We’re all familiar with this restorative role of sleep for the brain–pulling an all-nighter or staying awake during a red-eye flight can not only change our mood but also affect our ability to think clearly until, at some point, it practically shuts down on its own. When we don’t get enough sleep, we’re simply not ourselves.
In the past five years, brain researchers have begun to expose a hidden world of chemical reactions, fluids flowing into and out of the brain, and the busy work of neurons that reveal the sleeping brain is as industrious as the waking one. Without good-quality sleep, those critical activities don’t take place, and as a consequence, we don’t just feel tired and cranky, but the processes that lead to certain diseases may even get seeded. One of the reasons we sleep, it now seems, might be to keep a range of illnesses–including cognitive diseases like Alzheimer’s and other dementias–at bay.
In part that’s because while medical experts have long recommended seven to eight hours of sleep a night–including some time spent in deep, or non-REM, sleep–exactly what our bodies are doing during that time is less clear. Now, thanks to newer technologies for measuring and tracking brain activity, scientists have defined the biological processes that occur during good-quality sleep. That they seem to be essential for lowering the risk of brain disorders, from the forgetfulness of senior moments to the more serious memory loss and cognitive decline of dementia and Alzheimer’s disease, may convince the world that sleep is not for the lazy.
“Evidence like this suggests that those of us who want to be healthy for longer should be doubling down on sleep as a priority because it really keeps the brain and the whole neurological system as optimal as a can be. We know more and more and more about how awesome sleep is for staying healthier longer,” Adam says.
To find out more, researchers are studying people with disorders like sleep apnea, or those who work night shifts or keep irregular working hours, such as first responders, pilots and flight attendants. Studies already suggest that all of these groups are more vulnerable to Alzheimer’s. The next step is to see if treatment, or changes in sleep habits, matters. In shift workers, researchers want to test the impact of resetting their biological clocks to a standard day-night schedule. If these efforts lower their likelihood of developing Alzheimer’s, that would make a strong case for a connection between lifelong sleep patterns and risk of dementia.
Adam stresses that “it's important to acknowledge that people who work shift work don't usually have control over their work hours. But having said that, we all have a choice about how big a priority we make sleep.”