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.