Data from more than 2 million people, including UK Biobank participants, casts doubt on the belief that a drink a day is good for brain health.
Summary
New research challenges previous studies that seemed to suggest that the occasional alcoholic drink helps to ward off dementia. Instead, any amount of alcohol increases dementia risk, show data from more than 2 million people, including UK Biobank participants.
“I’ve never really been able to understand why a little bit of poison is good for you,” says Anya Topiwala from the University of Oxford, UK, whose research challenges the notion that the occasional alcoholic drink helps to ward off dementia. Instead, any amount of alcohol seems to increase dementia risk, her team’s analysis suggests.
“My advice is always to try to cut down, even if you don’t stop drinking,” Topiwala says. “Probably you are doing your brain a favour.”
The myth of safe drinking
While heavy drinking has been linked to higher dementia risk, things haven’t been so clear for people who only have alcohol occasionally. Some research suggests that light drinking makes it less likely to develop dementia than not drinking at all.
My advice is always to try to cut down, even if you don’t stop drinking. Probably you are doing your brain a favour.
Dr Anya Topiwala, University of Oxford, UK
Initially, in their analysis of more than half a million people’s drinking habits, Topiwala and her team found something similar: both people who have more than 40 alcoholic drinks a week and non-drinkers have a higher risk of dementia than people who said they had fewer than seven drinks a week.
“The issue is that the kind of people that tend to drink moderately are at lower risk of dementia – it could be nothing to do with the drinking,” Topiwala explains. “They tend to have higher levels of education, for instance, and they do better at memory tests.”
This type of analysis also can’t account for how cognitive decline can change people’s drinking habits. Having early-stage dementia, even before it’s diagnosed, might be the reason someone cuts back on alcohol or stops drinking entirely.
Genetics reveal alcohol’s impact on brain health
To disentangle the links between drinking and dementia, Topiwala’s team looked at genetic information from 2.4 million people, including UK Biobank participants. “We looked at dementia in a group of people with high genetic risk or low genetic risk of drinking,” Topiwala explains. While drinking habits are heavily shaped by our social environment, “your genetics explain a small proportion of the variance of how much you drink – enough to be able to use this technique in large samples”, she says.
In this analysis, higher genetic predisposition to drinking was linked to a greater likelihood of developing dementia. The team found no evidence that (genetically predicted) light drinking protects from dementia.
Neither part of the study can conclusively prove that alcohol use directly causes dementia, but this adds to a large amount of similar data showing associations between alcohol intake and increased dementia risk.
Professor Tara Spires-Jones, University of Edinburgh, UK
“Neither part of the study can conclusively prove that alcohol use directly causes dementia, but this adds to a large amount of similar data showing associations between alcohol intake and increased dementia risk,” dementia researcher Tara Spires-Jones from the University of Edinburgh, UK, told the Science Media Centre.
“I think there’s quite a substantial contribution of drinking to dementia risk in this country that may be underestimated,” Topiwala says. That doesn’t mean she wants to scare people into abstinence. “We’re trying to give people the best evidence so they can make an informed decision,” she explains. “It’s a risk-benefit trade-off: most of us get in a car even though there’s a risk of having an accident. As long as you’re not drinking large amounts, I wouldn’t panic too much.”
Related publication
- BMJ Evidence-Based Medicine, September 2025
