Beneficial effects on lipids and the haemostatic system

Oily fish contains large quantities of the long chain n-3 ((omega)-3) polyunsaturated fatty acids (eicosapentaenoic acid (C20:5) and docosahexaenoic acid (C22:6)). Low rates of coronary heart disease in various populations with high intakes of fish suggested health preserving effects of these fatty acids. For example, mortality from coronary heart disease was found to be low among Greenland Inuits who ate large amounts of fish and whale meat (400-500 g/day, 14 g n-3 fatty acids/day)1 and in Japanese fish eaters.2 In the Netherlands 30 g of fish daily was associated with 50% fewer deaths from coronary heart disease.3 In the multiple risk factor intervention trial cardiovascular mortality was inversely proportional to the intake of n-3 fatty acids over the 10.5 years of follow up.4 Not all investigators, however, have confirmed these findings.5 6

Suggested mechanisms for this cardioprotective effect focused first on serum lipids.7 In healthy subjects increased consumption of long chain n-3 fatty acids is associated with falls in serum concentrations of triglycerides and very low density lipoprotein8 9; cholesterol concentration …