A new study exploring the relationship between alcohol consumption and dementia risk is warning that there is no safe limit of drinks when it comes to potential risks.
A study published in the journal BMJ Evidence-Based Medicine on Tuesday found that any amount of alcohol consumption can lead to an increased risk of dementia.
The report notes that it is in contrast to previous research, which has suggested that moderate and light drinking might have a protective effect on dementia as opposed to no consumption.
“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,” said Anya Topiwala, senior clinical researcher at the University of Oxford, who led the study.
“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.”
Increasing the amount of alcohol consumption by three times can lead to a 15 per cent higher risk of developing dementia. For example, if a person increases their weekly drinks from one to three, that increases their dementia risk by 15 per cent, the study said.
For anyone predisposed to developing an alcohol dependency, even a twofold increase in alcohol consumption would lead to a 16 per cent increase in dementia risk.
Daniel Levey, research health scientist at Yale University and one of the co-authors of the study, said previous research may be skewed by changing drinking habits.
“People could be stopping their drinking and show up as non-drinkers, but have really high risk of dementia,” he said.
The study, led by researchers from the University of Oxford, Yale University and the University of Cambridge, combined observations of half a million participants from the US Million Veteran Program and UK Biobank with genetic analysis.
“(Genetic variation) changes drastically how you can break down alcohol in your system,” Levey said.
“We look at some of these genetic associations and alcohol-related behaviour as a way to try and identify a causal relationship between alcohol-related behaviours and then dementia outcomes,” he said.
While observational analyses confirmed previous studies that said low and moderate drinking is associated with lower risk of dementia when compared with non-drinking, genetic analyses revealed a different story.
The study found higher dementia risk with greater alcohol intake, suggesting that any level of alcohol consumption increases the risk of dementia.
“Genetic analyses provided evidence that alcohol consumption in general, as well as problematic drinking, increases dementia risk,” the report said, adding that there was no evidence that light or moderate drinking has any protective effect.
The report categorized alcohol drinkers into heavy (40 or more drinks per week), moderate (seven to 14 drinks per week) and light (less than seven drinks per week). When it comes to dementia risk, there is no safe limit, the study found.
“In a heavy drinker, we expect there to be much more negative association,” Levey said.
“The key take home is that there may not be any protective element to drinking alcohol at all, and that really potentially any exposure may increase your risk.”
According to Health Canada’s latest alcohol guidelines, women should avoid having more than 10 drinks a week, while men should avoid having more than 15.
“People just need to weigh the risks,” Levey said.
“This is emerging data. I think people just need to be well informed that light drinking may not be a healthy decision.”