This blog rotates through 13 themes each quarter of the year. Thirteen weeks ago we discussed sunshine, the natural source of vitamin D. Vitamin D from sunshine is reported to last twice as long in our body as vitamin D from pills—so it seems there is a physiological difference with sunshine that may be beneficial. The full spectrum light from sunshine was addressed last year in the post, Let There Be Light.
This time we address the opposite theme—the importance of time in the dark, sleeping. I’m surprised how often we find guidance on how to live by the Creation account in Genesis:
“And God said, ‘Let there be light; and there was light. And God saw that the light was good; and God divided the light from the darkness. And the evening and the morning were the first day.” (Genesis 1:3,4)
The division of light from darkness was important, I believe, but in our time, with electric lighting, true darkness has been much reduced and the division compromised.
Melatonin is the master hormone of the night, a blessing of adequate sleep. When we close our eyes in a darkened room the pineal gland, a sort of third eye, is triggered by darkness to produce melatonin. The production of melatonin peaks in the fourth hour of sleep, which then produces other beneficial hormones that restore and prepare us for the coming day. Basically, you make melatonin for 4 hours; the other hormones do their work the next 4 hours. (In infants, melatonin production stabilizes in the 3rd month, enabling them to sleep through the night, at last.)
Melatonin is also a potent antioxidant, a protection for your DNA. Though our understanding of melatonin is incomplete, it seems important to health to not shortchange the body through insufficient sleep, in a darkened room. The division of dark from light in the Creation is important today also.
Scientists have linked some chronic diseases to insufficient sleep, as discussed in the post, Blessed Sleep. These include depression, hypertension, type 2 diabetes and overweight, heart disease and cancer. There are also mental effects including dementia and impaired judgment.
I connect the growing dependence of stimulants like caffeine and sugary drinks in the last century to our decline of adequate sleep in a darkened room. If sleep is not fully refreshing we crave stimulants to get going, more than nutrients. A sugary breakfast cereal, a mid-morning soft drink, and candy snacks during the day will seem the right answer. If you get adequate sleep, 8-9 hours per night, you’ll need less sugar and this will lower your insulin level thus allowing your body to release and consume fat for energy. When insulin is high, sugar is stored as fat; when it’s low, fat is released for consumption.
A 2010 University of Chicago study of dieters found that those who got the most sleep lost twice as much fat as those with the least sleep (8.5 Hrs. vs. 5.5 Hrs.). As excess fat is a widespread problem in America, adequate sleep in the dark may be the cheapest health aid available. A prior post, The Skinny On Overweight, argued that rather than the pain of repeated dieting, it would be better to first try eating a wholesome diet combined with exercise.
Please comment: Are you able to get adequate sleep? How much do you need? Have you experienced sleep-related health issues? Do you eat better if your sleep better? What did you do to improve your sleep habits.