Sep 25, 2025 12:00:00

Research results show that even small amounts of alcohol may increase the risk of dementia

In recent years,

research findings on the relationship between alcohol consumption and cognitive function have been mixed, with some finding that even moderate amounts of alcohol can accelerate the decline of cognitive function in the brain, while others have found that people who abstained from alcohol altogether in middle age are at a higher risk of dementia. A new study of over 500,000 adults in the UK and US has revealed some harsh results for heavy drinkers, showing that even small amounts of alcohol consumption may increase the risk of dementia.

Alcohol use and risk of dementia in diverse populations: evidence from cohort, case–control and Mendelian randomization approaches | BMJ Evidence-Based Medicine
https://ebm.bmj.com/content/early/2025/09/16/bmjebm-2025-113913

There May Be No Safe Amount of Booze When It Comes to Dementia Risk : ScienceAlert
https://www.sciencealert.com/there-may-be-no-safe-amount-of-booze-when-it-comes-to-dementia-risk

The international research team surveyed 559,559 adults aged 56 to 72 living in the UK and the US at the start of the study. Participants completed a questionnaire about their drinking habits and were then tracked for up to 15 years regarding their health.

During the follow-up period, 14,540 participants developed dementia and 48,034 died. The average follow-up period for participants in the UK was 12 years, while that for participants in the US was 4 years.

When the data was analyzed, a typical U-shaped graph was obtained, showing that 'non-drinkers and heavy drinkers have a high risk of dementia, while moderate drinkers have the lowest risk of dementia.' This result seems to suggest that 'moderate drinking reduces the risk of dementia,' but the research team points out that there is actually a pitfall in this graph.

According to the research team, the participants who answered that they never drank alcohol included those who were once heavy drinkers but stopped drinking for some reason, and those who stopped drinking because they experienced the early symptoms of dementia. In other words, the statistics were skewed.

To find further evidence, the research team used

Mendelian randomization analysis to analyze the association between alcohol consumption and dementia using genetic data from 2.4 million people. This approach uses 'genetic factors related to alcohol consumption' rather than data on actual drinking habits to predict alcohol consumption and analyze the association with dementia.

The graph below shows the predicted alcohol consumption (horizontal axis) and dementia risk (vertical axis) by Mendelian randomization analysis. The higher the predicted alcohol consumption, the higher the dementia risk, and even small amounts of alcohol consumption did not reduce the risk.

The research team said: 'Our findings confirm that all types of alcohol consumption have a detrimental effect on dementia risk. There is no evidence to support the previously suggested protective effect of moderate drinking.' 'Reducing the prevalence of alcohol use disorders could potentially reduce dementia cases by up to 16%. This highlights that reducing alcohol intake is a potential strategy for dementia prevention policy.'

This study has several limitations. First, the data on participants' drinking habits was self-reported, not scientifically measured, which may lead to inaccuracies. Second, while Mendelian randomization analysis is a useful tool, it does not directly record alcohol intake.

Tara Spiers-Jones, a neuroscientist at the University of Edinburgh who was not involved in the new study, said: 'Neither part of this study can conclusively prove that alcohol consumption directly causes dementia, but it adds to a large body of similar data showing an association between alcohol consumption and an increased risk of dementia. Basic neuroscience research shows that alcohol is directly toxic to neurons in the brain.'