Drinking more than eight alcoholic drinks per week is linked to a higher risk of brain lesions called hyaline arteriolosclerosis, which are linked to memory and thinking problems. The corresponding study was published in Neurology.
"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,” said study author Alberto Fernando Oliveira Justo, PhD of the University of Sao Paulo Medical School in Brazil in a press release.
For the study, the researchers analyzed brain tissue from 1, 781 participants who died at an average age of 75 years old. They analyzed the samples for signs of brain injury like tau tangles and hyaline arteriolosclerosis, a condition in which small blood vessels narrow and become thick and stiff, reducing blood flow over time causing brain damage.
The participants were divided into four groups: 965 who never drank, 319 who were moderate drinkers having seven or fewer drinks per week, 129 who were heavy drinkers and had eight or more drinks per week, and 368 heavy drinkers. One drink was defined as around 14 grams of alcohol, equivalent to around 350 ml of beer.
Ultimately, they found moderate, heavy, and former heavy consumption were linked to higher rates of hyaline arteriolosclerosis than never consuming alcohol. Only heavy and former heavy alcohol consumption were linked to neurofibrillary tangles.
After adjusting for multiple potential confounders, including age at death, smoking, and physical activity, heavy drinkers were 133% more likely to have vascular brain lesions than those who never drank. Former heavy drinkers were 89% more likely to have lesions, and moderate drinkers: 60%.
Former heavy drinking was also linked to a lower brain mass ratio, a smaller proportion of brain mass relative to body mass, and worse cognitive abilities. The researchers found no link between moderate or heavy driving and brain mass ratio or cognitive abilities. Heavy drinkers were found to die an average of 13 years before those who never drank.
The researchers noted that lack of longitudinal data on the duration of alcohol consumption and cognitive abilities limits how the findings may be interpreted.
"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,” said Justo.
Sources: Science Daily, Neurology
