Petr Skrabanek was professor of medicine at Trinity College Dublin who according to his obituary in The Times:
“exposed the claims of public health doctors, epidemiologists, dietary evangelists and others that many diseases were preventable. This was not a popular message and he evoked strong antipathy in certain circles which was more than offset by the respect of his many admirers around the world.” (1).
Critique of dietary guidelines
I have just come across a pamphlet entitled “Death of Humane Medicine”, which he wrote that has some very pertinent comments on the formulation and use of the dietary guidelines. Here are some extracts:
- “In the 1930s and 1940s, a high fat diet was still recommended by the medical profession as the diet for health. But from about 1950 onwards, dairy fats and meat became suspect as the cause of heart disease, although as late as 1966 the National Academy of Sciences and the National Research Council in the USA, in their report on dietary fats and health, could still maintain that there was not enough evidence of benefit from dramatically reduced fat consumption and they expressed concern that such a change could have ‘unpredictable, possibly deleterious effects’. There has been no new evidence since 1966 to reverse this wise counsel, but what has changed since is the readiness of various expert committees to issue guidelines which are not supported by evidence and often in conflict with it.”
- “Thus, for example, in 1970, a group of American experts, led by the indefatigable anticholesterol campaigner, Jeremiah Stamler, issued specific guidelines for all Americans, including infants, pregnant mothers and the elderly, exhorting them to avoid butter, egg yolk, bacon, lard and suet. Suddenly all food became divided into ‘good’ and the ‘bad’, ‘healthy’ and ‘unhealthy’. These guidelines were adopted by the American Medical Association, in the absence of any evidence that such a diet would prolong life. One of the critics pointed out that these recommendations of major dietary changes, with wasteful neglect of nutritious foods, such as butter, eggs, whole milk, cheeses and beef borders on irresponsibility and smacks of medical quackery.”
- “Oster predicted, correctly, that:
“The scare technique employed by the apostles of lowering serum cholesterol will create hypochondriacs who are afraid to eat wholesome food.”
- “In 1976, the British Royal College of Physicians and the British Cardiac Society followed the American example of dietary dirigism and issued more or less identical guidelines for Britons. One of the recommendations was to reduce fat consumption to 35 per cent of total energy intake. There was no justification for this figure, since in the so-called Seven Countries Study, which until then was the main prop of the lipid-heart hypothesis and which was thought (erroneously) to provide evidence for cholesterol as the villain, countries with the lowest incidence of heart disease, such as Crete, had a total fat intake of 40 per cent, which was the same as in the UK. In the Netherlands, which had one of the highest life expectancies in Europe, the percentage of total energy derived from fat was a staggering 48 per cent, while among the Masai of East Africa, whose diet consisted of 66 per cent of calories as fat, blood cholesterol was extremely low and atherosclerosis rare.”
- “Similarly, the recommendation by countless committees to increase the consumption of polyunsaturated fats to 10 per cent, was not supported by any available evidence for its health-promoting effects. On the contrary, polyunsaturated fatty acids are potentially carcinogenic when used in excess, and in the Seven Countries Study the lowest rates of heart disease were recorded in populations who used only three to seven per cent of polyunsaturated fats. Moreover, to reduce fat consumption from the current level of about 40 per cent down to 30-35 per cent (or as some enthusiasts propose, to 25 per cent) would mean to go back to the levels of fat intake in the Glasgow slums half a century earlier. It was then that the medical profession urged the population to eat more butter, eggs and meat and to drink plenty of milk.”
- “By the end of the 1980s, the general formula, adopted by ‘consensus’ committees around the world, for a ‘correct’ diet was: fat down to 30 per cent, comprising an equal ratio of saturated, monounsaturated and polyunsaturated fats, cholesterol intake less than 300 mg a day, salt intake down to three grammes a day. The magic number of 3′ is reminiscent of Grimm’s fairytales. These recommendations were adopted and promulgated without any evidence from population studies that such a diet was beneficial. As pointed out by Ahrens, the only studies available at that time (the Los Angeles Veterans trial and the Finnish mental hospital trial) which, incidentally, failed to show any benefit, used different kinds of diet. Thus the proponents of the new diet were apparently ‘willing to advocate an untested diet to the nation on the basis of suggestive evidence obtained in tests of a different diet’. However, the Select Committee of the US Senate on Nutrition and Human Needs was too prestigious a body for ordinary people (or even for ordinary physicians) to question and their report, Dietary Goals for the United States, has become a blueprint for other countries to follow.”
