Alcohol Consumption and the Risk of Atrial Fibrillation

December 3, 2008 8:21 AM CT

A new study published in the December 3 issue of JAMA found that healthy middle-aged women may have up to two drinks a day without increasing the risk of atrial fibrillation, but three or more drinks increases the risk.

Previous studies in men had suggested that atrial fibrillation risk is increased in men with higher alcohol intakes, but the same correlation was not found in women.

This new study, by researchers from Brigham and Women’s Hospital, Harvard Medical School, and University Hospital in Basel, Switzerland, analyzed data from the Women’s Health Study on nearly 35,000 women age 45 and over. The researchers found that women consuming up to two drinks per day had little risk of atrial fibrillation, but that risk increased significantly at about three drinks per day.

By comparison, a Danish study had found an elevated incidence of afib in men only at the highest risk category, which was five or more drinks per day. 

Read more: Alcohol Consumption and Risk of Incident Atrial Fibrillation in Women

Comments from

Is consuming alcohol OK or not?

Medical and health literature commonly indicates that alcohol consumption is a risk factor for afib. But research also has shown that moderate alcohol intake, defined as 1 drink per day for women and 2–3 drinks per day for men, is heart healthy, though higher consumption can lead to heart attacks and other health issues. So what are we to believe?

As mentioned, previous studies had shown that heavy alcohol consumption was a risk factor for men, but not for women due to the small numbers of them among the heavy drinkers. And no correlation was found in previous studies with the elderly. This study sought to clarify the risk for women age 45 and older.

With small risk of afib in the general population of women consuming 1-2 drinks per day, and a significant rise in the risk for those consuming 3 or more drinks per day, this study confirms that heavy alcohol consumption is a risk factor for middle-aged women as well as men. This finding may not apply to African American women, or women with heart disease, as there were few in the study.

However, these thresholds for afib may still be too high for our general and heart health. Thus the heart-health guidelines, based on research indicating that heart disease risk rises at more than 1 drink for women and more than 2–3 drinks for men, are probably better guidelines for us.

Since heart disease and afib are frequently related, if you have a family history of heart disease or afib it’s probably prudent to follow the more stringent heart-health guidelines above.

Of course, once you have afib, all bets are off. Afib is unique for each of us. For some, alcohol is an afib trigger, and for others it is not.

A couple of comments about the study: The presence of irregular heartbeats was self-reported and might have missed some with asymptomatic (symptomless) afib. However, since most study participants were health care professionals, under-detection of afib was less likely. Also, we don’t know from this study the impact of other lifestyle factors on these findings.