Brains of heavy drinkers show more damage, especially lesions and Alzheimer's-linked tau tangles. The risks persisted even for those who had quit drinking. Credit: SciTechDaily.com
Eight or More Drinks per Week Linked to Signs of Brain Injury
Heavy drinking may leave a damaging legacy in the brain. People who consumed eight or more alcoholic drinks weekly were more likely to have vascular brain lesions and signs of neurodegeneration, including tau tangles tied to Alzheimer's
Heavy Drinking Tied to Brain Damage Risk
People who regularly drink eight or more alcoholic beverages per week may face a higher risk of developing brain lesions linked to memory and thinking problems, according to a study published today (April 9, 2025) in Neurology , the journal of the American Academy of Neurology. The study found an association between heavy drinking and signs of brain injury but did not prove that alcohol directly causes the damage.
The specific type of brain injury identified is called hyaline arteriolosclerosis, a condition where small blood vessels in the brain become thick, stiff, and narrow. This restricts blood flow and can lead to tissue damage, which appears as lesions in the brain.
Alcohol's Impact on Aging Brains
“Heavy alcohol consumption is a major global health concern linked to increased health problems and death,” said study author Alberto Fernando Oliveira Justo, PhD, of University of Sao Paulo Medical School in Brazil. “We looked at how alcohol affects the brain as people get older. Our research shows that heavy alcohol consumption is damaging to the brain, which can lead to memory and thinking problems.”
Study Overview and Brain Autopsy Details
The research was based on brain autopsies from 1,781 individuals, who had an average age of 75 at the time of death.
Researchers examined brain tissue to look for signs of brain injury including tau tangles and hyaline arteriolosclerosis. They also measured the brain weight and the height of each participant.
Family members answered questions about participants' alcohol consumption.
Researchers then divided the participants into four groups: 965 people who never drank, 319 moderate drinkers who had seven or fewer drinks per week; 129 heavy drinkers who had eight or more drinks per week; and 368 former heavy drinkers. Researchers defined one drink as having 14 grams of alcohol, which is about 350 milliliters (ml) of beer, 150 ml of wine or 45 ml of distilled spirits.
Comparing Brain Lesions Across Drinking Levels
Of those who never drank, 40% had vascular brain lesions. Of the moderate drinkers, 45% had vascular brain lesions. Of the heavy drinkers, 44% had vascular brain lesions. Of the former heavy drinkers, 50% had vascular brain lesions.
After adjusting for factors that could affect brain health such as age at death, smoking, and physical activity, heavy drinkers had 133% higher odds of having vascular brain lesions compared to those who never drank, former heavy drinkers had 89% higher odds, and moderate drinkers, 60%.
Tau Tangles and Cognitive Impacts
Researchers also found heavy and former heavy drinkers had higher odds of developing tau tangles, a biomarker associated with Alzheimer's disease, with 41% and 31% higher odds, respectively.
Former heavy drinking was associated with a lower brain mass ratio, a smaller proportion of brain mass compared to body mass, and worse cognitive abilities. No link was found between moderate or heavy drinking and brain mass ratio or cognitive abilities.
Justo noted that, in addition to brain injuries, impaired cognitive abilities were observed only in former drinkers.
Earlier Death and Long-Term Brain Damage
Researchers also found that heavy drinkers died an average of 13 years earlier than those who never drank.
“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,” said Justo. “Understanding these effects is crucial for public health awareness and continuing to implement preventive measures to reduce heavy drinking.”
A limitation of the study was that it did not look at participants before death and did not have information on the duration of alcohol consumption and cognitive abilities.
Reference: 9 April 2025, Neurology
The study was supported by The São Paulo Research Foundation.