Why Feeling Sleepy During the Day Could Mean Trouble for Your Brain

Updated: Sep. 21, 2018

If you’re always sleepy during the day, it might mean problems for your brain down the line

dizzinessSFIO CRACHO/Shutterstock

If you’re sleep deprived, it can present itself in many ways, such as constantly dozing off at the office or napping more than a cat. A quick fix for sleep deprivation could be as simple as establishing a healthy bedtime routine consisting of seven to eight hours of shut-eye each night. Or a doctor’s visit could help diagnose and resolve the problem if your excessive daytime sleepiness persists. Either way, the sooner you fix your sleeping issues, the better, because a consistently sleepy body may spell trouble for your brain down the line. Find out the 15 habits you probably don’t know are aging your brain.

Researchers from Johns Hopkins University found that people who reported feeling sleepy throughout the day were nearly three times more likely than people who didn’t experience sleepiness to have a buildup of beta-amyloid—a protein that’s associated with a higher risk of Alzheimer’s disease—years later.  The researchers analyzed data from the Baltimore Longitudinal Study of Aging, a long-term study that’s been following the health of thousands of volunteers since 1958. Throughout the years, volunteers filled out periodic surveys that included questions about how often they napped, felt drowsy, or fell asleep during the day. Some of the participants also received brain scans that detected beta-amyloid plaques in the brain tissue nearly 16 years after they filled out the surveys.

The research team found 123 volunteers who answered the questions and got their brains scanned. After researchers adjusted for sex, age, education, and body mass index, the results showed that the risk for beta-amyloid plaques was 2.75 times higher for people who felt sleepy during the day. The risk for this plaque buildup in people who took naps was not nearly as statistically significant. Try these 11 tips for taking a nap that energizes you.

The correlation between daytime sleepiness and increased risk for beta-amyloid plaques continues to baffle scientists. One likely explanation is that sleep disturbances and/or sleep deprivation not only can make a person feel extremely sleepy but may also cause beta-amyloid plaques to form through an unknown mechanism. “However, we cannot rule out that amyloid plaques that were present at the time of sleep assessment caused the sleepiness,” lead author Adam P. Spira, PhD, associate professor in the department of mental health at the Johns Hopkins Bloomberg School of Public Health, said in a press release.

In the medical field, it’s well-known that sleep disturbances are common in people who have Alzheimer’s disease because the associated brain changes can negatively affect their sleep. But many studies in both animals and humans have also linked poor sleep with greater numbers of beta-amyloid deposits in the brain. This new study adds to the growing body of evidence that sleep quality could be a risk factor that can be easily modified. “There is no cure yet for Alzheimer’s disease, so we have to do our best to prevent it,” says Spira. “Prioritizing sleep may be one way to help prevent or perhaps slow down this condition.” Next, check out what your sleeping habits are trying to tell you.