Brain Featured Research

Study examines how sleep may help brain immune cells stay “young”

A woman sleeps behind a clock that strikes 7:00 a.m.
Written by Jennifer Palisoc

In the first study to examine the impact of poor sleep on the brain’s immune cells, researchers found that chronic sleep loss may prematurely age the brain’s immune cells, which may lead to problems with thinking, memory and possibly dementia later in life.

“Our study showed that older adults who sleep poorly have premature aging and abnormal activation of the brain’s immune cells,” says Dr. Andrew Lim, principal investigator of the study and sleep neurologist at Sunnybrook Health Sciences Centre.

The study, “Sleep fragmentation, microglial aging, and cognitive impairment in adults with and without Alzheimer’s dementia,” has been published in the journal, Sciences Advances.

Dr. Lim explains immune cells of the brain are called “microglia,” which can protect the brain and “eat” pathogens and debris. When these cells are “activated” they can cause a number of concerns.

“Chronically losing sleep may cause inflammation of the brain and cause it to age faster,” says lead author, Kirusanthy Kaneshwaran, a third year medical student at the University of Toronto, who worked with Lim on this study. “This was detected through actual, identifiable changes in the inflammatory cells of the brain.”

“Those in the study who had better sleep had “younger” and less activated brain immune cells, and this was relatively protective against the negative effects of Alzheimer’s disease pathology on cognition,” says Dr. Lim.

“I hope this research helps further understanding of the mechanism underlying problems with memory and cognition, and awareness of the important role of sleep,” says Kaneshwaran.

Tips for older adults to help improve their sleep

  1. Don’t simply accept poor sleep as being a part of normal aging – if you are having trouble falling or staying asleep, or if you are excessively sleepy during the day, bring this up with your doctor!
  2. Keep regular sleep hours, and a regular nighttime routine, and wake-up schedule, that feels right for your body.
  3. Get up at the same time every morning no matter how much sleep you got during the night. Maintaining a routine can help improve sleep.
  4. Speak with you doctor about ways to maximize physical activity.
  5. Try to maximize exposure to natural light during the day.
  6. Limit caffeinated foods and beverages, such as coffee, tea, soft drinks, and chocolate.
  7. Limit use of alcohol.

“This study provides another reason for older adults to sleep well, and to have sleep problems looked after,” says Dr. Lim. “Sleeping well may prevent premature aging of the brain’s immune cells and by doing so, may prevent impaired cognition.”

In-depth – learn more about the study: Sleep fragmentation, microglial aging, and cognitive impairment in adults with and without Alzheimer’s dementia, has been published in the journal, Sciences Advances.

About the author


Jennifer Palisoc

Jennifer Palisoc is a Communications Advisor at Sunnybrook.

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