Food and Health: The Experts Agree

An analysis of one hundred authoritative
scientific reports on food, nutrition and
public health published throughout the world
in thirty years, between 1961 and 1991

by Geoffrey Cannon

Where a consensus exists about the dangers arising from the consumption of certain foods the Government shall have a duty to bring this to the attention of the public.
    Recommendation 45 of the Expenditure Committee of the House of Commons (Social Services and Employment Sub-Committee) report on Preventive Medicine, 1977. Accepted by the UK Government in its White Paper on Prevention and Health, 1977.
Whether the object is to avoid cancer, coronary heart disease, hypertension, diabetes, diverticular disease, duodenal ulcer, or constipation, there is broad agreement among research workers that the type of diet that is least likely to cause disease is one that provides a high proportion of calories in wholegrain cereals, vegetables and fruit; provides most of its animal protein in fish and poultry; limits the intake of fats and, if oils are to be used, gives preference to liquid vegetable oils; includes very few dairy products, eggs, and little refined sugar.
    Sir Richard Doll: 'Prospects for Prevention'. The Harveian Oration, 1982.
Medical and scientific research has established clear links between dietary factors and the risk of developing coronary heart disease, hypertension, stroke, several cancers, osteoporosis, diabetes, and other chronic diseases. This knowledge is now sufficiently strong to enable governments to assess national eating patterns, identify risks, and then protect their populations through policies that make healthy food choices the easy choices.
    Executive Summary, 'Diet, Nutrition and the Prevention of Chronic Diseases'. World Health Organisation, 1990.



Nutrition is a science which has immediate appeal for the public, and also enormous economic and social significance for agriculture, the food industry and the consumer. Its effect on disease patterns is profound: nutritional issues underlie the provision of health care in countries throughout the world. Nutritional scientists have therefore always been concerned with public health.

Early this century, as each vitamin was discovered, a new dimension to public health was revealed. By the beginning of the Second World War it was obvious that nutrition was crucial to national survival. British and other governments therefore took on new responsibilities for the provision of a food supply adequate for health, and a wave of measures to improve nutrition and health education were introduced. The collaboration between scientists, doctors and government proved to be so successful that it seemed obvious that the principal nutritional issues relating to public health had been resolved. The focus therefore shifted to a demand for more food production to ensure that everybody, the poor as well as the better-off, had plenty to eat.

After the war almost all British research into the nutritional needs of children and adults was abandoned. There was a huge national drive to increase milk and meat output, and to intensify agricultural production. Massive government subsidies to farmers and controls on marketing were backed by the development of one of the most effective agricultural research and advisory systems in the world. The collaboration between scientists and the fertiliser, agrochemical, farm machinery, seed plant breeding and animal husbandry industries was unprecedented. Food production increased hugely, and the food industry developed to produce ever cheaper food: the real cost of the weekly household food bills plummeted. The Department of Health was little concerned with nutritional issues other than the composition of baby milk for the majority of mothers who no longer breast fed their babies. The Ministry of Agriculture continued to maintain its declared priority of supporting the farming and food industries. The need for cheap foods adequate in protein, energy, vitamins and minerals was agreed by all.

These developments were not confined to the UK, but British scientists had made a major contribution to discovering the vitamins and the use of nutritional supplements to promote the growth of small children from poor families. The public health and agricultural policies developed in Britain influenced other European governments. The policies on agricultural production were transferred to the Commonwealth and colonies and soon pervaded the world. A whole generation of British economists and industrialists, of government officials and their advisors, of farmers and food technologists, have been brought up sure that their first priority is to provide enough food, based on the nutritional principles identified in the 1930s. But those nutritional principles are now out of date.

And this is why Geoffrey Cannon's review of modern scientific thinking on food, nutrition and public health is so important. It is essential to show a wide range of opinion leaders, often unaware of nutritional advances in the last twenty-five years, that the perceptions of healthy eating used in the 1930s and 1940s are now obsolete. They were limited to the prevention of the classic deficiency diseases and could take no account of the long term effects of eating so much milk and meats with their high levels of fat.

After the Second World War there was a progressive increase in heart disease in many northern European countries. By the 1970s, it had reached epidemic proportions with 200,000 deaths per year in the UK. The medical profession responded with special clinics, coronary care units, flying ambulances and new techniques for major heart surgery. New drugs for controlling abnormal heart rhythms, blood pressure and clotting were also a help, but the epidemic continued. I remember coping, as a young doctor, with an endless line of beds occupied by middle-aged and elderly men undergoing their six week bed rest after their heart attack. Shortly thereafter this bed rest was shown to be of more harm than help.

In 1976 the Royal College of Physicians published a report stating that diet played a major role in coronary heart disease and that the whole British population should change their diet to reduce their saturated fat intake. This recommendation was stimulated by a report produced two years previously by a sceptical group of doctors and scientists working to the Department of Health They had suggested that a reduction in total fat might be beneficial, particularly in those patients who were obese. As a senior lecturer in nutrition with a developing interest in public health, I was aware of these developments but confused by the limited medical responses. Perhaps a personal view of subsequent events will show just how slow the UK has proved to be in recognising the great revolution of diet in relation not only to heart disease but also to a great range of chronic diseases of public health significance.

In 1979 I was invited by the BBC to launch a weekly series on nutrition education. The public response was so intense and supportive that it was obvious that we had stumbled on an area of preventive medicine and individual behaviour which had been neglected for decades. I was then invited to join the National Advisory Committee for Nutrition Education (NACNE) and discovered that nutrition education was still based on ideas more appropriate to 1939 than to 1979. Small vulnerable groups were being targeted for advice on avoidance of vitamin deficiencies. The issues of dental caries, heart disease, strokes, obesity and a host of other diet- related issues were not even considered. On NACNE we developed a new set of priorities; but our proposed change in the strategy of national nutrition education was soon seen as revolutionary and premature. Officials from the Department of Health considered that it trespassed on their own province of policy-making; and the British Nutrition Foundation reflected the alarm of food manufacturing industries concerned at the threat to their profitable business. Despite, however, efforts by government and industry to stall the process, it became clear that opposition could not be supported by scientific or public health arguments; and understandable self-interest was overcome when the delay and obfuscation was exposed by The Sunday Times and The Lancet in the summer of 1983. The expose and subsequent publicity for the NACNE report led to remarkable changes in the approach of the voluntary sector. Government departments then had to struggle to shift from opposing the NACNE report to cope with public demand for free access to clear advice on diet and its relationship to health.

