Multifaceted dietary exposures and atrial fibrillation: Bidirectional causal evidence from two-sample Mendelian randomization study

Observational evidence has suggested a link between specific dietary intake and the risk of atrial fibrillation (AF). However, the causal effect and direction between them were still inconclusive. We sought to explore the causal relationship by using two-sample Mendelian randomization (MR). We obtained genome-wide association studies on dietary intake from the UK Biobank. Genome-wide association studies of AF in this study were extracted from the FinnGen consortium. MR estimates were calculated using the inverse-variance weighted method as the main method for analysis. Besides, a series of repeated analyses and sensitivity analyses were performed to assess the robustness of the results. Genetically predicted more pork intake was causally associated with higher risk of AF (odds ratio [OR], 7.185; 95% confidence interval [CI], 1.979-26.086; P = .002). Higher salt added to food increased AF risk (OR, 1.465; 95% CI, 1.099-1.9526; P = .009). More dried fruit intake was significantly associated with slower progression to AF (OR, 0.501; 95% CI, 0.291-0.864; P = .012). There is no convincing evidence for the associations between other dietary intake we studied and the risk of AF. In reverse MR analysis, no evidence was showed that AF could influence the dietary factors in all methods. In this two sample MR analysis, we observed that more pork intake and salt added to food may increase the risk of developing AF. Higher dried fruit intake may be protective against AF. Further investigation of the causal relationships is needed to support our novel findings.