DRINKING DURING ADOLESCENCE and early adulthood can slow down brain development, according to researchers who studied alcohol’s effects on monkeys.

The brain undergoes crucial developments as we transition from adolescence to adulthood, right as many people start drinking for the first time.

The authors of fresh research published in the journal eNeuro tried to determine what alcohol does to brains of teens by examining its effects on 71 rhesus macaque monkeys who were given unrestricted access to booze.

The paper found that heavy alcohol use reduced the rate of brain growth by an alarming amount, 0.25 millilitres per year for every gram of alcohol consumed per kilogram of body weight to be exact. This is roughly equivalent to four beers per day.

The strictly controlled experiment saw the scientists precisely measure the monkeys drinking and diet as well as their daily activities. This ruled out other factors that have undermined similar studies involving people.

“Human studies are based on self-reporting of underage drinkers,” one of the study’s authors, Christopher Kroenke, Ph.D., explained. “Our measures pinpoint alcohol drinking with the impaired brain growth.” 

Figures from Alcohol Action Ireland show that 64% of 13 to 17 years olds have tried alcohol and nearly half of those go drinking every month.

Commenting on the potential harm of teenage drinking the study’s lead author, Dr Tatiana Shnitko, said: 

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

The scientists hope their data will spark further research into how brains develop during adolescence and whether drinking during this time makes a person more susceptible to alcohol issues later in life.