It’s called ‘holiday heart’ because it happens to binge drinkers who feel a flutter or irregular heartbeat after too many cocktails at parties. But a research review suggests it can happen after just one drink.

Conventional wisdom, based on plenty of previous research, is that the occasional glass of wine or beer can be good for the heart, reducing the risk of heart disease and stroke as well as death from cardiovascular causes, lead study author Peter Kistler of the Baker IDI Heart and Diabetes Institute and the Alfred Hospital in Melbourne, Australia, said.

For the current study, however, researchers examined data collected on almost 900,000 people and found an eight per cent risk increase for atrial fibrillation with each alcoholic drink consumed per day.

“Alcohol is not universally ‘good’ for the heart,” Kistler said. “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.”

While nobody should binge drink during the holidays, people with a history of atrial fibrillation should be especially vigilant about avoiding or limiting alcohol, Kistler said.

While nobody should binge drink during the holidays, people with a history of atrial fibrillation should be especially vigilant about avoiding or limiting alcohol

The study, published in the Journal of the American College of Cardiology, does not prove that an extra cocktail after dinner directly causes atrial fibrillation, the authors note.

And more research still needs to be done to determine the specific mechanisms behind the relationship between alcohol and atrial fibrillation, the authors note.

The pathophysiological mechanisms responsible for the relationship between alcohol and atrial fibrillation may include direct toxicity and alcohol’s contribution to obesity, sleep-disordered breathing and hypertension, they say.

One challenge with the study and most research on the heart effects of alcohol is that researchers rely on people to accurately recall and report on how much they drink, a flawed process that often leads participants to underestimate their alcohol consumption, noted Tim Stockwell, director of the Centre for Addictions Research and a professor at the University of British Columbia in Vancouver, Canada.

Often, studies that count former drinkers as ‘abstainers’ can obscure the effects of alcohol on the heart, too, making occasional drinkers look healthier than abstainers, Stockwell, who was not involved in the study, said by e-mail.

Even so, there are some common sense steps anyone can take to lower the odds of heart rhythm problems after that next holiday party.

“Certainly drinking with food, interspersing with non-alcoholic drinks and generally keeping the dose of alcohol low are all recommended,” Stockwell said. “This all reduces the heart’s exposure to cardiotoxins.”