I was then approached by the European Office of WHO to develop a European policy document, covering not only western and Mediterranean Europe, but also central and eastern Europe. This presented the opportunity to learn from Swedish, Polish and Italian colleagues of the efforts being made elsewhere to change national thinking on diet and health. The WHO report 'Healthy Nutrition was published in 1988 and soon became WHO's best seller. It also formed the background to the first WHO/FAO Conference in Budapest in October 1990 for European Ministers of Health and Agriculture to consider national nutrition and health policies throughout the European region.

In 1990 WHO published the first scientific analysis of diet in relation to both deficiency diseases and the adult chronic diseases, encompassing the Third World as well as affluent societies. The message is now clear. Wherever we look in the world, expert groups of scientists and doctors are coming to similar conclusions about the importance of diet and its major role in promoting health and limiting the development of a great many chronic diseases. Opinion is converging, because the evidence shows that we have, for decades, taken too limited a view of the public health aspects of nutrition. Although many further developments can be expected as research continues, the simplicity of the conclusions drawn so far is impressive. We now know that disease-specific diets are not necessary. A diet rich in whole grain cereals, vegetables and fruits, and low in fats, sugar and salt helps to prevent a whole spectrum of diseases. The problem is that the UK and many other northern and eastern European countries have unhealthy diets. A wonderful variety of culinary traditions from throughout Europe, and indeed from the rest of the world, can contribute to a healthy diet; but we have almost forgotten our heritage of appropriate cooking skills.

Now, at last, we in the UK are moving to repair the damage from years of neglect. Voluntary organisations such as the Coronary Prevention Group and the National Food Alliance are promoting a new approach to food policy. In April 1991 Consumers' Association organised, in the Houses of Parliament, the British launch of the 1990 WHO report. The Guild of Food Writers and the Coronary Prevention Group produced a special booklet on a healthy diet for the UK6. With the National Federation of Women's Institutes and the National Consumer Council supporting this initiative, there is a great opportunity to enhance our approach as a nation to maintaining good health into old age.

Why is this review of expert reports published between 1961 and 1991 necessary? Simply because we have such a confused array of opinion, leaders, officials and senior businessmen still locked into obsolete concepts about diet and health. They can think of nothing in relation to health or nutrition except deficiency disease and the individual's genetic susceptibility to specific conditions like obesity, high blood pressure or cancer. European public health specialists are astonished to witness the endless disputes between doctors, scientists and business people in the UK on the subject of diet and the continual claim that 'the experts disagree': for the great majority of experts world-wide actually do agree.

We have to persuade the sceptics to stop thinking of the major Western diseases as a result of personal over-indulgence. This is both wrong and highly destructive. We need to change the national priorities for preventive medicine. We need more action from government and non- governmental organisations to promote public health and healthy eating. We need to overcome the extraordinary inertia and even sabotage emanating from a combination of cynicism, interests vested in the old order, and from quirky or irresponsible scientists who try to confuse public discussion about the validity of the current recommendations. We know perhaps half the explanations for heart disease, but the issue is not whether we should wait for ten years or half a century for a supposedly complete picture. The priority is to encourage society as a whole to eat a healthy diet, as is now well understood. Millions of adults and their families in the UK should then benefit. The average UK diet is currently so unhealthy that the whole population is at risk of unnecessary and preventable diseases.

The lead now being given by voluntary organisations may well prove vital in the promotion of a healthy diet, and good individual and public health in the UK. This review by Geoffrey Cannon shows that the experts do agree; and it provides a basis from which we can move forward to limit the unnecessary grief and suffering caused by so many readily preventable diseases. Consumers Association is to be applauded for publishing and promoting this vitally important contribution towards understanding the new public health, in the UK and throughout the world.

Professor Philip James
Director, Rowett Research Institute


After heart disease, cancer is now the biggest killer disease in most developed Western countries. People are more frightened of death from cancer than death from a heart attack. Until AIDS, cancer was the unspeakable, unnameable disease. Now, in Britain, America and other industrialised countries, cancer kills over one in every five people. And the incidence of cancer is on the increase. The Independent, reporting a scientific survey published in The Lancet in August 1990, stated:101

Western food and cancer

During the 1970s the mounting evidence connecting diet with cancer had been obscured, partly because of the emphasis on diet and cardiovascular diseases, partly because of the medical profession's campaign against smoking, the key cause of lung cancer. But in 1982 a massive report, 'Diet, Nutrition and Cancer', published in the USA by the National Research Council of the National Academy of Sciences, identified a new consensus, and a further indictment of the Western diet.

'Diet, Nutrition and Cancer' was commissioned from the National Academy of Sciences, by the National Cancer Institute in the USA. Its brief was to:
In a chapter written for the general reader, 'Diet, Nutrition and Cancer' explains that, lung cancer aside, the most common cause of cancers is almost certainly not carcinogens like cigarette smoke or industrial pollution. Nor, typically are cancers inherited. In fact:
People may be born predisposed to cancer, just as people may be born predisposed to obesity, diabetes or heart disease, but it appears that the key causes of cancer are environmental. What are the most likely causes?
It is much easier to agree that smoking causes cancer, than to agree that diet (or, rather, certain types of foodstuff) causes cancer. We don't have to smoke; we do have to eat. The chemistry of cigarette smoke is complex, but not as complex as that of food. Besides, 'it is much harder to find out what someone is eating than whether or not they smoke. It is important therefore that we prepare ourselves for a period of uncertainty, between our present realisation that diet affects cancer and our eventual ability to offer the public a precise formula for minimising the incidence'. Nevertheless:
In common with previous expert reports on diet and heart disease, 'Diet, Nutrition and Cancer' points out that the circumstantial case against the industrialised diet, and against fats in particular, is strong. In the half-century between the 1920s and the 1970s the percentage of calories from grains in the American food supply halved, while the percentage from fats increased by over one-third. ~e figures for other Western countries are much the same.) The types of fat that have most increased are not only animal fats, but also vegetable fats and oils that are blended and made into saturated fats by the hydrogenation process, in manufactured foods.

