Key points from article :
A new large-scale study has found that any level of alcohol consumption may increase the risk of dementia, overturning the long-held belief that light or moderate drinking could protect brain health. The research, published in BMJ Evidence-Based Medicine, was led by Dr. Anya Topiwala of the University of Oxford, alongside collaborators from Yale University and the University of Cambridge. Their findings suggest there is no safe level of alcohol intake when it comes to dementia risk.
The team analysed data from over half a million participants in two major population studies, the UK Biobank and the US Million Veteran Program. They combined these observations with genetic data from 2.4 million individuals across 45 studies to better distinguish between correlation and causation. While observational data initially appeared to show that moderate drinkers had a lower risk of dementia compared to non-drinkers, further analysis revealed this was likely due to some non-drinkers having quit alcohol after years of heavy drinking, which itself raised dementia risk.
Genetic analyses told a different story, showing a consistent trend: the more alcohol a person consumed, the greater their risk of dementia. Doubling a person’s genetic risk for alcohol use disorder increased dementia risk by 16%, while tripling the number of drinks consumed per week raised dementia risk by 15%. This provided strong evidence that alcohol consumption itself, even in small amounts, directly contributes to dementia risk rather than protecting against it.
The researchers stress that their work carries important public health implications. Dr. Topiwala noted that cutting back on alcohol could play a significant role in dementia prevention across the population. Co-author Dr. Stephen Burgess highlighted that genetic evidence helps untangle the confusion caused by earlier observational studies, while Professor Joel Gelernter of Yale emphasized that medical advice once supporting light drinking for brain health is now outdated. Together, their results strengthen the case for reducing alcohol use to safeguard long-term cognitive health.
