Is it healthier to have a glass of red wine with dinner than to abstain? It's a common belief, but one without a strong scientific basis, according to a new analysis.
Researchers at the University of Victoria pooled the results of 107 studies involving more than 4.8 million participants and determined that, compared to lifetime nondrinkers, people who drink moderately — less than 25 grams of alcohol, or fewer than two drinks, per day — did not have a lower mortality risk.
Tim Stockwell, a co-author of the analysis and researcher at the University of Victoria, said "the evidence for health benefits has become increasingly weak" when it comes to small amounts of drinking.
"We just need to be very skeptical of scientific evidence or scientific studies suggesting there are health benefits," Stockwell added.
Dr. Noelle LoConte, an oncologist at the University of Wisconsin-Madison who wasn’t involved in the research, said she often sees patients who believe a drink or two could be good for them.
"The number one thing I get for pushback is, 'Well, maybe a little bit of wine helps with your heart disease risk,'" she said. But from her perspective, LoConte added, Stockwell's analysis "helps us clearly define that there is probably not a health benefit to alcohol."
However, the new analysis did find an increased risk of death among people who drank 45 or more grams of alcohol per day — about three or more drinks.
The results also suggest that risks associated with drinking depend on a person's sex. Women who had two or more drinks per day were shown to have an increased mortality risk compared to women who had never drank. Meanwhile, men who had three or more drinks per day saw an elevated risk compared to male lifetime nondrinkers.
"The most likely, obvious explanation is that women’s bodies process alcohol differently. Their livers are smaller, on average," Stockwell said. "Another factor, though, is that men, on average, drink more than women and because they have more tolerance to it and are metabolizing it more efficiently, that can also give the appearance of relatively less harm per unit of alcohol."
The glass-of-wine notion didn't appear out of thin air. Some previous studies have suggested that people who drink moderately are less likely to die from heart disease or other causes than people who abstain from alcohol or drink heavily.
Emmanuela Gakidou, a professor of health metrics sciences at the University of Washington’s Institute for Health Metrics and Evaluation, said her own research has shown that small amounts of alcohol are associated with a lower risk of ischemic heart disease and stroke.
Stockwell’s analysis, Gakidou said, "definitely is not showing that small amounts of drinking are harmful."
One reason for the discrepancy between the new analysis and past research is that Stockwell and his team excluded people who had quit drinking. Given that it's fairly common to stop drinking due to health problems or the use of certain medications, incorporating such individuals into a study could skew results and give the impression that abstaining from alcohol makes people less healthy.
"They make the people who continue to drink look healthy by comparison," Stockwell said.
Researchers who study the health effects of alcohol agree on at least a couple things. For one, binge drinking — defined as having five or more drinks on one occasion for men or at least four for women — is not healthy. Second, experts generally agree that it's difficult to make public health recommendations about alcohol limits based on the current evidence.
The World Health Organization declared last year that no amount of alcohol is safe for one’s health. However, the Centers for Disease Control and Prevention recommends that, if people choose to drink, men consume two drinks or less per day and women have one daily drink or less. The CDC defines a drink as a 12-ounce beer, 5-ounce glass of wine or 1.5 ounces of a distilled spirit like gin or vodka.
But both Stockwell and LoConte said that when it comes to cancer, any alcohol intake could raise your risk.
"Alcohol has been a level-one carcinogen for as long as we’ve been listing carcinogens," LoConte said. "It’s on par with things like smoking, UV light, hepatitis B and human papillomavirus or HPV."
LoConte added that she is concerned by the recent rise in alcohol intake among women in the U.S. The number of women who report having heavy drinking days — defined as consuming four or more drinks within a couple of hours — rose 41% from 2019 to 2020, according to a survey from the RAND Corporation, a nonprofit think tank.
"Alcohol use is just skyrocketing after the pandemic, especially in women," LoConte said. "We’re doing more liver transplants for alcoholic hepatitis, which is acute alcohol poisoning to the liver, than we’ve ever done."
But Gakidou said that as a general principle, people who drink in moderation shouldn't worry too much about health concerns.
"If you drink responsibly, and you drink a small amount, I don’t think people will have to feel guilty about it," she said.