Researchers find strong links between alcohol abuse and brain injury, premature death, and impaired reasoning.
The study, published in Neurology, the medical journal of the American Academy of Neurology, does not prove that excessive alcohol consumption causes brain damage; it only shows an association.
A study from the University of São Paulo (Brazil), which analyzed the association between alcohol consumption and age-related neuropathological outcomes in a population-based study, shows that heavy drinkers die 13 years earlier than those who never drank.
The study, published in Neurology, the medical journal of the American Academy of Neurology, does not prove that excessive alcohol consumption causes brain injury; it only shows an association. However, it found that heavy drinkers—defined as those who consume eight or more alcoholic drinks per week—have a higher risk of developing brain injuries known as hyaline arteriolosclerosis, which are associated with memory and reasoning problems.
Hyaline arteriolosclerosis is a condition that causes the narrowing of small blood vessels, making them thick and stiff. This restricts blood flow and, over time, can damage the brain. It appears as lesions—areas of damaged brain tissue.
“Excessive alcohol consumption is a major global health issue, linked to increased health problems and deaths. We analyzed how alcohol affects the brain as people age. Our research shows that heavy alcohol use is harmful to the brain and can lead to memory and thinking issues,” explained the study’s author, Dr. Alberto Fernando Oliveira Justo, from the Faculty of Medicine at the University of São Paulo (Brazil).
The study included 1,781 people with an average age of 75 at the time of death. All underwent brain autopsies. Researchers examined brain tissue for signs of brain damage, such as tau tangles and hyaline arteriolosclerosis. They also measured each participant’s brain weight and height.
Participants were divided into four groups:
- 965 people who never drank
- 319 moderate drinkers who consumed seven or fewer drinks per week
- 129 heavy drinkers who consumed eight or more drinks per week
- 368 former heavy drinkers
Researchers defined one drink as containing 14 grams of alcohol, equivalent to about 350 milliliters (ml) of beer, 150 ml of wine, or 45 ml of distilled liquor.
Among those who never drank, 40% showed vascular brain lesions. Among moderate drinkers, 45% had brain lesions. Among heavy drinkers, 44% had them. Among former heavy drinkers, 50% showed vascular brain damage.
After adjusting for factors that could affect brain health—such as age at death, smoking, and physical activity—heavy drinkers were 133% more likely to have vascular brain lesions compared to those who never drank. Former heavy drinkers were 89% more likely, and moderate drinkers 60% more likely.
Researchers also found that heavy and former heavy drinkers were more likely to develop tau tangles, a biomarker associated with Alzheimer’s disease—by 41% and 31% respectively.
Past excessive alcohol consumption was associated with a lower brain mass ratio (brain mass relative to body mass) and poorer cognitive abilities. No relationship was found between moderate or excessive alcohol consumption and brain mass ratio or cognitive abilities. However, cognitive impairments were observed only among former heavy drinkers.
Researchers also discovered that heavy drinkers died, on average, 13 years earlier than those who never drank.
“We found that excessive alcohol consumption is directly linked to signs of brain damage, which can cause long-term effects on brain health, potentially impacting memory and reasoning abilities,” said Justo. “Understanding these effects is crucial for public health awareness and for continuing to implement preventive measures to reduce excessive alcohol consumption.”
One limitation of the study was that it did not assess participants before death and lacked information on the duration of alcohol use and cognitive abilities.
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