Compared to people who never drink alcohol, people who drink low or moderate amounts didn't see any reduction in risk of death from any cause, according to a study published in JAMA Network Open, findings that contradict previous studies that suggested moderate drinking could come with some health benefits.

Study details

For the study, researchers looked at data on over 4.8 million people and 425,564 deaths from 107 studies in more than 20 countries published between 1980 and 2021.

The researchers found that, compared to people who never drink alcohol, "low-volume" drinkers — defined as those consuming less than 25 grams of alcohol, or fewer than two drinks per day — did not see any reduction in their risk of death from any cause.

Similarly, "medium-volume" drinkers — defined as those consuming between 25 and 44 grams of alcohol a day — saw no significant protection or harm from their drinking compared to abstainers.

When looking at "high-volume" drinkers — defined as those consuming between 45 and 64 grams of alcohol per day — the researchers found a 19% increased risk of all-cause mortality. Similarly, those who consumed more than around 4.5 drinks per day — or 65 grams of alcohol — had a 35% increased risk of death from any cause compared to abstainers.

The threshold for safe levels of drinking was lower for women than it was for men, the researchers found. Women who consumed around two to three drinks per day saw a 21% increased risk of death compared to abstainers, while high-volume and higher-volume drinkers who were women had a 34% and 61% increased risk of death, respectively.

Reaction

The study's results contradict previous  studies  that found that moderate drinkers are less likely to die from heart disease and other causes than those who abstain from alcohol or those who drink heavily.

In the new study, researchers excluded people who had quit drinking because of health issues, which they argue can bias study results to wrongly suggest that not drinking is less healthy than drinking.

"These abstainers are often older people who gave up alcohol because their health was bad," said Tim Stockwell, lead author on the study and a professor of psychology at the  University of Victoria. "Being able to drink is a sign you are still healthy, not the cause of it. There are lots of ways these studies give false results that are misinterpreted to mean alcohol is good for you."

"The idea that alcohol is beneficial in moderation has a profound influence on global, national, and regional estimates of alcohol's impact on health and safety," Stockwell added. "It also has profound implications for guidelines prepared by health authorities for alcohol drinkers wishing to reduce health risks."

As for why women had a lower threshold for risk related to alcohol consumption than men, Stockwell said the most likely explanation is that women 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."

Timothy Brennan, chief of clinical services for the  Addiction Institute of Mount Sinai, said the study makes it clear "that heavy drinking not only increases the likelihood of developing a variety of diseases, but it also increases the risk of dying."

Brennan recommends that men limit their alcohol consumption to two drinks per day or less, while women limit their consumption to one drink per day or less.

Emmanuela Gakidou, a professor of health metrics sciences at the University of Washington's Institute for Health Metrics and Evaluation, noted that the new study "definitely is not showing that small amounts of drinking are harmful," and that those drinking in moderation shouldn't be concerned about health risks.

"If you drink responsibly, and you drink a small amount, I don't think people will have to feel guilty about it," she said. (Monaco, MedPage Today, 3/31; Bendix, NBC News, 3/31; Cimons, Washington Post, 3/31)