In August 2017, researchers from the USA, Denmark and Canada published the results of their study to assess the effect of chocolate on atrial fibrillation or flutter. 55 502 individuals (26,400 men and 29,102 women) aged 50-64 years were included in the study and followed up for an average of 13.5 years. A total of 3,346 cases of atrial fibrillation were diagnosed during this time. Information on chocolate consumption was collected via a food-frequency questionnaire. Results showed that when compared with a chocolate intake of less than once per month, the risk of atrial fibrillation decreased in a dose-response manner for 1-3 servings/month, 1 serving/week and 2-6 servings/week, with similar results for men and women.
Mostofsky E et al. Chocolate intake and risk of clinically apparent atrial fibrillation: the Danish Diet, Cancer, and Health Study. Heart. 2017 Aug;103(15):1163-1167