Boreal freshwater fish diet modifies the plasma lipids and prostanoids and membrane fatty acids in man

Abstract

The effect of fish diet on 43 healthy male students was studied. They ate a fish-containing meal for 15 weeks on an average of 3.7 times per week. Twenty-one of them voluntarily restricted their lipid intake while the rest ate normally. Controls continued their usual eating habits (19 students). The meals consisted of Finnish freshwater fish (87%) (vendace, pike, perch and rainbow trout) and brackish water fish (13%) (Baltic herring) that provided about 1 g of omega-3 polyunsaturated fatty acids per day (0.25 g eicosapentaenoic acid and 0.55 g docosahexaenoic acid). During the diet, omega-3 fatty acids increased in erythrocyte ghosts and platelets at the expense of omega-6 fatty acids. The concentration of serum cholesterol diminished in those fish consumers who lowered their lipid intake. Apolipoprotein A1 and B were lowered in both fish-consuming groups. Triglyceride levels also showed a tendency to decrease. The formation of thromboxane B2 during incubation of whole blood decreased in both fish-consuming groups. The decrease of plasma 6-keto-PGF1 alpha was not statistically significant, if compared with the controls. The results obtained indicate that a moderate intake of fish-containing meals has some beneficial effects on the plasma lipid and prostanoid metabolism, when coronary heart disease risk factors are considered.