The science of sleep is a relatively new area of research, but there have been several alarming discoveries about the effects of sleep deprivation in recent years. In May, researchers publishing in the journal Nature Reviews Neuroscience found that sleep deprivation can severely impact memory function and learning ability. But people who don’t get enough sleep are putting themselves at risk for a lot more than forgetfulness.
“Getting less than 7 hours of sleep per night on average reduces lifespan,” Adam Krause, co-author of the study and a graduate student at the University of California, Berkeley, told Seeker. “Short-sleepers tend to be less active, and overweight [and] they have higher rates of cardiovascular and metabolic diseases, such as high blood pressure, and diabetes.
Sleep deprivation is also associated with weight gain and obesity. A 2016 report showed that people who were sleep deprived reported an increase in hunger and were more likely to choose unhealthy foods to snack on. The researchers found that when people didn’t get enough sleep, their endocannabinoid system was activated — the same system activated by the chemicals in marijuana. Essentially, being tired makes it a lot harder to avoid junk food cravings.
“Sleep really is a pillar of health, along with eating well and exercising,” Kate Sprecher, a postdoctoral associate in the sleep and chronobiology laboratory at the University of Colorado, Boulder, said. “Not sleeping enough is not something to be proud of, just like smoking is not something you would brag about.”
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Sprecher points out that getting enough sleep is crucial not only for physical health but mental health as well.
“Insufficient sleep results in worse mental performance. People make more mistakes, which leads to decreased productivity as well as safety issues,” Sprecher said. “Drowsy driving causes many car crashes, and some well-known safety failures as a result of insufficient sleep include the Chernobyl incident and the Exxon Valdez oil spill.”
Earlier this year, Sprecher led a study, published in the journal Neurology, which found people who reported having poor sleep had greater levels of amyloid beta and Tau proteins in their brain, which are associated with the development of Alzheimer’s disease. Other research has found similar conclusions, including one study showing that even a single night of lost sleep can increase the presence of these proteins in the brain.
The link between sleep deprivation and Alzheimer’s is an emerging area of research, with the disease now affects more than 5.5 million Americans, according to the Alzheimer's Foundation, which funds research.
Sprecher points out that lack of sleep and dementia pathology likely have an interdependent relationship. “We cannot say for sure whether poor sleep causes Alzheimer’s pathology, or whether Alzheimer’s pathology impairs the ability to get good sleep,” Sprecher said. “Based on other research in the field it is likely that both are affecting each other through multiple pathways, but more research is needed to confirm this.”
About 35 percent of people globally report feeling like they don’t get enough sleep, and insomnia affects between 30-45 percent of the adult population, according to a report by the World Association of Sleep Medicine.
To pinpoint a major cause for such widespread sleep deprivation, you need only look to the device you’re reading this on. “The blue light from screens can make you feel more awake and can also shift your circadian rhythm,” Sprecher said, “[which] is like moving yourself to a new time zone.”
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Drinking too much caffeine during the day or too much alcohol before bed are also sleep disruptors, as are stress and anxiety. But one of the biggest reasons most of us fail to get enough sleep, especially workaholic, success-oriented cultures like the US and Japan, is because we tend to think of it as a lazy activity, rather than a productive one.
“Sleep is not at all a passive activity,” Krause of UC Berkeley said. “Your brain is working to prepare you for future learning of new information and efficient recall of memories. During sleep, waste in the brain is removed.”
Both Krause and Sprecher agree that prioritizing sleep is necessary for good health and that one of the best ways to do that is going to bed and waking up at the same time every day. “Keeping a regular schedule is a good way to help you fit sleep into your life,” Sprecher said. Krause says that this regularity, “allows your body to create strong, predictable biorhythms, which can make it much easier to go to bed and get up in the morning.”
The more we discover about sleep, the more we realize just how connected it is to the way our body functions.
“Sleep is a powerful and relatively easy method to improve health,” Krause said. “If you improve sleep just a little, you can observe positive changes in the function of multiple systems.”
WATCH: What Sleep Deprivation Does to Your Body