Moderate fish oil intake improves lipemic response to a standard fat meal: A study in 25 healthy men

Abstract

To test the hypothesis that conditioning with a practical dose of fish oil will reduce postprandial lipemia, 25 healthy men were matched according to levels of fasting plasma triacylglyceride and allocated to 6 weeks of either fish oil or olive oil supplements (5 g/day). After a 12-hour overnight fast at the termination of the study period, the subjects were given a standard test meal containing 89% of energy as fat (0.73 g fat/kg body wt, polyunsaturated to saturated fat ratio=0.4). Vitamin A (429 retinol equivalents/kg body wt) was included to endogenously label the chylomicrons. Venous blood samples were obtained before the test meal and hourly thereafter for 8 hours. Chylomicrons were separated by ultracentrifugation, plasma triacylglyceride concentration was determined enzymatically, and retinyl ester levels were measured by liquid chromatography. Postprandially, the fish oil-fed group exhibited mean total and chylomicron triacylglyceride concentrations that were significantly (p<0.05) less than those of the olive oil-fed group. Both the fish oil- and olive oil-fed groups had similar rises in chylomicron retinyl esters during the first 2 hours, but after this time the postprandial response of the fish oil-fed group was consistently and significantly (p<0.05) less than the response of the olive oil-fed group. Our results suggest that improvement in lipemic response, whether due to enhanced chylomicron clearance or decreased chylomicron entry into the plasma pool, can be achieved at a much lower intake of fish oil than previously reported.