June 2020
THE ROLE OF SLEEP IN HEALTH
Why everyone should make sleep a priority
Along with food, water, and oxygen, we cannot live without sleep. Yet one in three Americans reports not getting enough sleep. Deficient shuteye, meaning not enough or low-quality sleep, has been linked to poorer dietary choices, increased risk of chronic diseases, decreased lifespan and reduced psychological well-being, suggesting that sleep should be higher up on everyone’s to do list.
Research suggests that sleep may help remove toxins from the brain that build up during waking hours. Sleep also may help with learning new information, making memories, and regulating emotion. Although sleep patterns change as we age, a full night of sleep consists of cycling through the sleep stages, 1,2,3 and rapid eye movement sleep, or REM. The recommendations are that adults get at least 7 hours of sleep each night. In addition to enough sleep, quality sleep is also important. Indicators of poor sleep quality include frequently waking during the night, not feeling rested after a full night of sleep or episodes of snoring or gasping for air, which may indicate a serious sleep disorder.
A lack of sleep may result in making poor food choices, eating too many calories and a higher risk of being overweight or obese. Not getting enough sleep can lead to an increase in ghrelin, a decrease in leptin, or both. Leptin and ghrelin are hormones that are key in regulating appetite and food intake. In short, an increase in ghrelin means an increase in hunger, and an increase in leptin means satiety, or fullness. Not getting enough sleep may make the brain more sensitive to food stimuli, such as sights and smells, and may make finding food more rewarding. Not getting enough sleep also may increase the brain’s endocannabinoids, increasing hunger and appetite. Additionally, less sleep may alter resting metabolic rate, or the total number of calories burned at rest and needed for basic bodily functions such as breathing. Along with the more complicated hormonal and cerebral theories of why inadequate sleep leads to overeating comes a simpler explanation: Less sleep means more time awake, which means more time to eat.
Some science suggests sleep deprivation can reduce the body’s ability to build up defenses against illness. The immune systems of individuals with healthy sleep were better at “remembering” a virus and had an enhanced ability to attack it, compared to those individuals who did not get enough sleep. This is especially important during this difficult time in our country. Additionally, insufficient sleep can result in increased white blood cell count, indicating inflammation. Not getting enough sleep can increase inflammatory markers, stimulate immune cells and prolong recovery. While stress can interfere with sleep, the reverse is also true: Lack of sleep can increase stress. Deficient sleep can interfere with processing emotions, suggesting that people who do not get enough sleep may be less capable of empathy. People with insomnia and obstructive sleep apnea are more likely to experience depression compared to individuals with healthy sleep. Finally, short sleep duration and long sleep duration are associated with all-cause mortality, meaning too little or too much sleep can increase risk of death. The lowest risk was around 7 hours of sleep per night.
Esther L. Ellis, MS, RD, LDN
For more information about sleep and how it affects your overall well-being, please consult your physician or registered dietitian.