Is fat, eaten in excess, an important cause of cancers? In itself the rise of the consumption of fats is not significant - this century has also seen an increase in air travel and television sets. But the evidence against fats is plausible: as with heart disease, epidemiological evidence of which population studies are one example, is backed by laboratory work:
With colon cancer, the case for dietary fibre is consistent with the case against dietary fat: a diet containing a lot of dietary fibre from cereals, vegetables and fruit is very likely to be a low-fat diet. And 'Diet, Nutrition and Cancer' identifies a high-fat diet as a probable cause of another major disease: 'Information derived from a number of different types of studies supports the association of diet, especially high fat diets, with breast cancer.' Accordingly, a cut in consumption of fats in the average US diet, from 40 per cent to 30 per cent of total calories, is recommended: the same recommendation as for the prevention of heart attacks. What is so special about the 30 per cent figure?
In other words, the thinking behind setting dietary goals - targets - is public health thinking: based on science, but incorporating practical considerations. Dietary goals are usually compromises between what is ideal, and what the market (industry, and also the consumer) will bear. Nobody should suppose that heart disease, breast cancer and colon cancer would disappear, if everybody were to cut their total fat intake from 40 per cent to 29.9 per cent of total calories. Dietary goals are figures below which (or above which) the balance of food intake is judged to be safer; rather like th~ figures above which certain levels of radioactivity are judged to be 'unsafe'.

'Diet, Nutrition and Cancer' was a stage in the development of dietary goals at least as important as 'Dietary Goals for the United States'~~~ and 'Medical Aspects of Dietary Fibre' .94 Cancers may be classified as diseases of those systems of the body in which they occur: thus, colon cancer may be classified as a disease of the digestive ~astro-intestinal) system.

Different cancers are different clinical entities, and at the same time can all be linked. They are potentially deadly diseases promoted by weakness or breakdown in the immune system, the natural defence of the body. The evidence is that the typically heavy consumption of fats in Western countries, in effect, provides nourishment for cancers, by mechanisms not yet properly understood.

Do some foods protect against cancer? 'Diet, Nutrition and Cancer' says probably, yes:

Cereals, vegetables, fruit - good

The main text of the report emphasises that much more work is needed before scientists can be reasonably sure that all or most of the protective factors in food can be isolated. The indications are that vitamins A, C and E are all protective, together with the trace element selenium (Se). Is fibre also protective? The committee:

Meanwhile, only good and no harm will come from eating more whole, fresh food. In 1985 the American Cancer Society ran a public service advertisement in major American periodicals headlined 'A defence against cancer can be cooked up in your kitchen and recommended broccoli, brussel sprouts, cabbage, carrots, spinach, tomatoes, lemons, melons, oranges, peaches and other vegetables and fruits as guards against cancers of the larynx, gullet, stomach, and colon; and wholegrain cereals, together with fresh vegetables and fruit, against cancer of the colon specifically. Eat less fat, and 'Eat healthy and be healthy' was the advertisement's message.

Recommendations such as these, which by the 1990s have become commonplace, are an enrichment of the scientific consensus. Until the 1980s almost all dietary guidelines reports focus on what is wrong with an unhealthy diet - fats, sugars, salt. In the 1980s an increasing number of reports, of which 'Medical Aspects of Dietary Fibre' and 'Diet, Nutrition and Cancer' remain outstanding examples, also emphasise what is right about a healthy diet - wholegrain bread and cereals, vegetables and fruit. And once again, as in the 1930s, the positive value of vitamins and minerals is identified.

Whether or not highly nutritious food is useful in the treatment of cancers, remains an intensely controversial area. By the time cancers have developed to the point of diagnosis, it may be too late for any treatment other than drugs and/or surgery. But there is now good reason to believe that a nourishing diet protects against cancers. The consensus that has developed can be summarised:

1. The dietary guidelines and goals designed to protect against premature suffering and death from diseases of the circulation system, diseases of the digestive system, and common cancers (where these are known or suspected to be caused in part by the Western diet), are consistent with each other.

2. Independent expert scientific reports are in close agreement, that Western food supplies and thus diets, promote a range of epidemic diseases, because they contain too much total fat, saturated fat, cholesterol (some disagreement here), added sugar, salt, and alcohol.

3. These expert reports also agree that protection against these diseases is given by a diet rich in fibre, starch, polyunsaturated (essential) fats, vitamins and minerals; and that the best sources of these nutrients are diets rich in cereals, vegetables and fruit.

4. While most expert reports do not address this issue directly, their recommendations imply that the problem with modern Western food, is that it is too often highly processed: it is poor in essential nutrients, heavy in fats and sugars.

Starting early

Also in 1982, the American Heart Association published a 'Rationale of the Diet-Heart Statement'; and in 1983 emphasised the vital importance of a healthy diet in early life, in 'Diet in the Healthy Child' which stated, for children over the age of two years, 'the use of a prudent diet, reduced in fat content, in healthy children is a safe and most likely effective way' to prevent heart attacks later in life. These two reports are updated versions of what has become the classic AHA position expressed in earlier reports: total fats down to 30 per cent of total calories; saturated fats down to below 10 per cent; dietary cholesterol down to below 300 milligrams a day; less salt; little reference (except in lay translations of the reports) to foods as distinct from nutrients; and little interest one way or the other in sugar unless combined with fat in ice-cream, cakes, biscuits. milk-shakes, and such-like foods.

The world perspective

An expert committee convened by the World Health Organisation produced 'Prevention of Coronary Heart Disease' in 1982.106 From time to time, WHO produces 'blue books' on key public health issues. These are designed to be (and usually are) profoundly influential, as the standard reference sources for health professionals throughout the world, including developing countries without the resources for expert committees of their own.

