Study details and key findings

For the study, researchers analyzed autopsy data from the Biobank for Aging Studies at the University of São Paulo Medical School in Brazil, which was collected between 2004 and 2024. In total, the researchers analyzed data from 1,781 patients who were ages 50 or older at death. The average age at death was 74.9 years.

Using surveys from next of kin, the researchers measured the patients' cognitive function and alcohol consumption in the three months before their deaths.

Among the patients:

• 965 never consumed alcohol
• 319 consumed up to seven alcoholic drinks per week (moderate drinkers)
• 129 consumed eight or more alcoholic drinks per week (heavy drinkers)
• 368 were former heavy drinkers but stopped consuming alcohol before the last three months of their life

Overall, the researchers found that heavy drinkers and former heavy drinkers had an increased risk of neurofibrillary tangles, or clumps of tau protein that accumulate inside brain neurons and are associated with Alzheimer's disease. Heavy drinkers had a 41% increased risk, and former heavy drinkers had a 31% increased risk.

Moderate, heavy, and former heavy drinkers also had a higher risk of hyaline arteriolosclerosis, a condition that thickens the walls of small blood vessels in the brain, obstructing blood flow and causing brain damage over time. Moderate (44.6%), heavy (44.1%), and former heavy drinkers (50.2%) were also more likely to have vascular brain lesions than people who never drank (40%).

After adjusting for age, sex, heart disease, and other health conditions, the researchers found that heavy drinkers had a 133% increased risk of developing vascular brain lesions than those who never drank. Moderate drinkers also had a 60% increased risk while former heavy drinkers had an 89% increased risk.

Heavy drinkers were also more likely to die at an earlier age than those who never drank. On average, heavy drinkers died 13 years earlier than nondrinkers.

"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 Alberto Fernando Oliveira Justo, a researcher at the University of São Paulo Medical School and the study's lead author. "Understanding these effects is crucial for public health awareness and continuing to implement preventive measures to reduce heavy drinking."

Research has also been mixed on the potential benefits or risks associated with drinking. For example, a report published by the National Academies of Sciences, Engineering, and Medicine in January found that people who drank moderately had lower all-cause mortality and a lower risk of dying from cardiovascular disease.

However, another study from the American Cancer Society and the International Agency for Research on Cancer found that alcohol was associated with seven different cancers, including oral cavity, pharynx, larynx, colorectum, female breast, squamous cell carcinoma in the esophagus, and hepatocellular carcinoma in the liver. 

Former U.S. Surgeon General Vivek Murthy issued a report arguing that alcoholic beverages should carry warning labels about the link between alcohol consumption and cancer risk, similar to the warnings on cigarettes.

Overall, Wen said the "consensus is generally that less is better" when it comes to drinking alcohol.

"Where to draw the line on defining heavy alcohol use is not entirely clear," Wen said. "More and more research, including this study, are beginning to show that even alcohol usage within currently recommended guidelines could be associated with negative consequences."

However, Wen added that she thinks it's possible for people to have a healthy relationship with alcohol. To better assess your relationship with alcohol, Wen recommends trying out sobriety challenges like Dry January or Sober October.

"These experiences can help people take stock of exactly how much they are drinking, how they feel when they abstain, and when and why they drink," Wen said. And if there are potential warning signs of harmful drinking behavior, like drinking to hide negative feelings, people can seek help from their primary care provider or a mental health specialist.