One daily drink no longer looks harmless, as alcohol’s risks rewrite moderate drinking rules

Even what many Americans consider moderate drinking is linked to an increased risk of death, disability, and chronic diseases such as cancer and heart disease, according to a new study in the Journal of Studies on Alcohol and Drugs, published at Rutgers University.

Study quantifies risk at common drinking levels

The new research, called the Alcohol Intake and Health Study—initially commissioned by the U.S. federal government to inform development of the new U.S. Dietary Guidelines—found a mortality risk from alcohol of 1 in 25 for people who consumed an average of 14 drinks per week. In contrast, drinking up to seven drinks per week was associated with only minimally elevated risks for most conditions.

“Even low levels of alcohol use come with health risks,” says lead study author Kevin Shield, Ph.D., an associate professor at the University of Toronto and a senior scientist who leads the World Health Organization (WHO)/Pan American Health Organization (PAHO) Collaborating Center in Addiction and Mental Health. “And that risk continues to increase the more someone drinks.”

How researchers measured alcohol’s health impact

Shield and co-authors from the United States and Canada aimed to estimate how lifetime drinking habits affect Americans’ risk of illness and death related to alcohol. After medical experts reviewed more than 7,200 scientific articles on alcohol-related diseases and injuries to determine the level of risk for each condition, the researchers applied those risks to large national health data sets. They then used statistical modeling to estimate how different drinking levels influence long-term health outcomes.

The study offers more concrete guidance than the new U.S. Dietary Guidelines, which currently advise Americans to “limit alcoholic beverages” without specifying how much alcohol is safe to drink. Previous guidelines recommended a daily limit of two alcoholic drinks for men and one for women.

“While the new U.S. Dietary Guidelines contain a useful ‘less-is-best’ message, they provide no quantitative framework. Our study was designed to do just that across the drinking spectrum,” says study co-author Timothy Naimi, M.D., M.P.H., director of the University of Victoria’s Canadian Institute for Substance Use Research and an adjunct professor at Boston University.

“It turns out that two drinks per day, which might be considered ‘moderate’ from a social standpoint, is associated with a substantially elevated risk of a premature death caused by alcohol,” explains Naimi.

Challenging myths about alcohol’s benefits

In addition to mortality risk, researchers examined how drinking patterns influence chronic and acute alcohol-related conditions such as cancer (e.g., esophageal, oral, and breast), cardiovascular disease, liver disease, and injury.

The study overturns a common misconception that alcohol can protect health. “We did not observe a significant protective effect of alcohol on health at any level of consumption,” says Shield. “At low levels, alcohol may be associated with a reduced risk of ischemic heart disease and stroke. But when you look across the full range of health outcomes, including cancer and other chronic diseases, those potential benefits are outweighed by the risks even at seven drinks per week.”

Statistical modeling used in the study to determine health risks was based on “the best possible data,” notes Shield. “However, we can’t assume that means one person’s individual health risk is the same as what is reported here—that depends on other factors like lifestyle, genetics, drinking patterns, and other choices that differ person to person.”

Why a clear threshold matters for drinkers

The researchers estimated risk for all health conditions known to be causally related to alcohol and then aggregated these estimates to determine the total health risk. Yet, new research continues to emerge that links alcohol with additional health conditions, such as pancreatic cancer. “Understanding those relationships, and how much alcohol contributes to those risks, is an area that still needs further work,” says Shield.

By finding that alcohol consumption is associated with increased risk above one drink per day for both men and women, the study offers a much-needed benchmark.

Says Shield, “Having a clearer threshold helps people better understand what level of drinking is associated with increased risk and make more informed decisions when drinking.”

Editorial questions how findings were handled

In an accompanying editorial, Robert M. Vincent, a former Associate Administrator for the U.S. Substance Abuse and Mental Health Services Administration, discusses his view of the behind-the-scenes environment in which the study was produced.

“The Alcohol Intake and Health report was explicitly invited to inform alcohol guidance during development of the Dietary Guidelines for Americans, 2025–2030,” he writes. “Despite the study’s adherence to its mandate, its findings were sidelined.”

Who’s behind this story?

Lisa Lock

BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021.

Full profile →

Advertisements

Robert Egan

Bachelor’s in mathematical biology, Master’s in creative writing. Well-traveled with unique perspectives on science and language.

Full profile →