The WHO committee of twelve formed to analyse the problem of heart disease, and to make recommendations, came from Africa, Australasia, China, Finland, Germany, Israel, Sweden, the UK, the USA, and the USSR. They were joined by Professor Jeremiah Stamler and by Professor Henry Blackburn.

The Chairman of the committee, Professor Geoffrey Rose of London University, made his own position clear in a paper 'Strategy for Prevention: Lessons from Cardiovascular Disease'107 which he published in the British Medical Journal in 1981. He reproached the British medical profession:
Correspondingly, 'Prevention of Coronary Heart Disease' concluded by stating that we now know enough about the dietary causes of heart attacks to act:
In other words, everybody - not only those already identified by doctors as at high risk of heart attacks - will do well to eat more healthy food and cut down on unhealthy food. And it seems that the scientists on the committee enjoy their food. 'Prevention of Heart Disease' not only specifies foods, but also starts with a positive list:
  • Appropriately combined foods of plant origin: beans, cereal grains, vegetables (cooked and raw), and fruit (offering good-quality protein, low fat, low saturated fat, low cholesterol, low sodium, low refined sugar, high complex carbohydrates, high minerals, vitamins and fibre, and lower energy intake).

  • Fish, poultry and lean meats, used in small portions and eaten less often as the main dish (offering good-quality protein, low fat, low saturated fat, low cholesterol and lower energy intake).

  • Low fat dairy products for adults (offering good-quality proteins and minerals, low saturated fat, low cholesterol, and lower energy intake).

  • Less oils and fats in food preparation and in spreads; preference to be given to liquid vegetable oils.

    Correspondingly, the report recommends that everybody will do well to eat less fatty meat, fewer high-fat dairy products, fewer 'commercially baked products', and less alcohol. As its title indicates, the report is not only concerned with diet, and makes many other recommendations to prevent cardiovascular disease. But its emphasis on diet is impressive, and throughout the 1980s 'Prevention of Coronary Heart Disease' probably became the most influential document on its subject - certainly in those countries not already plentifully supplied with expert reports.

    Cancer and heart disease:

    consistent messages The eventual 'Consensus Statement' on diet and cancer is similar to and consistent with the emerged scientific consensus on diet and heart disease. The recommendations of the ECP/IUNS group to the general public are:

    Decrease the intake of saturated and unsaturated fat in countries where, on average, fat constitutes more than 30 per cent of total food energy (calories). In other countries, people should maintain their lower fat intake. Consumption of fat can be decreased (a) by lowering the intake of butter, margarine, cooking oil, salad oils, and dressings; (1)) by selecting fish, poultry, leaner meat products, and low-fat dairy products; and (c) by broiling, baking, and steaming foods, rather than frying.

    Eat a varied diet that contains different types of vegetables and fruits, especially green leafy and root vegetables and citrus fruits; these foods can supply an adequate intake of vitamins and minerals, so that supplements do not have to be used.

    Consume foods that are rich in complex carbohydrates (e.g. starch and fibre) that are known to promote healthy bowel function.

    Maintain appropriate body weight. If a lower energy intake is desirable, eat foods with complex carbohydrates, including whole-grain cereal products, fruits, and vegetables, instead of the higher-energy fatty foods.

    Consume a low-salt diet. A desirable goal is less than 5g of salt per day as recommended in relation to cardiovascular diseases.

    Use fresh or minimally processed foods rather than cured, pickled, or traditionally smoked foods. Do not eat mouldy foods.

    Drink alcohol in moderation, if at all.

    Industry and government are urged to collaborate in the creation of European food supplies that should lower national and international rates of illness and death from cancers.

    Presenting the findings of the Aarhus workshop at the International Congress of Nutrition held at Brighton in August 1985, before their official publication, Professor Kenneth Carroll of the University of Western Ontario, one of the workshop leaders, commented: 'If you eat food in its natural state without processing, you get a natural balance of nourishment'.215

    Health for all in Europe? The most scientifically penetrating expert report reviewed so far is 'Healthy Nutrition', commissioned by the World Health Organisation Regional Office for Europe and published in 1988.216
    wrote Jo Asvall, WHO European Regional Director, in his foreword to this 150-page hook. Superficially, despite its clear title and attractive cover with a colour photograph of a three- generation Italian family enjoying an open-air lunch, 'Healthy Nutrition' is unexciting, a dull report, stuffed with statistics and written in an oblique style. Like any new map, it takes some studying. What it amounts to is a blueprint for use by the architects of new, rational and progressive food and agriculture policies designed for the countries of the WHO European region.

    'Healthy Nutrition' is written by Professor Philip James (of the NACNE report) in collaboration with three European colleagues: Professor Anna Ferro-Luzzi from Italy, Professor Wictor Szostak from Poland, and Professor Bjorn Isaksson from Sweden. The report was drafted in 1985 and 1986; successive drafts were circulated to colleagues throughout Europe; and the final report is a synthesis of comments received. Like the NACNE report, 'Healthy Nutrition', sometimes known as 'EuroNACNE', is largely a report on reports:
    In its 'Executive Summary', the report sets out the problem and proposes a solution. In doing so the scale of its vision immediately becomes apparent:
    This is a public health statement of the utmost importance. It says in effect that there is a vast amount of suffering and premature death in Europe, from diseases of which the typical European diet is a contributory cause; and that the problem is so vast that we simply cannot wait until all the scientific answers are in before acting. By the time scientists know the exact cause of the diseases that most of us now suffer and die from, we ourselves will no doubt all be dead.

    Recommendations compared

    The agreement between 'The Surgeon General's Report on Nutrition and Health', and 'Diet and Health' is generally also striking. The main difference, is that the official Surgeon General's report stops short of specifying targets for a healthy diet, and was for this reason criticised as 'wishy-washy' by Michael Jacobson of the Centre for Science in the Public Interest. The summary recommendations of the two reports compare as follows.

