Keep tabs on your drinking
When it comes to alcohol, moderation is still the mantra. But even one drink a day may pose a risk to the heart.
Wine, champagne, and cocktails are standard fare at many holiday gatherings. But before you raise your glass, make sure you’re aware of just how much alcohol you’re actually consuming—and how it may affect your heart.
As part of a standard health history, most physicians will ask about your drinking habits. In general, moderate drinking—defined as one drink per day for women and two drinks per day for men—is considered safe. But there are some caveats.
Defining “one” drink
“We ask people about numbers of drinks, but you have to be careful about what they mean by that,” explains cardiologist Dr. Stephen Wiviott, associate professor of medicine at Harvard Medical School. For some people, “one drink” may be 6 ounces of whiskey, which is actually four drinks, he notes. Wine drinkers may not realize that wine’s alcohol content can range from 7% to 16% and that a single serving of wine is only 4 to 5 ounces, or about ½ cup (see “What’s a standard drink?”).
“People who’ve had a heart attack will ask me if it’s okay to have a drink now and then,” says Dr. Wiviott. If they’ve fully recovered and are generally healthy, he tells them that research suggests that people who drink moderate amounts of alcohol are at no greater risk of heart disease than people who don’t drink at all.
Examining the evidence
But despite popular belief, the evidence that alcohol is good for your heart is fairly weak and based solely on what researchers call observational data. “We observe that people who drink moderately have lower rates of heart disease and death from heart disease, but that doesn’t prove cause and effect,” says Dr. Wiviott.
For example, light-to-moderate drinkers tend to be educated and relatively wealthy, and they’re likely to have heart-healthy habits that may explain their lower risk. And people who are ill or taking certain medications often are told by their doctors to avoid alcohol. So, when researchers compare drinkers and nondrinkers, the drinkers have fewer health problems and live longer—but that might not be a reflection of the drinking.
There’s a well-established connection between binge drinking and atrial fibrillation or afib, an irregular heart rhythm that can increase the risk of a stroke. It’s known as holiday heart syndrome because it typically happens around the holidays and on weekends, when some people drink to excess. It’s not exactly clear why binge drinking—defined as consuming about four to five drinks over a two-hour period—triggers afib. But it can happen in people with and without a history of the heart rhythm problem.
A recent study—also observational—found that even as little as one drink a day may enlarge the heart’s upper left chamber (atrium) and increase the risk of developing afib. The findings, published in the Sept. 14, 2016, Journal of the American Heart Association, were based on 5,220 people from the long-running Framingham Heart Study. Researchers found that every 10 grams of alcohol (the amount in one drink) consumed was linked to a 5% higher risk of developing afib. About 24% (and in some cases, up to 75%) of the higher risk could be traced back to an enlargement of the left atrium. Stretching of the atria—which can also result from longstanding high blood pressure or a genetic problem—seems to make the heart more electrically unstable, Dr. Wiviott explains.
An afib association
This isn’t the first study to examine long-term moderate drinking and afib, and some of the earlier studies didn’t show a link. But several factors make the current results especially compelling, says Dr. Wiviott. “There seems to be a dose-related response; that is, a little alcohol increases the risk a small amount, and the more you drink, the higher the risk,” he says. Dose-related effects can support a true association, especially when they’re coupled with a finding that explains the possible mechanism (in this case, an enlarged atrium).
These new findings don’t change the observation linking moderate drinking to a lower risk of heart attack noted in some studies. But no one should ever start drinking in hopes of avoiding a heart attack, he says. For his patients who do drink alcohol, he suggests no more than one drink a day, even for men. If you have afib and drink alcohol, you should probably have a discussion with your doctor, Dr. Wiviott advises.
Setting limits, drinking less
The National Institute on Alcohol Abuse and Alcoholism already advises people ages 65 and older to limit themselves to one daily drink. Age-related changes, including a diminished ability to metabolize alcohol, make higher amounts risky regardless of gender. People who are under 21, pregnant women, and those with a personal or family history of alcohol misuse should avoid alcohol altogether.
If you’re trying to cut back on your drinking, try these tips:
- Keep a drinking diary. Write down what and how much you drink for several weeks to get a sense of how much you usually imbibe.
- Keep alcohol out of your house. This can help you to limit your drinking to restaurants and social occasions.
- Dilute and drink slowly. Dilute your wine or cocktail with sparkling water and ice. Sip it slowly. Never drink on an empty stomach.
- Establish alcohol-free days. Choose a few days per week to abstain completely from alcohol.
Originally published on Harvard University.