The current study was led by Dr. Renate Schnabel, a cardiologist at the University Heart and Vascular Center, in Hamburg, Germany. It included 100,092 adults who were initially free of a-fib and followed for about 14 years. During that time, more than 5,800 developed the condition.
In general, people’s self-reported drinking habits correlated with the odds of a-fib — even after the researchers accounted for factors such as high blood pressure, obesity, smoking and diabetes.
“This doesn’t prove causality, but it’s definitely a finding to take note of,” said Dr. John Osborne, a Dallas-based cardiologist and volunteer expert with the American Heart Association.
According to Osborne, there are biological reasons that alcohol could have opposite effects on the risks of heart attack and a-fib.
Heart attacks are typically caused by artery blockages, whereas a-fib arises from a problem in the heart’s electrical system. Alcohol can activate the sympathetic nervous system and the “fight-or-flight” response, which, among other things, accelerates heart rate, Osborne said.
There’s also evidence, he said, that alcohol can make cells in the atria “electrically unstable.”
One possibility is that in some people with asymptomatic, or “silent,” a-fib, drinking could exacerbate the situation, Osborne added.
Like Conen, he said that people with known a-fib may want to reconsider those glasses of wine, even if they drink in moderation.
For those without a-fib, the question is trickier. A-fib is complicated and there are numerous risk factors, Osborne noted, from thyroid disease and high blood pressure to obesity and family history.
But, he said, “I think that over the past 20 years, we’ve been moving away from the idea that a drink or two a day is ‘great’ for your heart. Now we’re rethinking that.”
More information
The American Heart Association has more on atrial fibrillation.