    On fats and cholesterol:
    On complex carbohydrates and fibre:
    On salt:

    Reduce intake of sodium by choosing foods relatively low in sodium and limiting the amount of salt added in food preparation and at the table. [Surgeon General]. Limit daily intake of salt (sodium chloride) to 6 grams or less. Limit the use of salt in cooking and avoid adding it to food at the table. Salty, highly processed salty, salt-preserved, and salt-pickled foods should be consumed sparingly. [National Academy].

    On alcohol:
    On weight control:
    Both reports also recommend reduced sugar consumption, to avoid tooth decay; and a diet rich in calcium, especially for women. The Surgeon General's report recommends iron-rich foods for children, adolescents, and women of child-bearing age, provided that the sources of iron (and also calcium) are low in fat. The National Academy report acknowledges that many people take vitamins and/or minerals in pill form, and cautions against doses in excess of the RDA (recommended Dietary Allowance).

    Positive messages

    The main recommendations of both reports are generally harmonious not only with each other but also with those of almost all expert reports on diet and health published since the 1970s and reviewed here. Within this harmony there is a significant shift in emphasis. Reports published in the late 1980s are much more inclined to emphasise the positive value of nourishing foods, especially vegetables, fruits, and wholegrain cereals, together with lean meat, fish, and low-fat dairy products: while they repeat the standard recommendation to consume less fat, saturated fat, sugar, salt and alcohol, the stress is positive, on healthy foods, rather than negative, on unhealthy nutrients.

    There are a number of reasons for this shift. First, market research and common sense has encouraged expert committees to give positive rather than negative advice. Second, a consumer can literally grasp a cabbage, an orange, or a loaf, but does not have a feeling for (say) saturated fatty acids. Third, the message to eat more healthy foods rather than less unhealthy foods is helpful to many sections of industry and therefore also to government. Fourth, a mass of scientific evidence accumulated since the 1970s has identified the positive value of vegetables, fruit and wholegrain bread and cereals; in particular, these whole foods are rich in a combination of nutrients collectively known as 'anti-oxidants' that probably protect against cancers and also against heart disease.

    One relatively new theme emerges in 'Diet and Health': the evidence that protein of animal origin, in the quantity it is typically consumed in the USA and many other Western countries, is too much of a good thing. At least by implication, virtually all expert reports published before the late 198Os assume that protein is not a public health issue; as long as around 10 per cent of total calories is in the form of protein people will be well nourished, and anything above that figure is no problem, is the impression given. However, another mass of scientific evidence now strongly suggests that a diet high in animal protein increases the risk of cancers and heart disease. In practice, a diet high in animal protein is likely to be high in saturated fat; a diet low in animal fat will tend to be lower in animal protein. However, the National Academy cautions against any enthusiastic substitution of lean for fatty meat; indeed, it recommends that people generally should eat less meat:

    Because there are no known benefits and possibly some risks in consuming diets with a high animal protein content, the Committee recommends that protein intake not be increased to compensate for the caloric loss that would result from the recommended reduction in fat intake_ The Committee does not recommend against eating meat; rather, it recommends consuming lean meat in smaller and fewer portions than is customary in the United States.

    The importance of both reports and their recommendations was summarised by Dr Michael McGinnis in a paper published in 1989 in the American Journal of Clinical Nutrition. Dr McGinnis, Chairman of the Nutrition Policy Board of the US Government Public Health Service responsible for the Surgeon General's report, was also an ex-officio member of the National Academy's Food and Nutrition Board.

    As he points Out, the Surgeon General's report states that of the ten leading causes of death in the US, five (atherosclerosis, coronary heart disease, stroke, diabetes, and some types of cancer) are evidently caused at least in part by the typical American diet; and another three (liver cirrhosis, accidents, and suicide) are partly caused by excess drinking of alcohol. 'Although the precise proportion attributable to diet is uncertain, the eight conditions account for nearly 1.5 million of the 2.1 million total deaths in 1981'. Developing this theme, Dr McGinnis states:

    Dietary excesses and imbalances also contribute to conditions such as high blood pressure, obesity, dental diseases, osteoporosis, and gastrointestinal diseases that inflict a substantial burden of illness on society ... Illness and deaths from coronary heart disease alone cost Americans an estimated $49 billion in direct health-care costs and lost productivity in 1985, and the costs of cancer for that year were estimated at $72 billion.

    And the general conclusion, endorsed by the US Department of Health and Human Services, is:

    A reduction in intake of foods containing fat accompanied by an increase in foods containing complex carbohydrates and fibre should reduce risk not only for coronary heart disease but also for certain types of cancers, stroke, diabetes, and, perhaps, some gastrointestinal conditions. The report further emphasises that its recommendations can readily be accomplished by an overall increase in dietary intake of vegetables, fruit, beans, and grains and a choice of lean meats, poultry without skin, fish, and low-fat dairy foods.

    The politics of change

    Complete government support for a national food and nutrition policy requires backing from the departments responsible not only for health, but also for agriculture and the food industry. In the USA, the UK and other countries, the department of health can set new agendas; but the department of agriculture has influence over the national food supply, and therefore decides whether or not any agenda will be put into practice.

    Prevention begins in childhood

    Are dietary guidelines designed for everybody, or only for adults? What about children? Throughout the twentieth century, paediatricians, the physicians responsible for child health, together with the nutritionists and dieticians who work with children, have said that growing children need lots of energy (calories) from food, as well as protein; and have encouraged parents to feed their children with a so-called 'energy-dense' diet, meaning in practice, foods containing a lot of fat and added sugar.9 Go for growth! By the 1980s it was generally accepted that the right diet for children over the age of 5 is the same as that for adults; but many paediatric health workers refused to accept that the scientific consensus applies to young children under the age of 5. 144

    In contrast, physicians and health workers concerned to prevent Western diseases are increasingly sure that after weaning, children should eat much the same diet as adults. People rarely actually suffer from heart disease Until middle age; but the process that eventually leads to a heart attack begins at the beginning of life, for anybody who eats a typical Western diet. By the time heart disease is measurable or evident, it is often too late to make much difference. Increasingly, therefore, the focus on prevention of heart attacks has shifted from middle age to childhood.

