New research is providing more proof of the recuperative power of sleep.
The research, conducted at the University of Pennsylvania and written up in two papers that are to be published in the journal Sleep, used fruit flies to examine how sleep during illness impacts recovery time. While it sounds obvious that sleeping will help you feel better soon, they had some surprising results.
The scientists subjected fruit flies to sleep deprivation before infecting them with a bacteria. Both the sleep-deprived flies and a non-sleep-deprived control group displayed increased sleep after infection, what the experimenters call an “acute sleep response.”
Unexpectedly, however, the flies who were sleep deprived prior to infection actually lived longer after the infection. The Penn team found that prior sleep deprivation made the flies sleep for a longer period after infection as compared to the undisturbed controls. Inducing sleep deprivation after infection rather than before made little difference, as long as the infected flies then got adequate recovery sleep.
“We deprived flies of sleep after infection with the idea that if we blocked this sleep, things would get worse in terms of survival,” explained University of Pennsylvania Center for Sleep and Circadian Neurobiology research associate Julie A. Williams, PhD. “Instead they got better, but not until after they had experienced more sleep.”
In a second study, the researchers manipulated sleep through a genetic approach. Compared to a control group, flies that were induced to sleep more, and for longer periods of time for up to two days before infection, showed substantially greater survival rates. The flies with more sleep also showed faster and more efficient rates of clearing the bacteria from their bodies.
“Again, increased sleep somehow helps to facilitate the immune response by increasing resistance to infection and survival after infection,” notes Williams. “These studies provide new evidence of the direct and functional effects of sleep on immune response and of the underlying mechanisms at work. The take-home message from these papers is that when you get sick, you should sleep as much as you can — we now have the data that supports this idea.”