Letters: Not another helping of diet advice

JEREMY LAURANCE's article "Fed up with bad advice" (Real Life, 24 January) is surely a dangerously misleading grumble around recent research on aspects of diet - in format, and here and there in content, too.

Fat: the World Health Organisation's survey of 150,000 heart attacks "found that heart disease is declining everywhere, but at very different rates in different countries. This cannot be explained by changes in the traditional risk factors of smoking, blood pressure and cholesterol." Why on earth not? Smoking is declining (dramatically so in the USA) and the first thing that has to be acknowledged about cholesterol is that dietary intake is not as important as the liver's own output, and that can increasingly be managed by cholesterol-reducing drugs. And isn't it accepted that Scotland and the North do "eat a fattier diet than the rest of us"?

Vitamins: what can one make of an article headed by a large picture of assorted vegetables that has the text beneath: "Vitamins were necessary when diets were deficient of fruit and vegetables... Now research has shown that high doses can themselves be toxic", without making it clear that toxic effects are only in question in the case of synthetic vitamin products. The article does end with a final paragraph in praise of fruit and vegetables, but how many readers might have missed this?

The author mentions the Caret study which revealed 28 per cent more cancers and 17 per cent higher death rate in a group taking synthetic beta-carotene, but without mentioning either that the entire study was of high-risk smokers, or that it failed to isolate the effect of high alcohol consumption. On vitamin C, he mentions the Leicester University study reported in Nature but without adding that the oxidative damage was more than balanced by the anti-oxidant effects, to the extent that the authors of the study, in their September reply to correspondence, concluded "...and hence our study shows an overall profound protective effect of this vitamin".

LC LAMING

Imperial College, London SW7