Ischaemic heart disease, serum lipids and platelets in Norwegian populations with traditionally low or high fish consumption.

In an inland and a coastal community, mortality from coronary heart disease (CHD) was registered over a 10-year period. Healthy males representing these two communities were investigated. A dietary registration showed a high saturated fat intake and a daily consumption of fish of 132.4 and 55.1 g and 0.9 and 0.2 g of eicosapentaenoic acid (EPA), in the two groups respectively. The contents of n-3 fatty acids in platelet phospholipids and primary bleeding times were similar, but collagen-induced platelet aggregation was higher in the coastal area. Higher serum triglyceride levels, higher content of saturated fatty acids and lower content of linoleic acid in platelet phospholipids were observed in males from the coastal area. CHD mortality was higher in the coastal area for both sexes. Daily dietary supplement of cod liver oil prolonged the bleeding time, reduced n-6 and increased n-3 fatty acids of platelet phospholipids. This studies indicate that a high content of lean fish and diet rich in saturated fat is not sufficient to prevent CHD.