For decades, the idea that a glass of wine at dinner or an occasional cocktail with friends might actually be good for your health has persisted, echoed in countless studies and social circles alike. But a sweeping new international study, published on October 15, 2025, in BMJ Evidence-Based Medicine, is challenging that long-held belief—and the findings are causing quite a stir among both scientists and the public.
The study, led by researchers from the University of Oxford, Yale University, and the University of Cambridge, draws from a massive pool of data: observational records from more than half a million participants in the U.S. Million Veteran Program and the UK Biobank, as well as genetic information from over 2.4 million people across 45 studies. According to The Washington Post, the results are clear and sobering: there is no safe level of alcohol consumption when it comes to protecting your brain and preventing dementia.
"Our findings challenge the common belief that low levels of alcohol are beneficial for brain health," said Dr. Anya Topiwala, senior clinical researcher at Oxford Population Health and the study’s lead author, in a release cited by Deseret News. "Genetic evidence offers no support for a protective effect; in fact, it suggests the opposite. Even light or moderate drinking may increase the risk of dementia, indicating that reducing alcohol consumption across the population could play a significant role in dementia prevention."
For years, the prevailing wisdom was that moderate alcohol consumption—think a glass of red wine a day—might actually lower the risk of heart disease or even dementia. But the new study upends this narrative, providing evidence that any amount of drinking, even what many would consider negligible, increases the risk of dementia. The researchers found that a threefold increase in the number of alcoholic drinks per week led to a 15% higher risk of developing dementia, while a doubling of the genetically predicted risk of alcohol use disorder was linked to a 16% higher risk.
The research team took a two-pronged approach. First, they analyzed observational data to see if there was a relationship between self-reported alcohol use and the risk of developing dementia. At first glance, this analysis seemed to support prior findings: light or moderate drinkers appeared to have a lower risk of dementia compared to non-drinkers and heavy drinkers. But as the researchers dug deeper, they realized this might be misleading. Some non-drinkers may have previously been heavy drinkers, and their higher risk of dementia could be a lingering effect of past habits, not abstinence itself.
To untangle correlation from causation, the researchers turned to genetic data. This approach, often called Mendelian randomization, uses genetic variants as proxies for lifelong exposure to certain behaviors—in this case, alcohol consumption. The genetic analysis revealed a continuous, monotonic increase in dementia risk with greater alcohol intake. In other words, the more someone drank, the higher their risk, with no evidence of a protective effect at any level of consumption.
Dr. Stephen Burgess, a statistician from Cambridge who contributed to the study, emphasized that the findings apply to everyone, not just those with a genetic predisposition. "For anyone who chooses to drink, our study suggests that greater alcohol consumption leads to higher risk of dementia," he said, as reported by Deseret News.
These conclusions are bolstered by brain imaging studies, which have shown that even moderate alcohol intake is associated with smaller gray matter volume and increased iron deposits in the brain—both of which are linked to neurodegenerative diseases like Alzheimer’s and Parkinson’s. As The Washington Post highlighted, these harmful brain changes can be detected even at low levels of alcohol consumption over time.
Interestingly, the study also found that people who later developed dementia often reduced their alcohol intake before their diagnosis. This suggests that previous findings touting the benefits of moderate drinking may have been confounded by the fact that people were already experiencing early, undiagnosed symptoms of dementia and cut back on alcohol as a result—not because drinking was protecting them in the first place.
The implications of these findings are far-reaching. Alcohol consumption is deeply woven into many cultures and social rituals, and public health guidelines have often sent mixed messages. The World Health Organization has already concluded that there is no safe level of alcohol consumption. Yet, as Deseret News reported, the U.S. Dietary Guidelines continue to suggest that moderate drinking might provide some slight health benefits—a position increasingly at odds with the bulk of scientific evidence and the policies of many other high-income countries.
Public health authorities in the UK, for instance, have taken a firmer stance. The UK’s National Health Service recommends regular "drink-free days" each week and has even launched an app to help people cut back. "Cutting back on booze can be a really effective way to improve your health, boost your energy, lose weight and save money," the NHS advises, as cited by Deseret News.
Alcohol’s impact on health goes far beyond dementia. It has already been linked to an increased risk of several cancers, including breast and colorectal cancer, and can disrupt sleep patterns. According to Deseret News, alcohol-related deaths in the U.S. are on the rise, and while the risk is higher the more someone drinks, there’s “no safe amount.” For about one in five people, drinking leads to significant alcohol use disorder, but others may develop related health problems even without meeting the criteria for addiction.
There is, however, a silver lining in the research. As The Washington Post noted, studies of heavy drinkers who quit alcohol have shown that they can recover some cognitive function and even regain brain volume. This suggests that it’s never too late to make a change for the better, and cutting back—or quitting altogether—can yield real benefits.
In the end, the message from this new wave of research is unequivocal. As Dr. Topiwala and her colleagues put it, "Our study findings support a detrimental effect of all types of alcohol consumption on dementia risk, with no evidence supporting the previously suggested protective effect of moderate drinking." The study’s authors are calling for stronger preventive strategies at the population level to reduce alcohol consumption and, in turn, lower the risk of dementia across society.
With the science now pointing firmly in one direction, it may be time for individuals—and policymakers—to rethink the role of alcohol in our lives and consider whether even that occasional toast is worth the risk.