Most of us might think we can do without sleep – or at least that we can adapt to having less of it. Our 24/7 society seems to demand more of us, with round-the-clock business and entertainment. A single night spent out on the town or surfing the internet may not be detrimental, but added up over time, the consequences of being sleep deprived are numerous and detrimental…while the benefits of sleep can be the difference in health, performance, and quality of life.
Though sleep is typically viewed as a time the body shuts down and rests, according to the National Sleep Foundation, it is actually a dynamic activity in its own right that is as essential to good health as diet and exercise, and as necessary as food and water. Insufficient sleep is directly linked to poor health. Research suggests that insufficient sleep increases the risk for weight gain and obesity; diabetes; high blood pressure; heart disease; stroke; depression, anxiety, and other mood disorders; decreased nervous system performance; decreased endocrine system performance; decreased immune system performance; and premature death. Insufficient sleep contributes significantly to safety issues, such as driving accidents, medical errors, and impaired job performance, which can result in accidents and injuries. Insufficient sleep affects virtually every aspect of day-to-day life, including mood, mental alertness, memory, cognitive performance, energy level, and physical performance.
As we sleep, the brain and body work toward restoration of both the brain and body, while keeping our body chemicals (e.g., hormones, neurotransmitters, etc.) in balance. We sleep in cycles of non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, alternating between the two throughout the night. Although there is still much to be learned about what happens as we sleep, during NREM sleep we know that growth hormones are released, which stimulate tissue growth and muscle repair. There are also increased blood levels of substances that activate the immune system, raising the possibility that sleep helps to defend the body against infection. During REM sleep, it seems that the mind is restored in part by clearing out irrelevant information, but it also facilitates learning and memory. This may be why students who get a good night’s sleep (with uninterrupted REM sleep) fare better than students who stay up all night studying.
Because our bodies are designed to regulate blood pressure, body temperature, and the release of hormones in the appropriate amounts and at the appropriate times, when we go without sleep, this balance can be interrupted, resulting in negative health consequences. In addition to affecting our immune system, sleep deprivation also puts us at risk for:
· Weight gain and obesity – With sleep deprivation, there is an increase in the hormones responsible for the feelings of hunger and a decrease in the hormones that suppress hunger.
· High blood pressure and heart disease – Blood pressure usually falls during the sleep cycle; however, interrupted sleep can adversely affect this normal decline, leading to hypertension and cardiovascular problems.
· Diabetes – Insufficient sleep also impairs the body’s ability to use insulin, which can lead to the onset of diabetes.
According to the National Sleep Foundation, more and more scientific studies are showing correlations between poor and insufficient sleep and disease. The one-third of our lives that we spend sleeping – far from being unproductive – plays a direct role in how full, energetic, and successful the other two-thirds of our lives can be. If sleep is cut short, the body doesn’t have time to complete all of the phases needed for muscle repair, memory consolidation, and release of hormones regulating growth and appetite. Then we wake up less prepared to concentrate, make decisions, or engage fully in school, work, social, and relational activities.
Written by Janet M. Pollard, MPH, AgriLife Extension Associate - Health, Texas AgriLife Extension Service, Texas A&M System.