Less heart disease, more breast cancer: 5 takeaways from a new report on moderate drinking
A new report on the health effects of moderate drinking paints a mixed picture, with both positive and negative health effects — plus plenty of unknowns.
The studies included in the report, which will help shape the 2025 edition of the Dietary Guidelines for Americans, defined moderate alcohol consumption as no more than one drink per day for women and two per day for men. (A standard drink is 12 ounces of beer containing 5% alcohol, 5 ounces of wine, or 1½ ounces of hard liquor.)
All the studies in the report come with some uncertainty: Scientists can’t randomize one group to drink alcohol and another to abstain for years or decades, and people don’t always keep track of how much they drink, said Dr. Ned Calonge, chair of the committee that compiled it and the associate dean for public health practice at the Colorado School of Public Health.
While the research did show lower death rates among moderate drinkers, the committee couldn’t rule out that they were healthier for some other reason, Calonge said.
“I do think that it would be wrong to recommend that someone start drinking for health reasons,” he said. “If a person chooses to drink, they should drink moderately.”
Here are five takeaways from the report:
Heavy drinking is unhealthy
Men who have more than two drinks per day and women who have more than one have a higher risk of heart attacks, strokes and “all-cause mortality” — essentially, all causes lumped together and adjusted for age. (While everyone will die of something, excessive drinking increases the odds it will happen prematurely.)
“Any potential decreased health risks (from moderate drinking) are wiped out if a person drinks heavily,” Calonge said.
Moderate drinking might have some benefits…
Both men and women who drank moderately had a lower risk of all-cause mortality than those who never drank. They also had a lower risk of dying from cardiovascular disease.
Moderate drinking raises “good” cholesterol, which could explain why people who have one or two drinks a day might be less likely to develop heart disease, Calonge said.
…but not when it comes to cancer
Women who drank moderately had a higher risk of breast cancer than those who didn’t drink at all, and the risk was higher for those who averaged one drink a day than those who drank less frequently.
Alcohol breaks down into substances that can damage DNA when the body metabolizes it, which could explain an increased risk of cancer, Calonge said. The committee couldn’t determine if moderate drinking changes the odds of developing other cancers, he said.
Evidence is still lacking in some areas
One of the committee’s assignments was to determine whether someone’s decision to drink had any effect on their weight and body composition. It couldn’t reach any conclusions, because the underlying studies didn’t account for other differences between people who drink and those who don’t. (For example, maybe the drinkers were more likely to smoke, or a significant number of nondrinkers had a soda habit.)
Controversy isn’t over
A different report, compiled in 2020, came to the opposite conclusion on cardiovascular disease, finding no advantage to moderate drinking. It suggested that men also limit themselves to one drink per day, to minimize their risk of cancer.
Critics of the current report told The New York Times they believed the committee cherry-picked studies that would support benefits from moderate drinking.
The number of studies was small because the committee’s task was to look at evidence since 2010 that compared moderate drinkers to lifelong abstainers, Calonge said. (Comparing current drinkers to people who gave it up for health reasons can make the drinking group look better.)
They used those criteria to exclude studies without knowing which way their results would point, he said.
Ultimately, the field needs more and higher-quality research on moderate drinking, Calonge said.
“I totally reject that (cherry-picking) criticism,” he said. “What I can say is it’s a small snapshot.”