Any level of alcohol consumption could increase the risk of dementia, according to a study by researchers at the University of Oxford, Yale University and the University of Cambridge. While heavy drinking has already been linked to increased dementia risk, the new research ‘challenges previous suggestions’ that light-to-moderate drinking could have a protective effect against the condition.
The study, which is published in the journal BMJ Evidence-Based Medicine, is the most comprehensive so far to look at alcohol consumption and dementia risk, says Oxford’s Nuffield Department of Population Health. It combined observational data from more than half a million people in two diverse population studies, as well as investigating links between genetically predicted likelihood of alcohol use and alcohol use disorder in almost 2.5m participants across 45 separate studies. This approach helped to ‘overcome some of the difficulties in distinguishing correlation from causation’, the researchers state.
The study revealed a ‘continuously increasing trend’ of higher dementia risk with higher levels of drinking – suggesting that ‘any level of alcohol consumption increases the risk of dementia, with no evidence that drinking alcohol may have a protective effect’. A three times higher increase in the number of drinks per week raised the risk of dementia by 15 per cent, say the researchers.
‘Our findings challenge the common belief that low levels of alcohol are beneficial for brain health,’ said lead author Dr Anya Topiwala. ‘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.’
A research project looking at how people with alcohol or drug issues are looked after in care homes was launched earlier this month by the Care Quality Commission in partnership with the University of Bedfordshire.
Alcohol use and risk of dementia in diverse populations: evidence from cohort, case–control and Mendelian randomisation approaches available here