The days of thinking one or two drinks don’t harm your health are gone. In 2023, the World Health Organization confirmed that ‘No level of alcohol consumption is safe for our health’. The more you drink, the more you are prone to deleterious health risks. A new study has found that consuming eight or more alcoholic drinks per week may significantly increase the risk of brain damage.
The study, led by Alberto Fernando Oliveira Justo, PhD, of the University of Sao Paulo Medical School in Brazil, found that having eight or more drinks a week is linked to memory and thinking difficulties. The study is published in Neurology, the medical journal of the American Academy of Neurology. The new research, however, does not prove that heavy drinking causes brain injury, it only shows an association.
“Heavy alcohol consumption is a major global health concern linked to increased health problems and death. 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 author Alberto Fernando Oliveira Justo, PhD, of the University of Sao Paulo Medical School in Brazil said in a statement.
Alcohol and the brain
To understand the effects of alcohol on the brain, the researchers studied 1,781 people who had an average age of 75 at death. All had brain autopsies. The researchers looked for signs of brain injury including tau tangles and hyaline arteriolosclerosis.
Hyaline arteriolosclerosis is a condition that causes the small blood vessels to narrow, becoming thick and stiff. This makes it harder for blood to flow, which can damage the brain over time. It appears as lesions, areas of damaged tissue in the brain.
Researchers also measured brain weight and the height of each participant. The family members answered about the participants’ alcohol consumption.
For a better understanding, the participants were placed 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. One drink was defined as 14gms of alcohol, which is about 350 milliliters (ml) of beer, 150 ml of wine or 45 ml of distilled spirits.
The researchers found that people who never drank had 40% had vascular brain lesions. The moderate drinkers had 45% vascular brain lesions, and in heavy drinkers, it was 44%, while the former heavy drinkers had 50%.
After considering 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 were at 60% risk.
The study also revealed that heavy and former heavy drinkers had higher chances of developing tau tangles, a biomarker associated with Alzheimer’s disease, with 41% and 31% higher odds, respectively.
Also, former heavy drinkers had a lower brain mass ratio, which is a smaller proportion of brain mass compared to body mass, and worse cognitive abilities. In addition to brain injuries, they also had impaired cognitive abilities. They 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. Understanding these effects is crucial for public health awareness and continuing to implement preventive measures to reduce heavy drinking,” Justo said.
