Our New Year’s Resolution is to help you sleep better. Our four part series on the science of sleep, posted every Sunday in January, focuses on a subset of sleep and its importance.
How Sleep Heals Us: Mind, Body, and Mood
Sleep is not one constant state; it’s made up of several distinct stages totaling between 90-120 minutes. We cycle through one round of these stages four to five times a night, going from light-sleep, to deep slow-wave sleep, to dream-producing rapid eye movement (REM) sleep.
During the first half of the night, we spend more time in slow-wave sleep, which is vital to immune function and body repair. Dr. Mullington, an Associate Professor of Neurology at the Division of Sleep Medicine at Harvard Medical School reports that the highest level of human growth hormone (HGH) is produced during this stage. This hormone fuels growth in children and helps maintain tissues and organs throughout life.
White blood cells, the body’s infection fighters, ramp up their circulation, too, during this stage. Studies published in the Journal of Sleep found that subjects who typically slept more than seven hours a night were more likely to develop immunity to hepatitis B after vaccination, than were those who clocked less than that amount.
A study published in the Archives of Internal Medicine found that participants who slept less than seven hours a night were nearly three times more likely to develop a cold when exposed to a virus than were those who enjoyed eight hours or more of shut eye.
What’s the reason, you ask? One possible reason is that sleep deprivation is thought to reduce the natural cells that can help ward off infection. Insufficient sleep has also been linked to greater risks for all kinds of health problems — heart attacks, strokes, diabetes, and inflammation.
So, how can you max out your time spent healing? Make your sleeping environment as dark as possible. Reports show that countries that generate the most artificial light at night, such as the United States, also have the highest incidence of breast cancer. Researchers theorize that light makes your brain think that it must be morning, therefore throwing off your circadian rhythms and robbing you of the most healing portions of sleep.
Regardless of your goals for the new year — they should include getting a more restful night’s sleep as often as possible. Sleep well, sleep wicked.