The Benefits of Sleep
Most people know how much better they feel when they get a good night’s sleep. What they may not realize is that sleep does more than give their bodies and minds a boost of energy; it also repairs them on a cellular level, strengthening the systems that promote health and help fight off diseases and medical conditions. In fact, research is increasingly showing that sleeping well can be as important for your overall health and quality of life as eating a nutritious diet, exercising regularly and not smoking.
Most human beings sleep in cycles of four or five stages. Each cycle lasts 90 minutes to two hours. Sleep scientists have found that the different phases of sleep serve many biological purposes, ranging from memory consolidation to supporting normal immune function and facilitating recovery from injury or disease.
One reason for these complex, varied effects is that sleep is a remarkably adaptive state. Its patterns vary across species but all humans experience a unique kind of rest, characterized by a self-sustaining biorhythm that runs roughly on a 24-hour cycle matching Earth’s day and night. It is driven by a need to rest that grows with the length of time spent awake. Early humans likely consolidated this natural sleep drive into one nocturnal block of sleep to avoid predators and conserve energy while still meeting their need for rest.
During this time, the brain releases hormones and chemicals that support the body’s growth, repair and replenishment. It’s also when the mind is at its most active, with periods of dreaming and other mental activities. Those dreams can help us process emotions, allowing them to be locked into our memories and helping us understand and react to the world around us. That’s why a bad night of sleep can leave us feeling so down and out, and it’s why most people who keep a daily dream journal report that their dreams are more realistic when they sleep well.
Researchers are also finding that REM sleep plays an important role in memory, learning and creativity. A recent study showed that mice deprived of REM sleep had double the amount of amyloid-beta proteins (the toxic protein linked to Alzheimer’s disease) in their brains than those who got plenty of REM sleep. The study’s authors conclude that these findings suggest a potential new way to treat dementia and other neurological disorders by restoring the natural production of cerebrospinal fluid, which occurs during REM sleep and is believed to remove amyloid-beta buildup from the brain.
In general, getting enough high-quality sleep is essential for healthy functioning throughout the lifespan. Poor sleep is associated with a wide range of short- and long-term health problems, including diminished attention and performance, risk for motor vehicle accidents and obesity, high blood pressure, depression and other mood disorders, heart disease, chronic diseases and a greater vulnerability to the common cold.
The best approach to understanding how much sleep you need is to consult with your health care provider. Your provider can run tests, including a sleep study, and may recommend that you keep a diary of your sleep habits to evaluate your current pattern and identify any problems.