Heavy alcohol use in adolescent nonhuman primates reduced the rate of brain growth by 0.25 milliliters per year for every gram of alcohol consumed per kilogram of body weight, according to researchers at Oregon Health & Science University. In humans, that would translate to four beers per day.

Chronic alcohol self-intoxication reduced the growth rate of brain, cerebral white matter and subcortical thalamus,” the researchers wrote.

In the study, published at eNeuro, the team of researchers studied the brains of 71 rhesus macaques from the Oregon National Primate Research Center that consumed alcohol using magnetic resonance imaging. The first thing the researchers had to do was characterize normal brain growth of rhesus macaques in adolescence (1mm/1.87 years) to then compare it with the growth of alcohol-consuming macaques.

Additionally, they also monitored their diet, daily schedules, physical activity, health care, and intake, in order to rule out other factors that tend to confound results in observational studies in humans. The results help corroborate previous research examining the effect of alcohol use on developing brain in people.

Human studies are based on self-reporting of underage drinkers,” said co-author Christopher Kroenke, associate professor in the Division of Neuroscience at the primate center. Our measures pinpoint alcohol drinking with the impaired brain growth.”

Previous research has shown the brain has a capacity to recover at least in part following the cessation of alcohol intake, said Tatiana Shnitko, research assistant professor in the Division of Neuroscience at the primate center and lead author of the study. However, it’s not clear whether there would be long-term effects on mental functions as the adolescent and young adult brain ends its growth phase. The next stage of research will explore that question.

This is the age range when the brain is being fine-tuned to fit adult responsibilities,” Shnitko said. “The question is, does alcohol exposure during this age range alter the lifetime learning ability of individuals?


Source: Science Daily