Yesterday I reported on a new study which concluded that getting too little sleep directly affects one’s risk of catching a cold. Today, I have more for you on the extremely important—but often overlooked—role that sleep plays in overall health. As we saw yesterday, cutting one’s sleep short by just two hours per night can dramatically affect one’s immune system function. Sleep deprivation has also been linked to other negative outcomes, such as slower reaction times, inability to think and make decisions clearly, and a decline in the ability to pay attention—whether it’s in the classroom, or behind the wheel.
Yesterday’s story made it clear that skipping sleep is nothing to be proud of. It clearly takes a toll on overall health. But researchers at Washington State University say there’s more to it than just the number of hours you spend sleeping every 24-hour cycle. It’s also about timing.
Many aspects of modern life compete with our immutable need for regular, restorative sleep. Factors such as extensive artificial lighting at night, shift work, jet lag, and the blue light emitted by our digital devices may all affect a person’s ability to fall asleep on a regular schedule. And that may pose a problem.
Ilia Karatsoreos is an assistant professor in WSU's Department of Integrative Physiology and Neuroscience. He led an experiment in which mice were forced to live on a 20-hour cycle, rather than the usual 24-hour cycle. Although the animals got the same number of hours of sleep, it was of a different, less restorative quality. Just as occurred among humans who slept too little, immune system function suffered. Some mice had sluggish immune responses to an intentionally administered immunity challenge, while others showed overactive responses."This represents a very clear dysregulation of the system," said Karatsoreos. "The system is not responding in the optimal manner.”
"Just like you have a car that you're running into the ground—things don't work right but you keep driving it until it stops. That's what could happen if you think of disruption going on for years for somebody who's working shift work," he said.
Derrick J. Phillips, Marina I. Savenkova, Ilia N. Karatsoreos. Environmental disruption of the circadian clock leads to altered sleep and immune responses in mouse. Brain, Behavior, and Immunity, 2015; 47: 14 DOI: 10.1016/j.bbi.2014.12.008