EFFECTS OF DIETARY-FAT CONTENT, SATURATED FATTY-ACIDS, AND FISH-OIL ON EICOSANOID PRODUCTION AND HEMOSTATIC PARAMETERS IN NORMAL MEN

Populations that consume a diet rich in marine lipids have been report ed to have a lower risk of coronary heart disease. However, some Weste rn population groups with a high fish consumption continue to suffer e levated rates of coronary heart disease. Many of these individuals con sume a diet rich in saturated fats in addition to the fish. To examine these possible dietary interactions we fed six healthy men diets that contained two revels of saturated fat (5% and 19% of energy). During 3-week periods the study subjects were given diets with a low-(25% of energy) and high-(39% of energy) fat content with and without inclusio n of n-3 polyunsaturated or monounsaturated fatty acids (2% of energy) . The effects of the n-3 fatty acids on the principal plasma lipid fra ctions were similar regardless of the saturated fat intake. Platelet f unction, as measured by the skin bleeding time, was inhibited when n-3 fatty acids were added to the low saturated-fat diet. In vivo thrombo xane A(2) production as assessed by urinary metabolites also declined (p < 0.01) during supplementation with n-3 fatty acids to a low-fat di et. Prostacyclin production were reduced on a low-fat diet compared to a high-fat diet regardless of supplementation with n-3 fatty acids. N -3 fatty acids stimulated the synthesis of modest amounts of thromboxa ne A(3) and prostacyclin I-3, on both the low and high saturated-fat d iets. These studies showed that the effects of eicosapentaenoic and do cosahexaenoic acids on platelet and vascular function and eicosanoid p roduction are modulated by the content of saturated fatty acids in the diet. A diet with a low amount of dietary fats supplemented with n-3 fatty acids most favorably affected platelet function and platelet vas cular interactions.