Could Too Little Sleep Shrink Gray Matter in the Brain?

Previous studies have linked a lack of sleep or poor quality of sleep to impaired cognitive function as well as an increased risk of other health issues. Now, recent findings published in the journal Neurology show that poor sleep habits can actually cause gray matter to shrink in the brain over time.

"We spend roughly a third of our lives asleep, and sleep has been proposed to be 'the brain's housekeeper,' serving to restore and repair the brain," said lead study author Claire E. Sexton, a postdoctoral, via Health Day. "It may be that greater rates of decline in brain volumes make it more difficult for a person to get a good night's sleep."

For the study, researchers recruited 147 adults from Norway with an average age of 54. The study lasted for three and a half years and involved a series of brain scans. Researchers collected information on the participants sleep quality, weight, level of physical activity and blood pressure.

Researchers found that many needed as much as 20 minutes to fall asleep and slept seven hours each night. They compared the brain scans from initial findings to other accounting factors, such as weight, level of physical activity and blood pressure.

The results revealed that people who reported poor sleep quality had shrinkage in one region of the frontal cortex, as well as deterioration in three other parts of the brain that are linked to reasoning, planning, memory and problem solving. Furthermore, over 35 percent of the participants had met the criteria for poor sleep quality.

However, researchers found that with the link between poor sleep and brain shrinkage, they did not test participants' cognitive skills. Therefore, they could not fully conclude that poor sleep and brain shrinkage might lead to impaired thinking.