Health. Sleep impacts the cognitive abilities of the adolescent brain

The future belongs to those who get up early. As long as they don't go to bed too late. This is what a study on adolescent sleep reveals. Those who get the longest night's sleep perform better on cognitive tests than their peers who sleep less.

Cognitive data from 3,200 young people was analyzed by a team of researchers from Fudan University in Shanghai. Each of them's sleep was analyzed to understand the impact of sleep on intellectual development.

And the results are clear: a teenager who sleeps an average of 8 to 10 hours a night has a better-developed and more responsive brain than another who sleeps about 7 hours every night. The former also display a lower heart rate during their lethargy.

A decrease in gray matter

"As this study shows, going to sleep late and sleeping less is problematic. There's no doubt this problem is exacerbated on school days, when young people have to get up relatively early for school and catch up on weekends - a phenomenon known as social jet lag," says Colin Espie, a professor and sleep expert at the University of Oxford, in a Guardian article.

In 2017, an Inserm study demonstrated that a night of sleep of less than 7 hours during the week was linked to a decrease in the volume of gray matter in certain regions of the brain. "The most significant result of our study is certainly the one showing that the later adolescents go to bed on weekends, the more their gray matter volume is reduced," emphasized Jean Luc Martinot, research director at Inserm.

It is recommended to exercise regularly and avoid looking at screens before going to sleep to promote the secretion of melatonin in our brain. This hormone helps us fall asleep.