    In 1983 the American Heart Association stated that its recommendations for adults apply to all healthy children over the age of 2. In 1986 the American Academy of Pediatrics, in a short report, 'Prudent Life-style for Children: Dietary Fat and Cholesterol', did not agree. Commenting on the view that children should eat a low-fat diet, the Academy said, for children of all ages:

    British children: a radical re-think

    In 1988 the UK Department of Health published a new version of its 'Present Day Practice in Infant Feeding'252 prepared by its Panel on Child Nutrition of the Committee on Medical Aspects of Food Policy. This report is the beginning of a new age for parents of young children, and for health professionals concerned with children; for it radically revises the old thinking, as published eight years previously in the first edition of 'Present Day Practice in Infant Feeding'.253 Effectively, the 1988 edition states that once babies are weaned, their diets should have the same nutritional quality as recommended in the UK for adults in the 1984 COMA report on 'Diet and Cardiovascular Disease':
    In 1984 the COMA report on 'Diet and Cardiovascular Disease' carried a warning, stating that its recommendation that consumption of total fats be cut to a maximum of 31-35 per cent of total calories and of saturated fats to a maximum of 15 per cent of total calories, applied only over the age of 5. New evidence convinced the 1988 COMA panel on Child Nutrition that children over the age of 2 should eat a lower fat diet, just like older children and adults:

    The substitution of whole cow milk by lower fat milk is not recommended for children under the age of 2 years. For children above this age, semi-skimmed milk and other reduced-fat dairy products may be introduced into the diet ... We note the inclusion, without reported harmful effects, of semi-skimmed milk in the diets of two year old children surveyed in Sweden and in Canada, and we are aware that this practice is not unknown in Britain. We endorse the recommendations in 'Diet and Cardiovascular Disease', but we consider that in the light of currently available evidence it is reasonable to introduce semi-skimmed milk into the diet of children between the ages of 2 and 5 years provided that the diet as a whole is adequate.

    In addition, 'Present Day Practice in Infant Feeding' recommends a low-sugar, low-salt diet for all babies and young children as part of the weaning process, and thereafter.

    Immediately following this official COMA report, the Coronary Prevention Group, the UK equivalent of the American Heart Association, published 'Children at Risk: Should Prevention of Coronary Heart Disease Begin in Childhood?'. The answer to the question posed in the title of this 12-page statement, is an unequivocal 'yes'.

    The Coronary Prevention Group report is concerned with children of all ages. It pointed to the fact that the diets of British schoolchildren are known to be unhealthy. A survey of over 3,000 British 11 and 14 year-olds commissioned by the Department of Health, undertaken in 1983 and initially published in 1986, had shown that around a quarter of British schoolchildren consume more than 40 per cent of their calories in the form of fats. Commenting on this for a special Granada Television World in Action programme, 'The Threatened Generation', Professor Philip James stated:
    The Coronary Prevention Group endorsed the recommendations of the COMA panel on Child Nutrition, and went further, recommending skimmed as well as semi-skimmed milk for children between the ages of 2 and 5. Furthermore:
    The final recommendations of the Coronary Prevention Group include a call for a 'national health strategy for children' to be developed by the UK Department of Health together with the Department of Education and Science; 'detailed, quantified and practical dietary guidelines' for children under 5 to be devised by the Department of Health COMA panel on Child Nutrition; revival of nutritional standards for schools catering; and major anti-smoking and pro-exercise campaigns directed at schoolchildren. The recommendations for the diets of children over the age of 2 is much the same as that of the 1988 'Present Day Practice in Infant Feeding':

    A bold Scottish line

    After Northern Ireland, Scotland also took a line on the prevention of heart disease bolder than the policy laid down in Whitehall.

    In 1979 the Scottish Home and Health Department commissioned a report from an expert committee chaired by Professor Ian Bouchier. This agreed that rates of death from coronary heart disease in Scotland are 'appalling', noted that excessive drinking of alcohol is a major public health problem in Scotland, recorded that the Scots on average consume less than half the amount of green vegetables eaten in the UK, but did not accept that action was needed to change the Scottish diet:
    The committee, mostly made up of academics, concluded that more research was needed. In 1988 the Home and Health Department set up a 'Working Group on Prevention and Health Promotion' chaired by a general practitioner, Dr Keith Davidson, mostly made up of community health workers. Their report, 'Prevention of Coronary Heart Disease in Scotland', was endorsed by Michael Forsyth, then junior Minister at the Scottish Office responsible for public health, and published with official status in April 1990.

    Referring to the 1984 COMA report, the NACNE report, and the 1988 WHO report for Europe, 'Healthy Nutrition',216 the section on 'Nutrition' begins:
    The report notes that even a 10 per cent reduction in cardiovascular diseases in Scotland would save stlg60 million a year in costs to the taxpayer for the National Health Service, and in output lost through certified incapacity to work. The savings of a 50 per cent reduction, as achieved in the USA and Australia, would be stlg300 million a year (1988-89 prices).

    A comprehensive set of recommendations for action are included in the report; a 'population strategy' is proposed, and 'detailed guidelines on nutrition, based on recent reports, should be prepared nationally and locally for each area health board'. The report ends with 'A framework for a national major reports': by this it means not only the officially recognised 1984 COMA report, but also the NACNE report and the 1988 WHO report for Europe, unrecognised in Whitehall:
    And the guidelines finish with recommendations that 'energy intake be maintained', because everybody should be more physically active; and that vitamin and mineral intakes should be those officially recommended in the UK.

    These guidelines for Scotland are a departure from Whitehall policy of the day. Insofar as they follow the 1984 COMA report, they acknowledge that everybody in Scotland is at high risk of coronary heart disease. And they accept the NACNE report's targets (short4erm, or long4erm) for consumption of sugar, salt, and fibre, while going further than NACNE for alcohol. The recommendation to switch from animal to cereal and vegetable protein acknowledges the mounting evidence showing that the old idea that animal protein is superior, has turned out to be mistaken.

