One drink a day can indeed lower the risk of cardiovascular disease due to the prevalence of antioxidants, but it can also cause an irregular heartbeat, according to a study led by Dr. Peter Kistler of the Baker IDI Heart and Diabetes Institute and the Alfred Hospital in Melbourne, Australia.
"Alcohol is not universally 'good' for the heart," Kistler told Reuters. "It is beneficial for the 'plumbing' or blood supply to the heart muscle, but for the 'electrical' part of the heart or the heartbeat it is not."
Of the 900,000 people tested in the study, nearly eight percent who drank a beer or glass of wine daily experienced increased instances of atrial fibrillation, a kind of irregular heartbeat (arrhythmia). This condition can lead to blood clots and strokes if untreated.