For years, many people have believed that enjoying a glass of wine with dinner or sharing a couple of drinks with friends carried little health risk. A major new study now challenges that assumption, finding that even what many Americans consider moderate drinking is linked to a higher risk of cancer, chronic diseases, disability, and premature death.

The research, published in the Journal of Studies on Alcohol and Drugs, offers one of the most comprehensive assessments yet of how alcohol affects long-term health. Scientists from the United States and Canada examined evidence from more than 7,200 scientific studies and applied those findings to national health datasets to estimate the lifetime risks associated with different levels of alcohol consumption.

“This study provides the most comprehensive US estimates to date of lifetime risks of alcohol-attributable mortality and morbidity, showing that even moderate levels of consumption increase the risk of premature death and disability,” said study co-author Katherine M. Keyes, professor of epidemiology at Columbia University Mailman School of Public Health. “No protective effect of drinking was observed even at low levels.”

Lead author Kevin Shield, associate professor at the University of Toronto and senior scientist leading the WHO/PAHO Collaborating Centre in Addiction and Mental Health, said the findings challenge long-held beliefs about alcohol and health. “Even low levels of alcohol use come with health risks,” he said. “And that risk continues to increase the more someone drinks.”

Researchers found that consuming two alcoholic drinks per day—a level often regarded as "socially moderate"—was associated with a substantially higher risk of alcohol-related premature death. The risks extended beyond mortality and included a broad range of illnesses, such as liver disease, cardiovascular disease, and several forms of cancer, including breast, mouth, and oesophagus cancers.

The findings align with growing international evidence linking alcohol to cancer. The World Health Organization has repeatedly stated that no amount of alcohol can be considered completely safe when it comes to cancer prevention. Alcohol breaks down in the body into a toxic substance called acetaldehyde, which can damage DNA — the genetic instruction manual inside cells. When DNA damage accumulates over time, the likelihood of cancer increases.

The study also challenges the popular notion that moderate drinking protects the heart. While some studies have shown slight decreases in the risk of conditions like ischaemic heart disease and stroke, the researchers found that these possible benefits were not enough to outweigh the higher risks of cancer and other diseases related to alcohol when looking at overall health.

Recent research published in leading medical journals has similarly questioned earlier claims of cardiovascular benefits from moderate alcohol consumption. Scientists increasingly argue that lifestyle differences between drinkers and non-drinkers, rather than alcohol itself, may have influenced previous findings.

The researchers cautioned that individual risk varies. Genetics, diet, exercise habits, smoking status and drinking patterns can all influence how alcohol affects a person's health. Statistical models provide population-level estimates rather than precise predictions for any one individual.

Even so, the study provides what experts describe as an important benchmark. It gives clearer guidance in an area often muddied by mixed messages, with identified increased health risks above one drink per day for both men and women. And as scientists continue to study links between alcohol and other diseases, including pancreatic cancer, the latest evidence suggests that when it comes to alcohol and long-term health, less truly may mean less risk.