A major report on alcohol’s health effects — which will inform the 2025 Dietary Guidelines for Americans — found moderate drinkers had lower all-cause mortality, and a lower risk of death from cardiovascular disease, than those who never drank. The findings are sure to cause a stir, especially once a separate panel of experts releases its own alcohol report in coming weeks.
For years researchers and public health officials have been taking a harder stance on alcohol as evidence has emerged of its associations with various diseases, including certain cancers and liver disease. The head of the National Institute on Alcohol Abuse and Alcoholism, George Koob, has said there are “no health benefits to alcohol.” The new 230-page report, released Tuesday by the National Academies of Sciences, Engineering, and Medicine, seems to contradict those assertions.
The “Review of Evidence on Alcohol and Health” from NASEM does not make recommendations. Instead it summarizes the available evidence published in the past five to 15 years on how alcohol affects lactation, overweight and obesity, cancer, cardiovascular disease, neurocognition and all-cause mortality. Recommendations will be made by the main dietary guidelines committee next year, using NASEM’s review and another, from a separate panel in the Department of Health and Human Services. That report has not been released yet but is expected by next month.
The 14-person NASEM committee combed through the recent science on the connection between moderate drinking and weight, cancer, cardiovascular disease, neurocognition and all-cause mortality — with a focus on studies whose comparison groups didn’t combine never-drinkers with former drinkers, in order to avoid bias. Moderate drinking is defined as two drinks per day for men, or one drink per day for women.
“Research on the health effects of moderate drinking is challenging. Currently there are no published clinical trials for most important health outcomes, so even the substantial evidence base noted above is challenged by threats of bias inherent in observational studies, especially residual confounding,” chair Ned Calonge, associate dean for public health practice and professor of epidemiology at Colorado School of Public Health, wrote in the report’s introduction.
The committee graded the quality of the evidence using a scale of low to high certainty, with low certainty meaning the evidence was not enough, or was too inconsistent, to assess the health effects.
The committee’s conclusions
For all-cause mortality, the panel’s review found strong evidence that heavy drinking has adverse effects on health, including increasing the risk of the leading causes of death. “However, the association of moderate alcohol consumption with all-cause mortality is less clear,” the report says, citing evidence from eight eligible studies. According to its meta-analysis, the committee found those who consumed moderate levels of alcohol had a 16% lower risk of all-cause mortality than those who never drank. This conclusion was graded as being of moderate certainty, meaning there was enough evidence to determine the health effects, but there are limitations due to the quality of the evidence. Future data could change the conclusion.
Meta-analyses the committee reviewed found moderate drinking was associated with a lower risk of heart attack, stroke and cardiovascular disease mortality as compared to never drinking. The conclusions on nonfatal heart attack and stroke were of low certainty, while the conclusion on cardiovascular disease mortality was of moderate certainty.
The committee conducted a systematic review of seven eligible studies on weight changes and alcohol. It determined there was not enough evidence to draw a conclusion on moderate alcohol drinking versus never drinking when it comes to weight-related outcomes. The same went for the association for amounts of moderate alcohol and changes in weight, or changes in waist circumference.
The panel found that within the range of what is considered “moderate” drinking, high versus low consumption had similar associations to body mass index, overweight and/or obesity in men. These were conclusions of low certainty. The data were inconsistent in women.
A review of 14 studies on alcohol and certain cancers led the committee to conclude (with moderate certainty) that consuming a moderate amount of alcohol was associated with a higher risk of breast cancer as compared to never drinking. Among moderate drinkers, those who drank more had a higher risk compared to low-end drinkers. This was a conclusion of low certainty.
The committee did not reach a conclusion on the associations between moderate drinking and risk of colorectal cancer, or oral cavity, pharyngeal, esophageal or laryngeal cancers. A low certainty conclusion found moderate drinkers who drank more had a higher risk of colorectal cancer when compared to moderate drinkers who consumed less alcohol.
The available research was mixed on the link between moderate drinking and the risk of neurocognitive issues, such as dementia, Alzheimer’s and cognitive decline. The committee did not draw any conclusions on neurocognition outcomes. There was not enough evidence to answer questions about lactation, including whether drinking impacts milk production or composition or infant development.
Report will be met by changing attitudes on alcohol
Several of the conclusions are sure to alarm researchers who believe alcohol has no health benefits, and drives many harms.
Watchdogs have criticized the NASEM committee for including researchers with financial ties to the alcohol beverage industry, and too few panelists with relevant research experience. Large alcohol firms also have an acute interest in the dietary guidelines outcome, and how it shapes public perception of drinking. Major alcohol companies have spent millions lobbying lawmakers and other federal officials about the guidelines since 2022.
Meanwhile, alcohol’s toll in the U.S. has only gone up since the last guidelines were drafted. The average number of deaths per year from excessive alcohol use increased 29% between 2017 and 2021. Alcohol consumption and related harms only worsened during the pandemic. Data from the Centers for Disease Control and Prevention says more than 140,000 deaths per year — including 20% of deaths of young people aged 20 to 49 — are due to excessive alcohol use.
Medicine has over time turned in the direction of recommending less drinking, and away from the idea that a glass of wine with dinner is good for health (the “French paradox” popularized in the late 20th century). Other countries have lowered their recommended drinking thresholds. In Canada, researchers recommended public health messaging that emphasized how any level of drinking carried a risk, and it went up in tandem with a person’s consumption. Recent surveys in the U.S. also suggest public attitudes on drinking are shifting.
HHS — potentially run by “Make America Healthy Again” leader Robert F. Kennedy Jr. — will get final say over how the alcohol reports play into the official dietary guidelines. While Kennedy has said he is sober, and has railed against additives and health-harming chemicals in America’s food supply, he hasn’t said much about alcohol regulation.
Drinking recommendations in the U.S. have gone relatively unchanged for decades. Since the 1990s, the guidelines have told the public to drink alcohol “in moderation,” if at all. Women should have no more than one drink per day. A standard drink in the U.S. has about 14 grams of pure alcohol in it, equal to a 12-oz. bottle of 5% ABV beer or a five-ounce glass of 12% ABV wine. Men should have no more than two per day, the guidelines say.
The guidance is for daily consumption, so someone cannot have a week’s worth of drinks in one or two sittings and be compliant. Having four or more drinks in one sitting is considered binge drinking for women; five or more for men. Certain groups, including pregnant people, are advised to avoid drinking altogether. Those who abstain from alcohol should not start drinking.
Recent studies have tied even conservative alcohol use to heightened risk of certain cancers, chronic diseases and injuries. (A 2020 recommendation to lower drinking thresholds for men was rejected by the government.)
Earlier this month, scientists issued their report on the role of food in health promotion and disease prevention. Dietary guidelines are just recommendations, but they influence food assistance programs, policy, school meals, and clinical practice. They also reflect social and scientific changes over time about what Americans ought to eat and drink. Whatever drinking (or abstaining) advice goes into the final guidelines will stand for five years.
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