    Britain: a new COMA

    At the end of 1986, the Department of Health set up another new COMA panel, on RDAs, or 'Recommended Daily Amounts'. Since the 1940s, as already mentioned, the governments of the UK, the USA, and then eventually of countries all round the world, have set official recommended levels (PDAs) for energy (calories), protein, and those vitamins and minerals reckoned to be important for public health. The purpose of such guidelines is to ensure a food supply that includes levels of these nutrients judged to be more than enough to avoid deficiency diseases.

    With rare and then only partial exceptions, RDA reports are not concerned with fat, carbohydrate (starch and sugar), fibre, salt, or alcohol. This is because when the need for vitamins and minerals was first identified, after the discovery of the vital importance of vitamins A, B, C and D as well as of the minerals calcium and iron, over-consumption was not a public health issue. Fat and carbohydrate were not seen as problems, as long as people ate enough; salt (or rather sodium, one part of salt) was identified as a mineral in plentiful supply for which an RDA was therefore not needed; fibre was not known to be relevant to human health; and alcohol was off the agenda, being consumed not as food but as drink.

    For example, the 1979 UK RDA report,121 in currency throughout the 1980s, produced by a COMA panel and accepted as an official document by government, makes no reference to the possibility that people may eat too much fat or sugar, except to say:
    Instead, detailed tabulated recommended figures for energy (calories), protein, and some vitamins and minerals, are set out. Thus, the 1979 UK COMA RDA report specifies (taking an example at random) that girls aged 7-8 should consume 1 .Omg of riboflavin (vitamin B2) every day; and this figure rises to 1.2mg aged 9-11, l.4mg aged 12-14 , and 1.7mg aged 15- 17, falling to 1.3mg for adult women.

    So the seeker after dietary guidance in the UK and in most other Western countries has been faced with two completely different types of advice. The first - dietary guidelines - make recommendations about the consumption of fat, saturated fat, sugar, salt, fibre, alcohol, other nutrients, and sometimes also types of food, in broad outline, and are designed to prevent diseases of excess or imbalance. The second - RDAs - specify requirements for energy (calories), protein, and various vitamins and minerals in minute detail, and are designed to protect against diseases of deficiency. It is no wonder hat consumers are confused, not only by conflicting advertisements produced by the food industry, but also by advice promulgated by government. Meat, cheese, eggs and milk, for example, are evidently healthy foods, judged in the context of RDAs: they contain plenty of protein and various vitamins and minerals. But dietary guidelines reports, first published just a generation after the first RDA reports, point out that meat, milk and dairy products are major sources of fat and of saturated at in the Western diet, and therefore are unhealthy foods unless eaten sparingly.

    Some enlightenment is given by the UK COMA RDA report originally commissioned in late 1986, which was eventually published in July 1991 with the unexciting title 'Dietary Reference Values for rood Energy and Nutrients for the United Kingdom'. Following the US National Academy of sciences report on 'Recommended Dietary Allowances' published eleven years previously in 1980, his is the first attempt in the UK to make an integrated set of recommendations, for fat, starch, ugar, and fibre, in a report expanded from its original brief which had been to update the 1979 report on energy (calories), protein, vitamins and minerals.

    In some respects this new COMA report, also known as the 'Dietary Reference Values' report ([)RV )r short) is admirable. In sharp contrast to other officially recognised expert reports on nutrition and public health published in the UK, it is detailed (a total of 210 pages), and includes careful references ) the scientific literature which enable the reader to follow its thinking. It is also comprehensive: The most obvious change is the range of nutrients covered. Previously COMA has considered only 10 nutrients in detail; this time the number is around 40.' These include many vitamins and minerals now known to be important to public health which have not been previously recognised as such in the UK, including vitamin B6, folic acid (or folate, another B vitamin), and various minerals and trace elements such as magnesium, potassium, zinc, selenium, and chromium. (Judgement of the merits of the DRV report's views on vitamins and minerals is outside the scope of this review.)

    be exciting feature of the DRY report is that at last, years after most other major industrialised countries had issued dietary guidelines reports about fat, saturated fat, starch, sugar, fibre, and salt, ie official UK Committee on Medical Aspects of Food Policy did likewise. Indeed, the DRY report oes further, and specifies 'reference values' with figures for all these nutrients. Previewing the report an excited cover feature in 'New Scientist' commented:271
    Given the status of the Committee on Medical Aspects of Food Policy, it is fair to say that the DRY report marks an official change of heart. After a decade and more of pressure from the scientific community, other health professionals, consumer groups, environmentalists, and indeed key sectors of the food industry, the UK Government has finally recognised that the national diet amounts to a major public health problem. In setting 'reference values', the expert panel makes specific reference to coronary heart disease, high blood pressure, other diseases of the circulation system, cancers including of the breast and colon, obesity, digestive diseases and disorders, and tooth decay. While the report is cautious, frequently emphasising that evidence is incomplete and that more research is needed, it nevertheless reaches conclusions.

    Thus, while 'only about 5 per cent of adults in the UK currently derive 10 per cent of energy or less from saturated fatty acids' the report proposes that:
    While this recommendation is complicated by a further proposal that not more than a further 2 per cent of energy be derived from trans fatty acids, which are chemically like polyunsaturates but from the health point of view are like saturates, the 1991 COMA recommendation is rather more radical than that of the 1984 COMA panel on 'Diet and Cardiovascular Disease', which recommended a maximum of 15 per cent of energy from saturated fat.

    Again, while 'total sugars, at 99 grams per person per day, contributed 16 per cent of energy' on average in the UK, the report points out that in societies where the total amount of sugar in the food supply is less than 10 per cent of energy, tooth decay is rare. Sugar in natural form, as in fruit, is h&mless: but 'non-milk extrinsic sugars', notably sucrose and glucose purchased as such or else eaten in processed foods, are harmful in the quantities consumed in the UK. The report proposes that:
    Furthermore, 'The panel agreed that carbohydrate should provide the major food energy requirement for UK populations', and it makes recommendations for consumption of foods rich in starch and fibre that are in effect much the same as those included in the NACNE report,119 and in the 1988 World Health Organisation report for Europe, 'Healthy Nutrition' In 1991, therefore, an official UK expert report at last made recommendations in line with the world-wide scientific consensus on food, nutrition and public health.

