Researchers studied data from millions of people and said that their findings challenge the common perception that drinking small amounts of alcohol can benefit the brain
Drinking any amount of alcohol could increase the risk of developing dementia, according to a new study.
The findings challenge the idea that light drinking could benefit brain health, researchers said. They also suggest that cutting down alcohol consumption across the population could “play a significant role in dementia prevention”. The study, led by experts at the University of Oxford, Yale University, and the University of Cambridge, looked at data from 559,559 people involved in the UK Biobank and US Million Veteran Programme.
During the follow-up period, some 14,540 people had developed dementia. Researchers found 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 (GWAS) 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.
Higher genetic risk for all three exposure levels was associated with an increased risk of dementia. Dr Anya Topiwala, senior clinical researcher at Oxford Population Health and consultant psychiatrist, said: “Our findings challenge the common belief that low levels of alcohol are beneficial for brain health.
“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.”
Dr Joel Gelernter, a professor at Yale University and senior author of the study, said the findings, published in BMJ Evidence Based Medicine, not only add to the understanding of the relationship between alcohol and dementia, but also have “clinical implications”. He added: “There was a time when medical knowledge seemed to support that light drinking would be beneficial to brain health, and this work adds to the evidence that this is not correct.”
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.
Dr Stephen Burgess, statistician at the University of Cambridge, said: “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.
“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.”
While Dr Leah Mursaleen, head of clinical research at Alzheimer’s Research UK, said: “This large-scale study adds further evidence that alcohol consumption is linked to an increased risk of dementia, with higher alcohol consumption increasing a person’s risk further. In contrast to other studies, the researchers found that even light alcohol consumption may also increase a person’s risk, when combined with genetic analysis.
“Further research is needed to gain a better understanding of the impact of alcohol use on brain health, and how intervention strategies may reduce dementia risk. With no treatments currently available on the NHS that can stop or slow the diseases that cause dementia, there has never been a more pressing need for practices to support good brain health.”