Relationship between fish intake, omega-3 fatty acids, mercury, and risk markers of coronary heart disease (NHANES 1999--2002)

Background. Fish consumption is inversely associated with coronary heart disease (CHD), possibly due to the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Dietary mercury from fish has been hypothesized to increase the risk of CHD.;Objective and design. Test the relationships between fish FFQ/30 days and 24-hour DHA+EPA intakes and CHD risk markers (high density lipoprotein (HDL), low density lipoprotein, total cholesterol, triacylglycerol, and C-reactive protein (CRP)) in F 16-49 y (NHANES 99-02), and if mercury attenuated any cardio-protective benefits.;Results. Fish FFQ was negatively associated with CRP (95% CI: -0.19 to -0.02, P=0.015) and positively associated with HDL (95% CI: 0.31 to 2.5, p=0.014), and was not significantly attenuated after adjustment for multiple other risk factors. Addition of mercury resulted in non-significant relationships between fish FFQ and HDL (95% CI: -0.60 to 1.6, p<0.05). DHA+EPA and other nutrients in fish may be adequate to offset the hypothesized CHD risks of mercury.