    Dietary recommendations for the world

    It was in this context that the World Health Organisation convened a study group of leading nutritional scientists, who met in Geneva on 6 - 13 March 1989. Members of the group came from Africa, Australia, Canada, China, India, Italy, Japan, the UK, the USA and the USSR. Professor Philip James from the UK, previously chief author of the 1983 NACNE report and of the 1988 WHO report for Europe, 'Healthy Nutrition', was appointed chairman of the study group.

    Its brief was to: 287
    That is to say, Professor James and his colleagues were charged not only to compile an expert report on dietary guidelines for everyone in the world, but also in effect to devise a global blueprint for the improvement of public health by means of good food. The resulting report, 'Diet, Nutrition, and the Prevention of Chronic Diseases'287 was published by WHO late in 1990; it is the one hundredth of the 100 expert reports to be analysed in this review. Its scope is outlined in an 'Executive Summary' published by the WHO Secretariat in Geneva, designed to accompany the report and to explain its purpose:
    Professor James and his colleagues were supported in their work by representatives of international organisations, such as the UN Food and Agriculture Organisation, the International Diabetes Federation, the World Hypertension League, and the International Union Against Cancer. 'Diet, Nutrition, and the Prevention of Chronic Diseases', while basing its conclusions and recommendations on the latest scientific evidence, is also built on the work done by others: it includes summaries of the findings of over 50 other expert reports (almost all of which are reviewed here and analysed in Annex One).

    Previously, scientists concerned with the public health problems caused by dietary deficiency, had worked and thought separately from scientists concerned with the public health problems caused by imbalance and excess. What, after all, do the nutritional needs of a starving child in Africa have in common with those of an obese adult in America? But one of the key achievements of the 1990 WHO report is that it sets goals expressed as ranges of nutrients, designed to work both for developing and developed countries. In the words of the Executive Summary:
    The central thesis of the 1990 WHO report is good news for everybody, everywhere. It is that the diet most likely to prevent a great range of chronic diseases, including overweight and obesity, and to promote general good health throughout life, is the same diet the world over: for men, women and children.

    A healthy diet has infinite variety. Traditional cuisines throughout the world are healthy, provided that simple meals based on starchy staples together with vegetables and fruit are eaten from day to day, and that more elaborate meals including substantial amounts of fat, sugar - and alcohol - are consumed only as occasional feasts. Key advice is always to prefer 'nutrient-dense' to 'energy-dense' foods. Again, in the words of the Executive Summary:
    The 1990 WHO report is altogether more radical then any other expert report reviewed here. The goals it sets for total fat consumption, are between 15 and 30 per cent of total energy (calories); and for saturated fat, between 0 and 10 per cent:
    The goals set for polyunsaturated fats are between 3 and 7 per cent of total energy, reflecting the view held by most scientists outside the USA that a goal of 10 per cent is too enthusiastic.

    The sharpest possible contrast is drawn between complex carbohydrates, contained in grains and other starchy foods, legumes and vegetables, on the one hand, and on the other hand 'free sugars', which is to say refined or extrinsic sugar. 'The intent is to maximise the intake of complex carbohydrate and minimise the intake of free sugars.' The goals set are: complex carbohydrates, between 50 and 70 per cent of total energy (calories); free sugars, between 0 and 10 per cent.
    Also the report sets a target, for fruits and vegetables: a minimum of 400 grams, or just under a pound, a day:
    In other words, for all practical purposes, the more vegetables and fruits everybody eats, the better. The goal set for dietary fibre, is between 27 and 40 grams a day; for salt, an upper limit of 6 grams day; for dietary cholesterol, between 0-300 milligrams a day; and alcohol is not recommended. That sort of diet is implied by these 1990 WHO goals? The Executive Summary states:

    How to create change to healthy diets? The 1990 WHO report is a political as well as a scientific report, and its proposals, in compressed language, are awesome:

    The vision is comparable with that of John Boyd Orr over half a century previously, in his 'Food Health and Income':217

    'Diet, Nutrition and the Prevention of Chronic Diseases' sets out a political and economic agenda, including a 22-point plan addressed to the World Health Organisation, and to national governments:

    In the UK, Consumers' Association, funded solely from the subscriptions of almost one million members, convened a 'Healthy Eating Campaign' early in 1990, to promulgate the WHO report at its British launch in the Houses of Parliament in April 1991. Dr John Beishon, Chief Executive of Consumers' Association, had this to say: 289

    The Guild of Food Writers, the professional association of food writers in the UK, produced a booklet, 'Eat Well ... Live Well!' to accompany the WHO report, designed to translate its scientific recommendations about diet and disease into plain-language recommendations about food and health for everybody in the UK. In this 16-page, large-format booklet, all foods are divided into three groups. First, vegetables, salads and fruits with the headline 'Eat as much as you want.. and stay healthy'. Summarised, the story here is:

    Second, bread, potatoes and cereals, whose headline is 'Satisfy the heartiest appetite...and stay slim!'. Here, the message is:

    Third, meat, fish and dairy foods, whose headline is 'Choose for quality.. .and protect your health'. Here, 'quality' means lean meat and low-fat dairy products.

    The message is:

    And snacks and meals? 'By putting together the foods from these three groups, you can make healthy and delicious meals and snacks. Vegetarians and vegans can simply leave out the last group as appropriate.' Finally, 'Seven steps to healthy eating', following the nutritional principles of the WHO report, are set out:

    William Waldergrave, UK Secretary of State for Health, was evidently impressed. At the 9th July 1991 launch of the COMA DRV report, he acknowledged that the scientific recommendations of the report had to be translated into plain language in order to impress the British people, saying:
    There's a huge piblic education and transmission and translation job now to be done .... There are some very good private sector and voluntary organisation campaigns going on , too.
    And as he spoke, he held up a copy of 'Eat Well ...... Live Well!'.

    Published in 1992 by:

    Consumers' Association Ltd and Geoffrey Cannon

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