Drinking any amount of alcohol raises dementia risks, study warns

Alcohol raises the risk of dementia regardless of whether people are genetically predisposed to the neurodegenerative condition, a large new study suggests.

It is the latest research to confirm that even moderate alcohol consumption can pose health risks. Despite the occasional headline about the benefits of low-level drinking, research has repeatedly shown that no amount of alcohol is safe for our health.

“For anyone who chooses to drink, our study suggests that greater alcohol consumption leads to higher risk of dementia,” Stephen Burgess, a statistician at the University of Cambridge, said in a statement.

The study, which was published in the journal BMJ Evidence-Based Medicine, included about 560,000 people in the United Kingdom and the United States who were followed over several years, as well as genetic data for about 2.4 million people.

In the first part of the study, researchers asked people how much they drank and then determined the relationship between alcohol and dementia risks. They also analysed genetic markers tied to alcohol use to take into account its cumulative effect over the course of people’s lives.

The higher someone’s genetic risks tied to alcohol, the higher their dementia risks, the study found. If someone had three drinks per week, for example, they were 15 per cent more likely to develop dementia than someone who had one drink per week.

“Genetic evidence offers no support for a protective effect [from alcohol] – in fact, it suggests the opposite,” said Anya Topiwala, one of the study’s authors and a senior clinical researcher at the University of Oxford.

The study does not conclusively prove that drinking alcohol causes dementia, only that the two are linked, cautioned Tara Spires-Jones, director of the Centre for Discovery Brain Sciences at the University of Edinburgh. She was not involved in the study.

However, “fundamental neuroscience work has shown that alcohol is directly toxic to neurons in the brain,” she added in a statement.

In one previous study using brain scans, researchers found that drinking one or two units of alcohol per day was associated with reductions in brain volume and changes to its structure, which may be linked to memory loss and dementia.

The latest study’s authors said their findings add to the growing body of evidence that cutting out alcohol could have serious health benefits.

“Reducing alcohol consumption across the population could play a significant role in dementia prevention,” Topiwala said.