Alcohol is notoriously bad for health, and a recent study might add “long-term effects on brain health” to the growing list of ways drinking can cause harm.
The research, led by scientists at the University of São Paulo in Brazil, investigated the impact of regular drinking by examining brain autopsy data from 1,781 individuals, correlating findings with their reported drinking habits.
After adjusting for sociodemographic and clinical variables, like smoking and physical activity, the team found that the heaviest drinkers had a 133 percent higher risk of developing vascular brain lesions compared to non-drinkers.
Those who had been heavy drinkers but since given it up had an 89 percent higher risk, while moderate drinkers had a 60 percent higher risk.
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Heavy and former heavy drinkers also seemed to have higher odds of other neurological damage than non-drinkers. Heavy drinkers were found to have a 41 percent higher risk of tau protein tangles – a biomarker of Alzheimer’s disease – while former heavy drinkers still had a 31 percent higher risk.
Heavy drinkers also seemed to die 13 years earlier, on average, than non-drinkers.
It’s important to note, however, that the study only shows an association – it doesn’t confirm that heavy drinking directly causes the kind of brain damage seen.
The data was collected as part of Brazil’s Biobank for Aging Studies project, which examines the brains of people post-mortem. In this case, the researchers searched for signs of brain tissue injury, including lesions from hyaline arteriolosclerosis and tau tangles from Alzheimer’s disease.
To determine the participants’ drinking habits, their next of kin filled out a detailed questionnaire about what their alcohol consumption was like three months before their death.
The researchers divided the cohort into four groups based on how many drinks they consumed per week, with one drink equaling 14 grams of alcohol. They classified 965 people as never-drinkers, 319 as moderate drinkers (seven or fewer drinks per week), 129 as heavy drinkers (eight or more per week), and 368 as former heavy drinkers.
“We found heavy drinking is directly linked to signs of injury in the brain, and this can cause long-term effects on brain health, which may impact memory and thinking abilities,” says pathophysiologist Alberto Fernando Oliveira Justo from the University of São Paulo.
“Understanding these effects is crucial for public health awareness and continuing to implement preventive measures to reduce heavy drinking.”
Along with the increased risks of brain lesions and tau tangles, the team found that former heavy drinkers were more likely to have a lower brain mass-to-body height ratio, and impaired cognitive abilities as judged by their next of kin during an interview. Strangely though, these links weren’t found for moderate or heavy drinkers.
The researchers acknowledge the limitations of the study: being a cross-sectional analysis, it can’t establish direct causality. They also weren’t able to follow patients before death to get more details on their alcohol consumption and other lifestyle factors over time – the duration and changes in their drinking habits couldn’t be accounted for.
Still, the association adds another concern to the long list of potential health troubles that alcohol consumption could trigger, even in moderation. The stuff is already linked to higher risks of heart troubles, several types of cancer, and slower healing.
The research was published in the journal Neurology.
