DOCOSAHEXAENOIC AND EICOSAPENTAENOIC ACIDS IN PLASMA PHOSPHOLIPIDS ARE DIVERGENTLY ASSOCIATED WITH HIGH-DENSITY-LIPOPROTEIN IN HUMANS

The effect of fish oil rich in eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on serum lipoprotein concentrations is not clear, and it is not known whether EPA and DHA are similarly related to serum lipid or lipoprotein levels. We conducted a randomized, 10-week, dietary supplementation trial in which the effects of 6 g per day of 85% EPA and DHA were compared with 6 g per day of corn oil in 156 men and women. Multivariate analyses were used to assess independent relations between plasma phospholipid EPA and DHA and serum lipoprotein levels. In the fish oil group triglycerides fell 21% (p<0.001) and high density lipoprotein cholesterol (HDL-C) rose 3.8% (p<0.05). In the corn oil group triglycerides did not change, but HDL-C rose 6.1% (p<0.01). Compared with fish oil, apolipoprotein A-1 (apo A-I) rose 5.1% after corn oil intake (p<0.05). Plasma EPA and DHA levels rose after fish oil intake and fell after corn oil intake (all p<0.001). The change (DELTA) in EPA was inversely correlated with DELTA-triglycerides (p=0.035) and positively correlated with DELTA-HDL-C and DELTA-apo A-I (both p<0.001) in the multivariate analyses. In contrast, DELTA-DHA was not correlated with DELTA-triglycerides but was inversely correlated with DELTA-HDL-C and DELTA-apo A-1 (both p<0.001). Standardizing for DHA removed the difference in apo A-I levels between groups. This study suggests that EPA and DHA are divergently associated with HDL, possibly through different mechanisms.