Dose-response relationships in blood lipids during moderate freshwater fish diet

Fish and fish oils are known to counteract coronary heart disease risk factors. We have previously showed that eating moderate amounts of freshwater fish modifies lipid and prostanoid metabolism in healthy students. In this study, the dose response relationship was clarified. One hundred male students took part and were randomly divided into control and four fish diet groups with different fish diets. Hematological, serum lipid and vitamin E and A analyses were performed. Already 1.5 fish containing meals per week increased n-3 to n-6 ratio of fatty acids in erythrocyte ghost phosphatidylethanolamine. The serum triglyceride and apolipoprotein B concentration fell significantly in the group eating 3.8 fish containing meals a week for 12 weeks. At two lower doses (1.5 and 2.3 meals/week) the tendency to lower values was already seen. No significant changes were observed in the serum cholesterol, apolipoprotein A1 and vitamin E and A concentrations. The hematological variables also remained unchanged. The results show that moderate amounts of fish as a constituent of normal diet have beneficial effects on lipid metabolism.