Drinking any alcohol can increase dementia risk, Oxbridge researchers find
Experts found non-drinkers also developed a risk of getting the condition
A study led by Cambridge and Oxford researchers has found drinking any amount of alcohol could increase the risk of developing dementia.
Researchers also suggest that cutting down alcohol consumption across the population could "play a significant role in dementia prevention".
Data from 559,559 people involved in the UK Biobank and US Million Veteran Programme was analysed by experts at the University of Cambridge, University of Oxford and Yale University.
"The random nature of genetic inheritance allows us to compare groups with higher and lower levels of alcohol drinking in a way that allows us to make conclusions that untangle the confusion between correlation and causation," Dr Stephen Burgess, statistician at the University of Cambridge, said:
"Our findings do not only hold for those who have a particular genetic predisposition, but for anyone who chooses to drink, our study suggests that greater alcohol consumption leads to higher risk of dementia."
Non-drinkers had higher risk of dementia
During the follow-up period, some 14,540 people developed dementia.
Researchers found that non-drinkers and heavy drinkers, who consumed 40 or more drinks a week, had a 41% higher risk of developing dementia compared to light drinkers, who had fewer than seven alcoholic drinks a week.
This rose to a 51% risk among those who were alcohol-dependent.
Researchers also performed genetic analysis using data from genome-wide association studies of dementia, involving 2.4 million people.
Three measures related to alcohol consumption were used to explore the impact on dementia risk.
These were self-reported weekly drinks, problematic "risky" drinking, and alcohol dependency.
'No support' that little alcohol benefits brain health - expert
"Our findings challenge the common belief that low levels of alcohol are beneficial for brain health," Dr Anya Topiwala, senior clinical researcher at Oxford Population Health and consultant psychiatrist, said:
"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."
According to Alzheimer's Society, about 982,000 people in the UK have dementia.
By 2040, about 1.4 million people in the UK could be living with the condition.