Search Here

Poor sleep quality and sleep deprivation have been linked to impaired cognitive functions the following day. In a new study, researchers examined how sleep quality affected brain health. They discovered that people who consistently did not get a good night's sleep had shrinkage in their brain's gray matter 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 researcher Claire E. Sexton, a postdoctoral research assistant at the University of Oxford in England reported by Philly. "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,"

Sexton conducted this study when she was a visiting research fellow at the University of Oslo. She and her colleagues recruited 147 adults from Norway with an average age of 54 at the beginning of the study. The study lasted three and a half years and involved a series of brain scans.

During the second scan, the participants had to complete questionnaires that collected information on their sleep quality, which included how long they sleep, how well they slept, how long it took them to fall sleep, how much time was spent awake in bed, how often they woke up, level of sleepiness during the day and the use of any sleeping medications. On average, people needed 20 minutes to fall asleep and slept seven hours each night.

The researchers compared the brain scans after accounting for factors, such as weight, level of physical activity and blood pressure. They found that people who reported poor sleep quality had shrinkage in one region of their frontal cortex. They also had deterioration in three other parts of the brain that are linked to reasoning, planning, memory and problem solving. Overall, 35 percent of the participants had met the criteria for poor sleep quality.

"We often correlate brain shrinkage with losing brain tissue, and assume that that isn't advantageous as you get older," said Anton Porsteinsson, director of Alzheimer's disease care, research and education at the University of Rochester School of Medicine and Dentistry in New York. "Sleep disturbance is such a common symptom among the general population, and it often becomes worse as you age. There is growing data to suggest that sleep disturbance may be a risk factor for poor outcomes in terms of brain cells and other medical issues as well."

Despite finding a link between poor sleep and brain shrinkage, the team did not test the participants' cognitive skills and therefore, could not conclude that poor sleep and brain shrinkage impaired thinking skills. Regardless, the researchers recommended people with sleeping problems to seek help. Poor sleep quality could be due to several factors, ranging from a bad mattress to stress levels. In order to improve sleep, people have to identify the problems and address them.

"It is not yet known whether poor sleep quality is a cause or consequence of changes in brain structure," said Sexton reported in the press release. "There are effective treatments for sleep problems, so future research needs to test whether improving people's quality of sleep could slow the rate of brain volume loss. If that is the case, improving people's sleep habits could be an important way to improve brain health."

The study, "Poor sleep quality is associated with increased cortical atrophy in community-dwelling adults," was published in the journal Neurology.