DIFFERENTIAL INCORPORATION OF FISH-OIL EICOSAPENTAENOATE AND DOCOSAHEXAENOATE INTO LIPIDS OF LIPOPROTEIN FRACTIONS AS RELATED TO THEIR GLYCERYL ESTERIFICATION - A SHORT-TERM (POSTPRANDIAL) AND LONG-TERM STUDY IN HEALTHY HUMANS

We investigated how the distribution of eicosapentaenoate (EPA, 20:5n-3) and docosahexaenoate (DHA, 22: 6n-3) in the sn-2 and sn-1(3) positions of fish-oil triacylglycerols influenced their respective incorporation into triacylglycerol, cholesterol esters, and phospholipids of two lipoprotein fractions: low- and very-low-density lipoprotein (VL/LDL) and high-density lipoprotein (HDL). Nine healthy volunteers were studied over both a shea-term (0-8 h) and a long-term (30 d) postprandial period of daily supplementation with 2 g EPA and 1.3 g DHA given as 11 g fish-oil triacylglycerol in which DHA was predominantly situated in the sn-2 position. Our results strongly suggest that the higher triacylglycerol incorporation of DHA and the higher metabolic availability of EPA compared with DHA for phospholipid accumulation (particularly in the short-term study) depend on their respective preferential sn-2/sn-1(3) positions in fish-oil triacylglycerol, emphasizing the important role of the triacylglycerol structure and its potential manipulation for modulating availability of either or both fatty acids.