mass of fatty material that includes afairly high proportion of cholesterol.In due course,these patchesbecome fibrous,much as scars form on a cut on the skin.It is thecombination of atheroma and fibrous scars that leads to this stagebeing known as atherosclerosis.Later still the plaques may degenerateand become chalky andhard.Atherosclerosis can occur in arteries all over the body,although It IS more likely to occur in some sites than in others.It probably starts at quite an early age,perhaps in the teens;according to some authorities:It starts even earlier.As it develops it may begin to interfere with the flow of blood so that exercise may give you a pain in the chest because of narrowing of the coronary vessels (angina),or Pain in the legs because of narrowing of the arteries to the legs (peripheral vascular disease,also known as thromboangiitis obliterans,or Buerger's disease).In peripheral vascular disease,an increase in the extent of atherosclerosis leads to pain in the legs after you have walked for a shorter or longer distance.If the condition is not treated,there comes atime when the blood supply to the extremities is so diminished that atoe may begin to die of gangrene,or the whole foot,or even part ofthe lower leg.Treatment may consist of drugs that widen thearteries,or of operative procedures to improve the circulation bystripping the arteries of their atheromatousmaterial.In the heart.,the coronary arteries may become increasingly blocked,resulting in more and more severe angina brought on by less and less effort.A more complete blocking may also occur,with or without previous angina.It could be that the blockage is due to a blood dot;this occurs more readily in an artery with atheromatous patches,partly because of the slow rate of flow of the blood and partly because the normally smooth interior of the artery now contains rough atheromatous material.But a block may alsooccur because the narrow coronary artery just goes into a spasm orcontraction long enough to cut off the blood supply and cause a heartattack.The outcome depends on several things.One is the size of the portion of the heart that was supplied by the artery before it becomes blocked.A second factor is the particular portion that loses its blood supply,because some portions are very much more important in keeping the heart beating than others.Thirdly,theoutcome depends on whether the relevant section of the heart has bloodvessels coming to it from a different direction,which can rapidlyexpand and bring enough blood to it by this alternative route.If the affected section of the heart is small or relativelyunimportant,the heart will stop for only a short time or not at all.If aportion of the heart has permanently lost its blood supply,that portionmay die.This is called myocardial infarction and can be seen yearslater in the heart where the dead tissue has become replaced withscar tissue.It seems that something quite different occurs in sudden death.It is probably also associated with severe atherosclerosis of the coronary arteries,but what appears to happen in this instance is that the heart stops beating normally and goes into a sort of very rapid shivering,known as "ventricular fibrillation'.This rendersineffective the heart's job of forcibly and regularly pumping bloodround the body,and death ensues very rapidlyindeed.It is important to remember that it is possible to have quite extensive atherosclerosis without any symptoms at all.If so,it willbe impossible to diagnose the condition unless some of the atheroma has proceeded to the extent of becoming chalky so that it shows in an X-ray film.Most if not all adults in the well-off countries live with at least a fair degree of atheroma but if they have no symptoms it is usually impossible to tell whether they do have atherosclerosis,and if so how much orwhere.I hope you do not think that this has nothing to do with thesubject of this book.One of my main reasons for taking up research inthis field was that I became more and more uneasy about theprevalent simplistic view of how people get coronary disease-the idea thatit is just a matter of cholesterol levels in the blood.This idea isnow so firmly held by so very many people that they end upbelieving that anything that increases cholesterol in the blood is likely tocause coronary disease,that anything that reduces cholesterol helpsto prevent the disease or even cure it,and that anything that doesnot invariably increase the cholesterol in the blood must havenothing whatever to do with the cause of heart disease.I know I am biased,but this picture-in my view arather naive one-has hindered a proper understanding of the diseaseand its causes and so a proper understanding of itsprevention.In fact,people with coronary disease are afflicted with very much more extensive disturbances than just a rise in the level of cholesterol In the blood.For One thing,there is a rise in other fatty components in the blood,especially the triglycerides,sometimes calledneutral fats;many people believe this rise occurs more frequently than does the rise in cholesterol.There is also a fall in the H D L cholesterol.Secondly,other biochemical changes take place includingdisturbance of the metabolism of glucose or blood sugar in the samedirection as that found in diabetes.There is often a rise in the levelof insulin and other hormones in the blood,and sometimes a risein uric acid.There are alterations in the activity of several enzymes.The behaviour of the blood platelets is changed.One could produce a list of at least twenty indicators thatoften register abnormally high,or abnormally low,in people thathave severe atherosclerosis,and only one of these is the frequentthough not at all universal rise in the level ofcholesterol.If you seek further evidence about the possible role of sugar or any other factor in producing heart disease in man,you should bear in mind the complexity of manifestations of the disease.This is particularly important in the sort of experiments mycolleagues’ and I have conducted with laboratory animals.I shall talk aboutthese in more detail in the next chapter.The first proponent of the idea that fat could be a cause of coronary thrombosis,and since then its most vigorous defender,was DrAncel Keys of Minneapolis.In1953he drew attention to the fact that there was a highly suggestive relationship between the intakeof fat in six different countries and their death rate fromcoronary disease.This was certainly one of the most importantcontributions made to the study of heart disease.It has been responsible foran avalanche of reports by other research workers throughoutthe world;it has changed the diets of hundreds of thousands ofpeople ‘and it has made huge sums of money for producers of foods thatare incorporated into these specialdiets.As a result,too,a very great deal is now known about theeffect of different diets upon the processes of metabolism in the body,and especially upon the processes of fat metabolism.And yet there isa sizeable minority of research workers,of whom I am one,who believe that coronary disease is not largely due to fat in thediet.Let me start to argue the case by looking more closely at the epidemiological evidence of the relationship between diet and coronary disease.From the beginning,a few people were a little uneasy about Dr Key's evidence.Figures for coronary mortality and fat consumption existed for many more countries than the six referred to by Keys,and these other figures did not seem to fit into the beautiful straight“line relationship-the more fat,the morecoronary disease-that was evident when only the six selected countries wereconsidered.Also evidence began to accumulate that not all fats were thesame;some seemed to be good,some bad,some neutral.At first,thiswas strenuously denied by Dr Keys,but by1956or so thesedifferences were accepted by him as they were by all other workers.The "bad fats were mostly animal fats such as those in meat and dairy products(saturated fats).The "good'fats were mostly vegetable oils (polyunsaturated fats).The "neutral'fats were neither good nor bad;an example is olive oil (mostly a monounsaturated fat).It seemed appropriate to look much more closely at the figures of mortality and fat consumption than had been done hitherto,and this I did in1957.By putting down all the information available from international statistics,I found that there was a moderate but by no means excellent relationship between fat consumption and coronary mortality,which did not become closer even when one separated the fats into animal and vegetable.A better relationship turned out to exist between sugar consumption and coronary mortality in a variety of countries.The best relationship of all existed between the rise in the number of reported coronary deaths in theUK and the rise in the number of radio and televisionsets.Making this last point serves two purposes,I think.