People who consume eight or more alcoholic drinks a week are more likely to show signs of brain injury, including lesions and tau tangles associated with memory loss and dementia, according to a new study published in Neurology, the medical journal of the American Academy of Neurology.

The study also noted that heavy drinkers died an average of 13 years earlier than non-drinkers.

Researchers found that heavy drinking is associated with a condition called hyaline arteriolosclerosis, where small blood vessels in the brain narrow and stiffen, reducing blood flow and damaging brain tissue over time. These lesions are known to impact memory and thinking skills.  

“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 the 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.”

Brain autopsy

The study looked at brain autopsy results from 1,781 individuals with an average age of 75 at the time of death. Participants were divided into four groups: 965 people who never drank, 319 moderate drinkers (seven or fewer drinks per week), 129 heavy drinkers (eight or more drinks per week), and 368 former heavy drinkers. One drink was defined as 14 grams of alcohol — equivalent to about 350 ml of beer, 150 ml of wine, or 45 ml of spirits.

Among those who never drank, 40% had vascular brain lesions. That number rose to 44% among heavy drinkers and 50% among former heavy drinkers. After adjusting for other health factors like smoking and physical activity, researchers found that heavy drinkers had 133% higher odds of having vascular brain lesions compared to non-drinkers. Former heavy drinkers had 89% higher odds, and moderate drinkers 60%.

The study also found that both heavy and former heavy drinkers were more likely to develop tau tangles — twisted fibers inside brain cells that are associated with Alzheimer’s disease — with 41% and 31% higher odds, respectively.

“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,” Justo said.

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