Drinking excessively during the adolescent and youthful years, on the threshold of adulthood, not only carries the risks of all known, but can also significantly reduce the level of brain growth .
This has been revealed by an investigation carried out with non-human primates, the results of which have been published in the journal eNeuro . Specifically, it has been shown that excessive alcohol consumption reduces the rate of brain growth by 0.25 milliliters per year for each gram of alcohol consumed per kilogram of body weight . In human terms, that amount is equivalent to having four beers per day .
The research, led by Christopher Kroenke and Tatiana Shnitko of the Oregon National Primate Research Center in the United States, was carried out with young rhesus macaques. As the authors write in the study, ” chronic alcohol intoxication slowed the growth rate of the brain, cerebral white matter, and the subcortical thalamus .”
To verify this, they measured the growth of the organ by analyzing magnetic resonance images of 71 rhesus macaques that had consumed ethanol or alcoholic beverages. The scientists precisely measured the dose ingested, the diet they followed, the daily schedules and the medical attention, to rule out other factors that could lead to confound the results in studies with humans. The research findings help support earlier work on the effects of alcohol use on brain development in people.
“The human studies are based on personal reports from underage drinkers,” says one of the authors of this research Christopher Kroenke, associate professor in the Division of Neuroscience at the primate center. “Our measurements link alcohol consumption with impaired brain growth, ” he adds.
The new study stipulated that normal brain growth is one milliliter per 1.87 years in rhesus macaques in late adolescence and early adulthood. And it also revealed a decrease in the volume of different areas of the brain due to the voluntary consumption of ethanol.
The lead author of the research, Tatiana Shnitko, a research assistant professor in the Division of Neurosciences at the primate center, explains that previous research has shown that the brain has the ability to recover, at least in part, after cessation of alcohol intake, but it is not clear whether there will be long-term effects on mental functions when the adolescent and adult brain finish their growth phase.
The next stage of the investigation will explore that question. “This is the age range in which the brain is being refined and sophisticated to adapt to the responsibilities of adults – says Shnitko -. The question is whether exposure to alcohol during this age range alters the ability to learning about people’s lives “.
