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) positi ons of fish-oil triacylglycerols influenced their respective incorpora tion into triacylglycerol, cholesterol esters, and phospholipids of tw o lipoprotein fractions: low- and very-low-density lipoprotein (VL/LDL ) and high-density lipoprotein (HDL). Nine healthy volunteers were stu died 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 1 1 g fish-oil triacylglycerol in which DHA was predominantly situated i n the sn-2 position. Our results strongly suggest that the higher tria cylglycerol 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 importa nt role of the triacylglycerol structure and its potential manipulatio n for modulating availability of either or both fatty acids.