Alpha-linolenic acid and cardiovascular diseases.

The intake of saturated fat was postulated to be the main environmental factor for coronary heart disease. It was also postulated that the noxious effects of saturated fatty acids (FA) was primarily through the increase in serum cholesterol. Nevertheless intervention trials either in coronary patients or even in primary prevention did not observe significant reduction in cardiac mortality, especially sudden death, when the diet was markedly enriched in linoleic acid (LA), the most efficient FA to lower serum cholesterol. In intervention trials, It is only when the diet was enriched in n-3 FA, especially alphalinolenic acid (ALA) that cardiac death was reduced. Studies in animals as well as in vitro on myocytes in culture, have shown that ALA was preventing ventricular fibrillation, the chief mechanism of cardiac death. Furthermore, studies in rats have observed that among n-3 FA, ALA, the precursor of the n-3 family, may be more efficient to prevent ventricular fibrillation than eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In addition it was demonstrated that ALA was the main FA lowering platelet aggregation, an important step in thrombosis, i. e. non fatal myocardial infarction and stroke. Thus, without side effects, a higher intake of ALA (2g / day) with a ratio of 5/1 for LA/ALA, could possibly constitute a nutritional answer to the main cause of morbidity and mortality in industrialized countries.