How sleep deprivation can cause inflammation
Sleep deprivation is what happens when you do not get enough sleep, or enough good-quality sleep. Beyond its effects on mood, memory, and energy, it can also feed inflammation.
Studies have linked sleep deprivation to markers of inflammation, including rises in inflammatory molecules such as cytokines, interleukin-6, and C-reactive protein, a marker that runs high in people at risk for heart disease and diabetes.
Stress, smoking, or obesity could account for some of these signs, but they still point to a role for sleep loss in the inflammatory process. Inflammation is the body's natural, usually temporary response to disease and injury, and it works well as a defense. When it fails to switch off, however, it can contribute to heart disease, diabetes, stroke, cancer, and Alzheimer's disease.
The link between poor sleep and inflammation markers may help explain why people who sleep badly face higher risk of cardiovascular disease, high blood pressure, diabetes, and other chronic conditions.
How might missing sleep drive inflammation? One theory centers on blood vessels. Blood pressure normally drops and blood vessels relax during sleep. When sleep is cut short, that nightly dip does not happen as it should, which may set off cells in blood vessel walls that switch inflammation on. Too little sleep might also disrupt the body's stress response system.
A sleep shortfall also interferes with the brain's housecleaning system, known as the glymphatic system (not the lymphatic system found elsewhere in the body). During the deepest sleep phases, cerebrospinal fluid flows through the brain and sweeps away beta-amyloid, a protein tied to brain cell damage. Without a good night's sleep, this cleaning runs less thoroughly, so the protein builds up and inflammation follows.
Then a vicious cycle begins. Beta-amyloid accumulating in the brain's frontal lobe starts to impair the deeper, non-REM slow-wave sleep, and that damage makes it harder both to sleep and to hold on to and consolidate memories.
Even a single night of lost sleep can leave beta-amyloid levels higher than usual. The real problem is not one bad night, which you can make up for, but a cumulative pattern of sleep loss. Over time that pattern is tied to declines in the structural integrity, size, and function of regions such as the thalamus and hippocampus, which are especially vulnerable early in Alzheimer's disease.
