The findings from researchers at the University of California go against the common belief that moderate drinking can be good for the heart.
Study author Dr. Gregory Marcus said: ‘Our study provides the first human evidence of why daily, long-term alcohol consumption may lead to the development of this very common heart rhythm disturbance.
‘We were somewhat surprised that a relatively small amount of alcohol was associated with a larger left atrium and subsequent atrial fibrillation.
Researchers analyzed figures from 5,220 adults from an ongoing project.
The participants, who had an average age of 56, underwent electrocardiograms to measure activity of the heart. Of 17,659 scans taken over 6 years, researchers detected 1,088 cases of atrial fibrillation.
They found drinking just 10g of alcohol had a 5% higher chance of developing atrial fibrillation.
Researchers said the link remained even after high blood pressure, diabetes, or smoking were taken into account.
Doug Aylard the owner of Vino Garage in Columbia, which sells wine says he’s heard for decades about the health benefits of alcohol in moderation, especially red wine. “Apart from the whole relaxing quality of it, the alcohol tends to help thin the blood to help the heart more,” he says.
Of the new study that counters the earlier ones, Aylard says, “It really doesn’t worry me. I think it’s too small of a study. Looking at it they really didn’t take other conditions into consideration, such as diet.”
Even the lead author of the study, Dr. Gregory Marcus, says the study cannot say that the alcohol use is the cause of the atrial fibrillation.
He says some people may have a genetic predisposition to it and he would recommend that they avoid alcohol, while others may benefit from moderate alcohol use. The American Heart Association defines moderate use as one or two drinks a day for a man and one drink per day for a woman.