Too much, too young (Image: Danny Joint/PYMCA/Rex Features)

Post-mortems of binge-drinking adolescent monkeys have produced the best evidence yet that heavy drinking at an early age can do lasting damage to the brain.

The worst damage was to stem cells destined to become neurons in the hippocampus, the brain area responsible for memory and spatial awareness.

Monkey and human brains develop in the same way, so the finding suggests that similar effects may occur in human teenagers. It thus reinforces the rationale for anti-alcohol policies in the US and elsewhere which aim to raise the age at with people start to drink.


Starting young

Chitra Mandyam of the Scripps Research Institute in La Jolla, California, and colleagues gave four rhesus macaque monkeys citrus-flavoured alcoholic drinks for an hour a day over a period of 11 months. Two months later the animals were killed, and their brains were compared with those of monkeys that had not consumed alcohol.

The bingeing monkeys had 50 to 90 per cent fewer stem cells in their hippocampus compared with the controls. “We saw a profound decrease in vital cells,” Mandyam says.

“What is important for the public to know is that this type of drinking can kill off stem cells.” This loss could result in damage to memory and spatial skills, she adds.

Lasting effects

Mandyam thinks that this degeneration could have long-term effects and provide a mechanism for why bingeing teens are more likely to develop alcohol dependence as adults.

A new policy to combat under-age drinking was launched earlier this month by the American Academy of Pediatrics (AAP). It is based on results from earlier studies which showed that 41 per cent of children who start drinking regularly at 12 years of age develop lifelong dependency, compared to 11 per cent of people who start drinking at 18.

“The findings support the US Surgeon General’s efforts to delay drinking initiation among young people,” says Ellen Witt of the US National Institute on Alcohol Abuse and Alcoholism in Bethesda, Maryland. “It’s also important to recognize that binge drinking may produce adverse consequences on the brain regardless of age.”

Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0912810107)