THE INCORPORATION OF N-3 POLYUNSATURATED FATTY-ACIDS INTO PLASMA-LIPID AND LIPOPROTEIN FRACTIONS IN THE POSTPRANDIAL PHASE IN HEALTHY-VOLUNTEERS

Objective: To examine the movement of long-chain polyunsaturated n-3 f atty acids across plasma lipoprotein fractions in the postprandial pha se. Design: Eight healthy volunteers ingested a test meal (% energy: p rotein 11, carbohydrate 16, fat 73) after an overnight fast where fish oil provided the sole fat source. Blood samples were taken at baselin e and at hourly intervals thereafter for 12 h. Blood lipoprotein fract ions were separated and analysed for triacylglycerol fatty acid compos itions. These were also determined in non-esterified fatty acid and ph ospholipid fractions. Results: All n-3 polyunsaturated fatty acids acc umulated in all plasma lipoprotein fractions and in non-esterified fat ty acids. The ratios of concentrations of docosahexaenoic acid (DHA) t o eicosahexaenoic acid (EHA) were higher in chylomicrons (1.4 +/- 0.4) than in very low density lipoproteins (0.9 +/- 0.5) and particularly higher than in the non-esterified fatty acid fractions (0.8 +/- 0.4). The level of eicosapentaenoic acid (EPA) rose significantly in plasma phospholipids while that of docosahexaenoic acid (DHA) did not. Conclu sions: All n-3 polyunsaturated fatty acids are rapidly incorporated in to all plasma lipid fractions with the exception of uptake of DHA into plasma phospholipids. There is a clear tendency for EPA and DHA to pa rtition differently into the different plasma lipid fractions. Sponsor ship: Flora Nutrition Award and Nutriscan Ltd.