Dietary ω-3 fatty acids and the incidence of atrial fibrillation in the Million Veteran Program.

BACKGROUND

Although recent large randomized clinical trials have reported an increased risk of atrial fibrillation (AF) with marine ω-3 fatty acid supplements, it is unclear whether dietary marine ω-3 fatty acids assessed through food frequency questionnaires are associated with AF risk.

OBJECTIVES

We sought to test the hypothesis that dietary eicosapentaenoic acid/docosahexaenoic acid/docosapentaecnoic acid (EPA/DHA/DPA) is associated with a higher risk of AF in a large prospective cohort of US Veterans.

METHODS

We analyzed data from Million Veteran Program participants who completed self-reported food frequency questionnaires. We used multivariable Cox regression to estimate the HRs of AF across quintiles of ω-3 fatty acid consumption and a cubic spline analysis to assess the dose-response relations between ω-3 fatty acids and AF.

RESULTS

Of the 301,294 veterans studied, the median intake of ω-3 fatty acids (EPA/DHA/DPA) was 219 mg/d (IQR: 144-575), and the mean age was 64.9 y (SD: 12.0); 91% were men, and 84% were White. Consumption of EPA/DHA/DPA exhibited a nonlinear inverse relation with incident AF characterized by an initial decline to 11% at 750 mg/d of marine ω-3 fatty acid intake followed by a plateau.

CONCLUSIONS

Contrary to our hypothesis, dietary EPA/DHA/DPA was not associated with a higher risk of AF but was inversely related to AF risk in a nonlinear manner.