A study at Oregon National Primate Research Center, USA, shows that heavy alcohol use can slow the rate of brain growth.
The study, published in the journal eNeuro, shows that heavy alcohol use reduced the rate of brain growth by 0.25 millilitres per year for every gram of alcohol consumed per kilogram of body weight. In human terms, that’s the equivalent of four beers per day. The research involved rhesus macaque monkeys at the Oregon National Primate Research Center.
What’s the link between brain growth and heavy alcohol use?
“Chronic alcohol self-intoxication reduced the growth rate of brain, cerebral white matter and subcortical thalamus,” the researchers write.
Researchers measured brain growth through magnetic resonance imaging of 71 rhesus macaques that consumed ethanol or beverage alcohol.
The scientists precisely measured intake, diet, daily schedules and health care, thus ruling out other factors that tend to confound results in observational studies involving people.
The findings in the study help validate previous research examining the effect of alcohol use on brain development in people.
“Human studies are based on self-reporting of underage drinkers,” said co-author Christopher Kroenke, Ph.D., an associate professor in the Division of Neuroscience at the primate center. “Our measures pinpoint alcohol drinking with the impaired brain growth.”
The new study is the first to characterise normal brain growth of 1 millilitre per 1.87 years in rhesus macaques in late adolescence and early adulthood. And it also reveals a decrease in the volume of distinct brain areas due to consumption of ethanol.
Delving further into brain growth
Lead author Tatiana Shnitko, Ph.D., a research assistant professor in the Division of Neuroscience at the primate centre, explained how previous research has shown the brain has a capacity to recover at least in part following the cessation of alcohol intake.
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, or the fact that excessive alcohol consumption could lead to chronic diseases. The next stage of research will further explore that question.
“This is the age range when the brain is being fine-tuned to fit adult responsibilities,” Shnitko adds.
“The question is, does alcohol exposure during this age range alter the lifetime learning ability of individuals?”