A report that is intended to shape the next edition of the U.S. Dietary Guidelines has broken sharply with an emerging scientific consensus that alcohol has no health benefits.
The evidence review, by the National Academies of Sciences, Engineering, and Medicine in December, revived a once-dominant hypothesis that moderate drinking is linked to fewer heart attack and stroke deaths, and fewer deaths overall, compared with never drinking.
Many scientists now take issue with that view. And some fear that, based on the new analysis, the influential dietary guidelines may fail to address recent research into the harms of drinking.
The guidelines are revised once every five years, and there have been growing concerns about rising alcohol consumption in the United States in recent decades.
“This report is a thinly veiled effort to undo the growing evidence that alcohol causes cancer and is increasingly associated with serious health outcomes,” said Diane Riibe, who co-founded the U.S. Alcohol Policy Alliance, a nonprofit focused on the harms of alcohol.
The report did note a small but significantly heightened risk of breast cancer associated with moderate drinking, but said there wasn’t enough evidence to link moderate consumption to other cancers. The National Cancer Institute, among other scientific bodies, disagrees.
Alcohol producers “needed the informed national conversation to come to a screeching halt, because none of the current or emerging science says that moderate drinking may be healthier than not drinking,” Ms. Riibe said.
A spokeswoman for the Distilled Spirits Council of the United States, Melissa San Miguel, declined to respond to that criticism.
In a statement co-signed by the council, the Beer Institute, National Beer Wholesalers Association, Wine Institute and Wine & Spirits Wholesalers of America, she said that the dietary guidelines for Americans regarding alcohol “must be guided by a preponderance of the sound science.”
“We urge the secretaries of agriculture and health & human services to uphold the integrity of the dietary guidelines to promote informed and responsible decision-making around alcohol.”
The National Academies report is one of two that will be used to shape the upcoming U.S. dietary recommendations. Another analysis, expected next month, is being prepared under the auspices of a governmental committee called the Interagency Coordinating Committee on the Prevention of Underage Drinking.
The process of commissioning two separate reports on moderate drinking is entirely new. In the past, the U.S. Dietary Guidelines Advisory Committee evaluated the scientific evidence about alcohol, along with other components of the diet, and made recommendations.
That heavy drinking is harmful has never really been in question. But the 2020 scientific report, prepared the last time the dietary guidelines were updated, also noted that alcohol is a carcinogen and generally unhealthy.
Scientific advisers even floated the idea of “tightening guidelines” for men, saying that capping the recommendation for men at one standard drink or 14 grams of alcohol a day “should be strongly considered.”
This suggestion upset the alcohol industry, said Dr. Marion Nestle, a nutritionist and public health advocate who has served on the U.S. Dietary Guidelines Advisory Committee and has written about the food industry’s influence on the process.
“One drink a day for men — holy smokes!” she said, paraphrasing the reaction. “What’s going to happen to all those people who go to bars? Could warning labels be next?”
The final 2020 dietary guidelines did acknowledge that “emerging evidence suggests that even drinking within the recommended limits may increase the overall risk of death from various causes, such as from several types of cancer and some forms of cardiovascular disease.”
Still, the guidelines kept to the advice that moderate consumption of up to two daily drinks for men and one for women is safe.
“They ended up saying the same thing as always,” Dr. Nestle said, but added: “The industry was scared.”
Rethinking Drinking
Health authorities all over the world have been encouraging people to drink less, quit drinking altogether or aim for two to three alcohol-free days each week.
In recent years, the World Health Organization, Canadian health authorities, the United Kingdom and several other countries have all signed on to the idea that there’s no safe level of drinking. Lately some scientists have ventured the opinion that the risks could start with the first drop.
But the official advice in the United States has not much changed, despite the conclusion of the 2020 scientific report that the risks associated with low consumption may have been underestimated.
In late 2022, as preparations were underway to revise the dietary guidelines, Congress gave $1.3 million to the National Academies to assemble a nongovernmental panel to examine the research on moderate drinking.
Critics saw in the move an effort to placate the alcohol industry with a report more likely to support moderate drinking. Two Harvard researchers whose research had supported moderate consumption were quickly named as possible panel members.
The National Academies removed them from consideration after an outcry from outside experts and advocates. But they were replaced by two other Harvard scientists whose research has also been supportive of a link between moderate drinking and a reduced risk of cardiovascular disease.
Of the four, at least three received funding from the alcohol industry at some point in their careers.
After a year of study, the National Academies panel found that there was sufficient evidence to draw only three conclusions with some certainty.
They were that a pattern of moderate drinking was associated with 18 percent fewer cardiovascular disease deaths, with a 16 percent lower risk of all-cause mortality, and with a 10 percent heightened risk of breast cancer for women.
“All of this is based on observational studies,” which can turn up correlations between moderate drinking and health outcomes but do not demonstrate a cause-and-effect relationship, said Dr. Bruce N. Calonge, an epidemiologist at University of Colorado Denver, who chaired the National Academies panel.
“The evidence base from which to draw conclusions about alcohol and health is imperfect.”
Big alcohol manufacturers have said little about the National Academies report, but smaller vintners and craft beer makers cheered.
“This affirms what I have been saying all along,” Laura Catena, a vintner in California, said. “There are salutary cardiovascular effects from moderate alcohol consumption.”
Marty Jones, a craft beer promoter in Denver, called the report “good news for common sense and the beer trade.”
Scientists who are skeptical about alcohol’s health benefits said they had anticipated the conclusions. Dr. Tim Stockwell, former director of the Canadian Institute for Substance Use Research and a professor at the University of Victoria, said the panel used very restrictive criteria in selecting studies for review.
As a result, many studies of alcohol’s harms were excluded.
For example, he said, “there are hundreds of studies finding increased risks of cancers at low levels of drinking. They’re saying there’s no evidence, but they excluded the relevant evidence.”
The National Cancer Institute links even moderate drinking to colorectal cancer, at least one type of esophageal cancer, and cancers of the head and neck, as well breast cancer.
For cardiovascular deaths, the National Academies panel included only four papers in a meta-analysis, including one by Harvard researchers that linked moderate drinking to a lower risk of sudden cardiac death in women.
That research was observational, like all of the studies that were examined. There are few randomized controlled trials of moderate drinking, so it is difficult to know why moderate drinkers might have fewer heart attacks and strokes.
Their better cardiovascular health may not be a result of the alcohol they consume, but of a slew of other characteristics, experts say.
People who drink in moderation may be moderate in other ways, eating well and engaging in other healthy behaviors, and they tend to be more educated and have socioeconomic advantages — all factors associated with good overall health.
When studies are published showing harms associated with alcohol, the industry frequently replies by pointing to the official recommendations condoning up to two drinks a day for men and one for women.
In September, for example, in response to an American Association for Cancer Research report that attributed one in 20 cancers to alcohol, Dr. Amanda Berger, senior vice president of science and research for the Distilled Spirits Council, said: “We urge adults who choose to consume alcohol to follow the Dietary Guidelines for Americans.”
But the evidence against alcohol has been evolving for years now. Scientists recognize that their advice may not be heeded. Drinking is a popular pastime, though 45 percent of Americans have come to believe that even one or two drinks a day is bad for their health, according to a Gallup poll in July.
The government’s upcoming report, the next shoe to drop in this controversy, is expected to focus on health outcomes known to be caused by alcohol, not merely associated with it.
And that may set the stage for dietary guidelines that say something truly new: Drink less.
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