Most of us intuitively know that sleep is good for us. If you have a night without good rest, you’ll feel lethargic. String a few nights of poor sleep together and you’ll feel down right terrible. Conversely, we know that feeling of waking up refreshed and ready to take on the world!
Although we spend over 25% of our lives doing it, humans are still not entirely sure WHY we sleep. Research over the years has concluded that sleep plays a critical role in many vital functions, including:
Immune Function: It is natural for people to go to bed when sick. Substances produced by the immune system to fight infection also cause fatigue. One theory suggests the immune system evolved “sleepiness inducing factors” because inactivity and sleep provided an advantage: those who slept more when faced with an infection were better able to fight that infection than those who slept less. In fact, research in animals suggests that animals who obtain more deep sleep following microbial infection have a better chance of survival.
Metabolism and Weight Control: During sleep, our bodies secrete hormones that help to control appetite, energy metabolism, and glucose processing. Getting too little sleep upsets the balance of these and other hormones. Poor sleep leads to an increase in cortisol, often referred to as the “stress hormone.” It is also associated with increases in the secretion of insulin following a meal. Insulin regulates glucose processing and promotes fat storage. Higher levels of insulin are associated with weight gain, a risk factor for diabetes. Insufficient sleep is also associated with lower levels of leptin, a hormone that alerts the brain that it has enough food, as well as higher levels of ghrelin, a biochemical that stimulates appetite. As a result, poor sleep may result in food cravings even after we have eaten an adequate number of calories.
Memory: Researchers hypothesize that slow-wave sleep (SWS), which is deep, restorative sleep, also plays a significant role in declarative memory by processing and consolidating newly acquired information. Studies of the connection between sleep and declarative memory have had mixed results, so this is an area of continued research.
Learning: When we are sleep deprived, our focus and attention suffer, making it difficult to process new information. If our brains and neurons are not adequately rested, neurological function suffers, and we lose the ability to access previously learned information.
CONSEQUENCES OF INADEQUATE SLEEP
In today’s world, we are constantly trading sleep for just a few more hours of work or play. Science is just starting to understand the importance of sleep on one’s overall health. In the short term, inadequate sleep affects judgement, mood, ability to learn and retain information, and increases the risk of serious accident or injury. In the long term, chronic sleep deprivation can lead to a host of health problems including Obesity, Heart Disease, Diabetes, and Mental Health issues.
Quality sleep is critical to a healthy and happy lifestyle! If you think you might suffer from a sleep disorder, speak with your physician. You do not need to live your life on poor rest!