Plant Omega-3 Fatty Acids May Lower Risk of Atrial Fibrillation in Individuals with a Low Intake of Marine Omega-3 Fatty Acids

BACKGROUND: Omega-3 fatty acids derived from seafood acids may influence cardiac arrhythmogenesis, whereas the role of the major plant-derived omega-3 fatty acid, alpha-linolenic acid (ALA), on atrial fibrillation (AF) is largely unknown. OBJECTIVES: We aimed to investigate the association between ALA intake and risk of incident AF overall and in subjects with a low intake of marine omega-3 fatty acids. METHODS: We followed a total of 54,260 middle-aged men and women enrolled into the Danish Diet, Cancer, and Health cohort for development of AF using nationwide registries. Intake of ALA was assessed using a validated food frequency questionnaire and modeled as a restricted cubic spline. Statistical analyses were conducted using Cox proportional hazards regression. RESULTS: We identified a total of 4902 incident AF events during a median of 16.9 y of follow-up. In multivariable analyses, we observed indications of a statistically nonsignificant inverse association between ALA intake and risk of AF up to an ALA intake of 2.5 g/d, whereas no appreciable association was found for higher intakes of ALA. A statistically significant dose-dependent negative association was found between ALA intake and risk of AF in individuals consuming < 250 mg marine omega-3 fatty acids daily, whereas no association was found in those with a higher intake of marine omega-3 fatty acids. CONCLUSIONS: Intake of ALA was associated with a lower risk of AF in individuals consuming a low intake of marine omega-3 fatty acids. This finding is novel and warrants further investigation.