Sleep deprivation is dangerous, and the effects go far beyond fatigue. A reduced number of hours of sleep, intentionally or not, has deleterious effects on your whole body. Michael S. Jaffee, from the Department of Neurology at the University of Florida, reviews some of the points.
Sleep deprivation has become a major health problem in modern societies. We may be deprived of sleep because of lifestyle or sleep disorders, such as insomnia, obstructive sleep apnea and neurological disorders. But what are the consequences for our physical and mental health?
In addition to severe fatigue, mood disorders, and much longer reaction times, recent studies have shown that adults who sleep less than seven hours a day are more likely to report 10 chronic health conditions, including heart disease, diabetes, obesity, asthma and depression, compared to those who sleep seven hours or more in a 24-hour period. Children are also affected.
The American Academy of Sleep Medicine recommends that children 6 to 12 years sleep 9 to 12 hours a day and adolescents 13 to 18 years of age sleep regularly from 8 to 10 hours a day to promote optimal health. The researchers also found that a single hour of sleep deprivation can have a detrimental effect on the developing brain of a child. A lack of sleep can indeed harm the synaptic plasticity and the encoding of memory; this results in inattention in the classroom.
Each of our biological systems is affected by sleep. By not sleeping enough, you will develop a greater propensity for increased blood pressure and a possible risk of coronary heart disease. Our endocrine system also releases more cortisol, a stress hormone. The body becomes less glucose-tolerant and more resistant to insulin, which in the long run may result in an increased risk of developing type 2 diabetes. In addition, sleep deprivation causes a reduction in growth hormone and muscle maintenance.
We also rely on sleep to maintain our metabolism. Sleep deprivation may result in decreased release of the hormone leptin and increased release of the hormone ghrelin, which may be associated with increased appetite and weight gain. The human body also relies on sleep to maintain our immune system. Sleep deprivation is associated with increased inflammation, decreased antibodies against influenza, and decreased resistance to infection.
There is also a system in our brains that can eliminate potentially dangerous proteins such as abnormal amyloid variants. This waste elimination process relies on sleep to effectively remove these proteins from the brain. These are the same proteins that are present in large amounts in patients with Alzheimer’s disease.