A good night’s sleep is important to keep you looking and feeling your best the next day, but it also plays a fundamental role in your overall health. Not only does lack of sleep make you feel like a zombie, racing back and forth to the coffee machine the next day, but it also raises your risk of a number of health complications, including heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity, and depression. Now, research has found one more potential health issue that could arise from not getting enough sleep: cognitive decline.
The new study, which was published in the journal Neurology, tracked the sleep of more than 500 people in their late thirties and early forties during two overnight visits about a year apart. Overall, the researchers got data on about six hours of sleep per person. Scientists captured data on sleep quality with the help of a wrist activity monitor that tracked things like how long people slept, how often they moved, and how often they were interrupted during the night.
The researchers followed up with those people more than 10 years later and gave them cognitive tests to check things like processing speed, executive function, and memory. The researchers found that people who had more fragmented sleep, time spent tossing and turning and switching positions in bed, at the start of the study had lower scores on all of the tests. This didn’t affect race or sex as much: People of all genders and races experienced a gap in cognitive scores on the original test when their sleep was fragmented.
The conclusion, according to the researchers: “Sleep quality is important for cognitive health, even as early as midlife.” It’s important to point out that the researchers didn’t definitively find that getting broken-up sleep a decade beforehand caused people to score lower on cognitive tests in the future. But the study did find a link that’s interesting.
This isn’t the only research to connect sleep issues with dementia. A JAMA Neurology study published in October 2023 found that people who chronically lose slow-wave sleep (the third stage of sleep where the brain removes potentially harmful materials and the body catches up on deep, restorative rest) had a higher risk of developing dementia.
Research published in the Journal of Sleep Research in 2021 also found that people who commonly woke up in the night and had trouble getting back to sleep on a nightly basis, depriving them of restorative sleep, had a nearly 40% higher risk of developing dementia.
Here’s the thing: It can be tough at baseline to get the recommended seven to nine hours of sleep a night. And, if you’re dealing with things like work stress, a partner who snores, or hot flashes or night sweats, it can also be difficult to sleep soundly and stay asleep throughout the night.
If you’re having trouble getting consistent sleep, it’s important to take a closer look at your sleep hygiene. According to the Centers for Disease Control and Prevention (CDC), that means doing things like:
Making sure your bedroom is quiet, dark, and at a comfortable temperature
Removing screens, like your phone and computer, from your bedroom
Avoiding large meals, caffeine, and alcohol before you go to bed
Getting regular exercise
But sometimes good sleep hygiene isn’t enough. If curating a more regular, calming wind-down routine each night not helping, talk to your doctor. There are a range of things that could be interfering with your sleep, from perimenopause or menopause to sleep disorders, and many have treatment options. Figuring out what’s behind your fractured sleep and taking steps to solve it can make a big difference in your physical and mental health and well-being, now and in the future.