Researchers at Duke-NUS (Singapore Medical School) concluded that the less adults sleep, the faster their brains age.
They wanted to study the enlargement of the cerebral ventricle. Rapid enlargement of the ventricle is a marker of cognitive decline and the development of neurodegenerative diseases, such as Alzheimer's disease, but the effects of sleep on this marker have never been measured.
The study analyzed data from 66 older Chinese adults. Participants underwent structural brain MRI scans to measure their brain volume and neuropsychological assessments to test their cognitive function every two years. In addition, the sleep duration of each was recorded through a questionnaire.
Those who slept less hours showed evidence of a rapid increase in the ventricle, and consequently a decline in cognitive performance.
"Our results relate short sleep as a marker of brain aging," said Dr. June Lo, lead author of the research.
Sleeping badly is definitely not a good deal. Other studies have shown that lack of sleep in childhood can delay puberty and that sleep is essential to fix our memory (and thereby consolidate learning). In addition, bad nights sleep lead us to eat more and make our mood worse. Now, we also know that sleeping well can help keep the brain healthy.
"The work done suggests that about seven hours (of sleep) per day for adults seems to be ideal for optimal cognitive performance. In the coming years, we hope to determine what is good for long-term cardiometabolic health as well, "added Professor Michael Chee, who also participated in the study.