[Atheroma and fish oils]

Abstract

The reduction in cardiovascular mortality and morbidity observed over the last decade may be considered to be largely the result of the prevention of lipid disorders. The beneficial effects of diet and increased consumption of unsaturated fatty acids on ischaemic heart disease is a generally accepted concept. The low death rate from coronary artery disease amongst Greenland eskimos who eat a lot of fish has been confirmed by epidemiological studies of other large fish eating populations like the Japanese. The results reported by Bang and Dyerberg have been confirmed by the Zutphen study undertaken by Kromhout in the Netherlands. Fish oil act by the intermediary of the omega-3 fatty acids. Fish oil is rich in high unsaturated omega-3 fatty acids, the most important one being eicosapentaenoic (EPA) and docosahexaenoic acids (DHA). On the basis of epidemiological studies and clinical and experimental observations, it would appear that the consumption of marine polyunsaturated fatty acids has at least a preventive effect on phenomena of atherosclerosis and thrombosis. Their efficacy on the regression or stabilisation of the atheromatous plaque has not been demonstrated. The sites of action are multiple: decreased platelet aggregation; inhibition of thromboxane A2 production; reduction of triglyceride and VLDL concentration; improved blood rheology; action on the endothelium and proliferation of the intimal cells, vascular tone and vasomotricity. The importance of cardiovascular mortality and the hopes raised by clinical and epidemiological trials justify the pursuit of complementary studies on the efficacy and modes of action of marine polyunsaturated omega-3 fatty acids.