Associations of very high intakes of eicosapentaenoic and docosahexaenoic acids with biomarkers of chronic disease risk among Yup’ik Eskimos

Abstract

Few studies have examined the associations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with biomarkers of chronic disease risk in populations with high intakes. We examined the associations of red blood cell (RBC) EPA and DHA, as percentages of total fatty acids, with biomarkers of chronic disease risk across a wide range of EPA and DHA intakes. In a cross-sectional study of 357 Yup'ik Eskimos, generalized additive models were used to plot covariate-adjusted associations of EPA and DHA with chronic disease biomarkers. Linear regression models were used to test for the statistical significance of these associations. Means (5th-95th percentiles) for RBC EPA and DHA were 2.8% (0.5-5.9%) and 6.8% (3.3-9.0%), respectively. Associations of EPA and DHA were inverse and linear for triglycerides (beta +/- SE = -0.10 +/- 0.01 and -0.05 +/- 0.01, respectively) and positive and linear for HDL cholesterol (beta +/- SE = 2.0 +/- 0.5 and 0.9 +/- 0.6, respectively) and apolipoprotein A-I (beta +/- SE = 2.6 +/- 0.8 and 1.7 +/- 0.8, respectively). Positive linear associations of DHA with LDL and total cholesterol (beta +/- SE = 7.5 +/- 1.4 and 6.80 +/- 1.57, respectively) were observed; for EPA, these associations were nonlinear and restricted to concentrations approximately <5% of total fatty acids. Associations of EPA and DHA with C-reactive protein were inverse and nonlinear: for EPA, the association appeared stronger at concentrations approximately >3% of total fatty acids; for DHA, it was observed only at concentrations approximately >7% of total fatty acids. Increasing EPA and DHA intakes to amounts well above those consumed by the general US population may have strong beneficial effects on chronic disease risk.