The controversial view is included in a critical analysis of current dietary guidelines which have been accepted on the strength of 'consensus unsupported by scientific evidence, and sometimes in opposition to it', the report says. These consensus views have been reinforced by 'militantly concerned' health promoters.
The report claims that the dietary changes adopted so far have been 'trivial' and do not explain changes such as a 50 per cent fall in heart disease in Western society in the last 20 years.
The World Health Organisation, which meets today in Geneva to discuss global dietary guidelines, is condemned in the report from the Social Affairs Unit, for providing advice that is 'irrelevant and impractical'. The Government's targets for dietary change in the United Kingdom are also dismissed as being 'meaningless and notional'.
Professor Mike Gibney, chairman of the EC working group on nutrition, and one of three independent contributors to the report, argues that 'even if small changes to . . . diet were beneficial, the full effect of the benefit is, in the complex scale of heart and cancer disease aetiology, likely to be small'. Much of the consensus is based on shifting fashions.
Dr Petr Skrabanek, a community health specialist, says that the knowledge on which most dietary advice is formulated is weak.
He sees no justification for cutting fat intake to 35 per cent of the total energy intake. 'Countries with the lowest incidence of heart disease, such as Crete, have a total fat intake of 40 per cent,' he says. 'In the Netherlands, with the highest life expectancy in Europe, the percentage of total energy derived from fat is . . . 48 per cent.'
Dr Skrabanek writes that levels of blood cholesterol have no predictive value for future heart attacks, and that lowering levels through diet or drugs has no overall effect on mortality - although it may increase the risk of cancer. Dr James Le Fanu, a general practitioner and one of the first doctors to challenge the dietary theory of heart disease, says that with static fat consumption, coronary heart disease has fallen by 50 per cent, and with little change in salt consumption, the incidence of strokes has fallen similarly. However, a moderate increase in fibre has had no impact on colon cancer or other diseases. 'There seems little alternative other than to conclude that dietary guidelines are impractical,' he says.
Professor Desmond Julian, medical director of the British Heart Foundation, said yesterday that 'excessive claims' had been made by both sides in the debate and the authors of the report were as guilty as those they criticised.
'There is an element of truth in what they are saying and an element of ignoring basic scientific evidence. To say that cholesterol levels are not a predictor of future heart attacks is untrue and there is solid evidence to show that.'
There is still a lot to be learnt about cholesterol and until large- scale clinical trials are completed there is no definitive proof of its significance in heart disease, Professor Julian said. 'We have suffered from extremists on both sides of the fence. Now it is time for a little common sense.'
Who needs WHO?, by the Social Affairs Unit, 75 Davies Street, London, W1Y 1FA; pounds 5