September 23, 2025

expert reaction to study looking at the association between any amount of alcohol consumption and risk of dementia

A study published in BMJ Evidence Based Medicine looks at the association between alcohol consumption and dementia risk.

Prof Sir David Spiegelhalter, Emeritus Professor of Statistics, University of Cambridge, said:

“The reporting of this study is misleading.  The authors say that “genetic analysis showed a monotonic increasing dementia risk with increased alcohol intake.”. This is untrue.  The relationship is with genetically predicted alcohol intake – the actual alcohol consumption is not part of this analysis.  And those genetic predictions rely on many unverifiable assumptions, as the authors acknowledge.”

Prof Tara Spires-Jones, Director of the Centre for Discovery Brain Sciences at the University of Edinburgh, Group Leader in the UK Dementia Research Institute, and Past President of the British Neuroscience Association said:

“This study by Topiwala and colleagues at Oxford examining the relationship between alcohol use and risk of developing dementia is well-conducted.  The authors looked at data from over 500,000 people who provided self-reports of how much they drank and compared this to their risk of developing dementia over time.  Further they examined genetics from over 2 million people and compared genetic markers associated with alcohol use and genetic markers associated with increased risk.

“In both parts of the study, scientists observed that higher reported or predicted alcohol use was associated with increased risk or predicted risk of dementia.  In the self-reporting study, people who reported consuming small amounts of alcohol (less than 7 drinks per week) had lower risk than heavy drinkers (more than 40 drinks per week).  Interestingly, in this part of the study, non-drinkers and people who reported never drinking actually had similar risk of dementia to people who drank heavily.

“In the genetic study, genes predicting higher alcohol consumption were associated with genes predicting higher dementia risk.  Unlike the self-reporting part of the study, genes predicting low alcohol intake were not associated with genes predicting low dementia risk. The authors attribute the difference between the parts of the study to people reducing alcohol intake in the early stages of dementia, but this does not explain the increased risk in people who report never drinking.

“Authors rightly acknowledge several important limitations of the study. Self-reported alcohol use may not be accurate, particularly if people have memory problems in early stages of dementia, and the genetic markers used as predictors of both alcohol intake and dementia are not perfect.  

“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, and fundamental neuroscience work has shown that alcohol is directly toxic to neurons in the brain.”

‘Alcohol use and risk of dementia in diverse populations: evidence from cohort, case–control and Mendelian randomisation approaches’ by Topiwala et al. was published in BMJ Evidence Based Medicine at 23:30 UK time on Tuesday 23th September. 

DOI: 10.1136/ bmjebm-2025-113913

Declared interests

Prof Sir David Spiegelhalter “No conflicts of interest”

Prof Tara Spires-Jones “I have no conflicts with this study but have received payments for consulting, scientific talks, or collaborative research over the past 10 years from AbbVie, Sanofi, Merck, Scottish Brain Sciences, Jay Therapeutics, Cognition Therapeutics, Ono, and Eisai. I am also Charity trustee for the British Neuroscience Association and the Guarantors of Brain and serve as scientific advisor to several charities and non-profit institutions.”