- “One of the rare critics of the report of the Select Committee was Alfred Harper who complained that the recommendations drew unwarranted conclusions from insufficient and inappropriate research, and compared the guidelines with other food advice given by cranks and faddists, who use their magical thinking to promise a panacea for diseases which they do not understand. Harper, a distinguished professor of biochemistry and nutrition, was puzzled how the same diet could be recommended to all Americans, ‘irrespective of the nature of their health problems or whether they were ill or well’.”
- A critical examination of the lipid-heart hypothesis reveals numerous uncertainties and discrepancies, including the failure to demonstrate first that the recommended diet will significantly reduce blood cholesterol; secondly, the risk of cardiovascular disease can be lowered by reducing blood cholesterol levels; and thirdly, the proposed diet is free from any long-term adverse effects.
- “An example of confused thinking about the diet-heart hypothesis was provided by the National Institutes of Health Consensus Conference on Lowering Blood Cholesterol and in an accompanying editorial.
Causes of heart disease not known
On the one hand the editorialist admitted that:
‘It needs to be recognised that we do not [emphasis in original] yet know the cause(s) of atherosclerosis [and that] it is difficult to accept on purely scientific grounds that there is conclusive proof of efficacy of reduction of mild to moderate hypercholesterolemia.’
He then opted for the consensus that:
‘the fat content of your diet should constitute no more than 30 per cent (or even 20 per cent) of the total caloric intake. The saturated fat intake must be less than 10 per cent (or even 6 per cent or 8 per cent)’. The consensus experts, on the other hand, had ‘no doubt that appropriate changes in our diet would reduce cholesterol levels’, and that such changes
‘will afford significant protection against coronary heart disease’;
such a diet
‘should be available to all family members except those younger than 2 years’.
In other words, in the absence of scientific evidence the experts had no doubts that ‘consensus’ could fill the gap, since they could not entertain the possibility that the wishful thinking of so many was not a representation of reality.”
- “Philip Payne, Head of the Department of Human Nutrition at the London School of Hygiene and Tropical Medicine, said in a lecture that he would personally ignore such recommendations as
‘gratuitous advice, at best over-zealous and at worst impertinent’,
but he worried about the harm such advice could cause to the general public, who might become anxious about what they ate, without being able to examine the scientific content of such advice. It was a moot point, according to Payne, as to whether the dietary activists wanted
‘our compliance regardless of the benefit or perhaps yet another way of making the public more dependent on “caring” professions?’.”
- “The major dietary unthink tanks in Britain are known under the aliases of NACNE (National Advisory Council on Nutrition Education) and COMA (Committee on Medical Aspects of Food Policy). NACNE stated in their document (‘not intended for the general public’, but promptly released) that
‘heart disease can be prevented by a reduction of total fat in the diet to 30-35 per cent of total energy’.
Evidence falls short of proof
No evidence for this statement was provided as none existed. A year later, COMA, reiterating NACNE’s views, inserted a curious sentence in their preamble: ‘the evidence [for the relationship between diet and cardio-vascular disease] falls short of proof’. This is correct, as no proof existed, but that did not stop the Committee making recommendations for the whole population over the age of five. A rather interesting deviation in both the COMA and NACNE reports was their cavalier attitude to egg consumption. This was subsequently rectified.”
- “Sir Kenneth Blaxter pointed out that COMA guidelines were not scientifically defensible, though apparently politically expedient, as there was ‘no rational basis for the conclusion that the diet of the population should be modified to change its fatty acid composition’.”
This pamphlet was published in 1994. Although it did not have any impact on policy, there is no doubt that the author has been totally vindicated by what has happened subsequently. The vilification of fat has definitely been one of the major reasons why there has been an increase in the proportion of carbohydrates in the diet, which has contributed to the increased incidence of diabetes and obesity. In fact, the outcome is probably much worse than was anticipated by critics such as Petr Skrabanek. This episode emphasises how important it is that if any advice is promoted to the public generally, it is imperative that it is soundly based on convincing evidence that it will be beneficial. Even then we are faced with the practical reality that the information will be distorted and manipulated by various vested interests. Perhaps the only sensible way forward is for individuals to accept responsibility for their own personal health with minimum reliance on the governments and healthcare professionals.
- The Times (1994). 27th June