Drinking 1 Small Alcoholic Drink a Day May Up Risk 0f Atrial Fibrillation by Hannah Joy on January 13, 2021 at 4:21 PM The study, published in the European Heart Journal, found that, compared to drinking no alcohol at all, just one alcoholic drink a day was linked to a 16% increased risk of atrial fibrillation over an average (median) follow-up time of nearly 14 years. This means that while four teetotallers in 100 might develop atrial fibrillation over the period of the study, five per 100 might develop the condition if they consumed alcohol starting with slightly more than an alcoholic drink a week and more than 75% of them consumed up to one drink a day. The researchers categorized one alcoholic drink as containing 12 g of ethanol, which is the equivalent of a small (120 ml) glass of wine, a small beer (330 ml) or 40 ml of spirits.