April 30, 2025
Heavy drinking can take a toll on the body, raising the risk for heart disease, various forms of cancer, strokes, liver damage and many other ills. It can also raise the risk for Alzheimer’s disease and other forms of dementia, many studies show.
But how much is too much when it comes to alcohol consumption and brain health? Scientists in Brazil report that having eight or more drinks a week is tied to signs of brain damage and an increased risk of cognitive decline.
“We looked at how alcohol affects the brain as people get older,” said study author Alberto Fernando Oliveira Justo of the University of Sao Paulo Medical School. “Our research shows that heavy alcohol consumption is damaging to the brain, which can lead to memory and thinking problems.”
For the study, the researchers used data from a large-scale study of aging and looked at the brains of 1,781 men and women who had died at an average age of 75. During autopsies, doctors examined brain tissue to look for signs of injury. Among the brain abnormalities, or lesions, they identified were tau tangles, spaghetti-like strings of proteins that are a hallmark of Alzheimer’s disease. They also looked for signs of hyaline arteriolosclerosis, a vascular condition that causes small blood vessels to narrow, becoming thick and stiff. This condition impairs blood flow and can damage the brain over time, raising the risk of dementia.
In addition, the researchers surveyed family members to assess the drinking habits of those who had died. They divided them into four groups: 965 who never drank; 319 who were moderate drinkers, defined as having seven or fewer drinks a week; 129 who were heavy drinkers, having eight or more drinks a week; and 368 former heavy drinkers. A drink is generally considered to contain 14 grams of alcohol, equivalent to about 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of liquor.
The researchers found that heavy and former heavy drinkers had higher odds of developing tau tangles, putting them at increased risk of developing Alzheimer’s disease. Compared to nondrinkers, heavy drinkers were 41 percent more likely to have high levels of tau tangles, and former heavy drinkers were 31 percent more likely to have high levels of tau tangles.
Drinkers were also more likely to have the vascular brain lesions of hyaline arteriosclerosis. After adjusting for factors that could affect brain health such as age, whether someone smoked and how much physical activity they got, the researchers concluded that heavy drinkers had 133 percent higher odds of having vascular brain lesions compared to those who never drank, former heavy drinkers had 89 percent higher odds, and moderate drinkers had 60 percent higher odds.
Researchers also found that former heavy drinking was associated with worse performance on memory and thinking tasks, and that heavy drinkers died an average of 13 years earlier than those who never drank. The findings were published in Neurology, the medical journal of the American Academy of Neurology.
“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,” Dr. Justo said. “Understanding these effects is crucial for public health awareness and continuing to implement preventive measures to reduce heavy drinking.”
Scientists continue to debate how much is too much when it comes to alcohol. Some studies suggest that moderate drinking may have benefits for brain health, although other studies have not found any links between moderate alcohol consumption and cognitive health. The U.S. Dietary Guidelines for Americans states that adults should limit consumption to one drink a day for women and two drinks a day for men, although concerns have also been raised about the connection between even moderate drinking and various types of cancer.
This study did not look at individual drinking patterns, such as whether someone drank every day or tended to binge drink on weekends. It also showed only an association between drinking and brain health and could not prove cause and effect. But a consensus seems to be emerging that heavy drinking can take a heavy toll on the brain. Moderation in most things, including alcohol use, is likely the best course to follow to help keep the brain in good working order as we age.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, PhD, of The Fisher Center lab at The Rockefeller University.
Source: Alberto Fernando Oliveria Justo, Regina paradela, Natalia Gomes Concalves; et al: “Association Between Alcohol Consumption, Cognitive Abilities, and Neuropathologic Changes: A Population-Based Autopsy Study.” Neurology, April 9, 2025
