Study Links Two Daily Drinks to 1-in-25 Mortality Risk

At low intake, alcohol may be associated with a lower risk of ischemic heart disease, meaning damage to the heart muscle caused by reduced blood flow, and stroke, an injury to the brain caused by interrupted blood supply. When the analysis included cancer and other long-term conditions, however, those possible cardiovascular advantages were outweighed even at seven drinks per week.

How did researchers estimate the risk?

Lead study author Kevin Shield, Ph.D., and colleagues in the United States and Canada first reviewed more than 7,200 scientific publications on illnesses and injuries associated with alcohol. The team used the evidence to estimate risk for each condition and combined those estimates with large national health data sets.

Shield is an associate professor at the University of Toronto and a senior scientist who leads the World Health Organization and Pan American Health Organization Collaborating Centre in Addiction and Mental Health.

Statistical models, meaning mathematical calculations that combine the evidence with those data sets, then estimated how different drinking levels affected the likelihood of serious illness or premature death over a lifetime.

The resulting estimates provide quantitative thresholds missing from the U.S. Dietary Guidelines for Americans, 2025-2030. The guidelines tell Americans to limit alcoholic beverages but identify no numerical threshold. Earlier versions advised men to drink no more than two alcoholic beverages per day and women no more than one.

Naimi said the guidelines carry a useful message that less is best but lack a quantitative framework. The study sought to provide one across the drinking spectrum. Shield said a clearer threshold can help people identify drinking levels associated with increased risk and make more informed decisions.

Why can individual risks differ?

The estimates describe risks across populations rather than predicting precisely what will happen to a particular person. Shield said the calculations relied on the best available data, but lifestyle, genetics, drinking patterns and other personal choices can substantially alter an individual’s outcome.

The team combined risks for conditions already known to be caused by alcohol. Other possible consequences remain under investigation, including emerging evidence linking alcohol consumption to pancreatic cancer. Shield said researchers still need to clarify those relationships and how much alcohol contributes to the risk.

How could the findings change federal guidance?

The central finding is that modeled mortality risk rises with consumption and that low intake produced no significant overall protective effect. The analysis gives public-health agencies a numerical basis for explaining that relationship.

In an accompanying editorial, Robert M. Vincent, a former associate administrator for the U.S. Substance Abuse and Mental Health Services Administration, questioned how the research entered the federal recommendation process. Vincent wrote: “The Alcohol Intake and Health report was explicitly invited to inform alcohol guidance during development of the Dietary Guidelines for Americans, 2025-2030,” and “Despite the study’s adherence to its mandate, its findings were sidelined.”

The paper appeared as volume 87, issue 4, page 621, with DOI 10.15288/jsad.25-00435. Its title, “Alcohol Intake and Health Study: No Protective Effect at Low Levels, With Mortality Increasing to 1 in 25 at 14 Drinks Per Week,” states the central conclusion while leaving individual outcomes dependent on personal circumstances.

The study gives readers a modeled reference point rather than a safety guarantee: above one drink daily, estimated harms become more pronounced, and lower consumption generally means less exposure to alcohol-related disease and death.