Saturated fatty acids contribute essentially to atherogenesis, especially to coronary artery disease. In contrast, the protective effect of monounsaturated fatty acids such as oleic acid, contained in olive oil and as a constituent of a Mediterranean diet is very well shown epidemiologically.

There is a modest beneficial effect on the clinical manifestation of coronary heart disease when saturated fatty acids of animal provenience are partially replaced by omega 6 fatty acids (linoleic acid). However, studies with the addition of omega-3-fatty acids in the diet (fish oil rich in eicosapentaenoic and docosaexaenoic acid and rape seed oil rich in alpha linolenic acid) demonstrate a significant decrease of sudden cardiac death and non fatal myocardial infarction.

Long-chain omega-3-fatty acids have a direct antiarrhythmic effect on myocytes. The reduction of non-fatal myocardial infarctions during consumption of diets rich in long chain omega-3-fatty acids could at least in part be attributed to inhibitory effects on platelet aggregation and thus on thrombus formation and to a stabilization of atherosclerotic plaques.