Evidence of an association between carbohydrate intake and atrial fibrillation (AF) incidence remains limited. We investigated the association between carbohydrate and staple food consumption and AF risk in a Japanese urban population.

Our population-based prospective cohort study included 5229 adult participants (mean age 56.9 years; 46.5% men) who completed a Food Frequency Questionnaire. Multivariable-adjusted Cox regression models were used to assess the association between carbohydrate intake (g/day) and staple food consumption (rice, noodles and bread) and AF incidence after adjusting for confounding factors. During 68 668 person-years of follow-up (mean, 13.1 years), 226 individuals developed AF. Total and simple carbohydrate intakes were associated with an increased AF risk in men (HR and 95% CI for Q4 vs Q1 were 2.51 (1.06 to 5.96) and 3.29 (1.33 to 8.13), respectively). In contrast, there were no significant associations between total carbohydrate, simple or complex carbohydrate intake and AF risk in women (HR and 95% CI for Q4 vs Q1 were 1.33 (0.27 to 6.65), 2.75 (0.74–10.26) and 1.04 (0.38-2.83), respectively). We found no association between staple foods and AF risk in men or women.

Our findings imply that the association between carbohydrate intake and AF risk is influenced by the type of carbohydrates. We found a positive association between high intake of simple carbohydrates and AF risk in men whereas the association was negative for complex carbohydrate intakes. Meanwhile, the results in the women’s group were inconclusive.