Dietary lipids and their relation to ischaemic heart disease: from epidemiology to prevention

From the Seven Countries Study and recent statistics from WHO and the OECD, it is clear that saturated fats, mainly dairy fats, are closely associated with the mortality rate from ischaemic heart disease (IHD). Consumption of alcohol, especially wine, but not polyunsaturated fats, seem to offer protection. Racial and other environmental factors do not seem to be confounding factors for that relationship as evaluated by studies in migrants, Japanese to USA, Southern Europeans to Australia, and in vegetarians in California. By contrast, very few trials using dietary polyunsaturated/saturated (P/S) ratios from 1.5-2.5 vs 0.4-0.7 have really prevented coronary death by diet modification. The only successful trial had a P/S ratio of 0.7. High P/S ratio increases platelet reactivity. Recent studies indicate that thrombosis and platelets play a more prominent role in IHD than expected. To decrease platelet activity and prevent IHD, a P/S ratio of 0.4-0.7 should be preferred.