Mar 11
15
The sleep vitamin
Lack of sleep is profound in the changes we have in mood, motivation and vitality, especially for women over 50. It is a major contributor to depression and a sense of “life is not worth living”. It also increases the probability that you will become obese or develop diabetes.
William C. Dement is the world’s leading authority on sleep and founder and director of the Stanford Sleep Research Center. He writes, “Generally people need to sleep one hour for every two hours awake, which means that most of us need around eight hours of sleep a night.” He also goes on to say “the brain keeps an exact accounting of how much it is owed…..we discovered that the effect of each successive night of partial sleep loss carried over, and the effect appeared to accumulate in a precisely additive fashion.” The larger sleep debt we accumulate, the more it tends to impair our overall functioning.
We would sleep all the time if we did not have an arousal mechanism buried within the brain. The most powerful factors that influence alerting are the clock and light. The body likes to fall into a rhythm of waking at a particular time. A powerful influence on setting the time of alerting signals is intense light. Thomas Edison developed the electric light bulb in 1879. Prior to this time the sleep cycles were set by the rising and setting of the sun.
Edison changed all that. We now stay up much later than previous generations. It has been estimated that average sleep has decreased from 8-9 hours in the 1960’s to an average of about 6.9-7 hours in 2000. Sleep time is often spent watching TV or sitting in front of a computer
Since our alerting signal is triggered by light it is undesirable to be exposed to light at night. Red night lights are the least likely to trigger hormone alterations. Red light does not trigger the wake up center in the brain.
Light does not allow the gradual production of melatonin that allows the body to “prepare” for sleep. Watching TV or being on the computer before bed is not a “sleep trigger but an “awake trigger” for the brain. It is best to have a “down” time before turning out the light such as reading a relaxing or inspirational book or a hot bath.
Sleep has a profound effect upon appetite and blood sugar. Eve Van Cauter published a study in 2005 demonstrating that sleep deprivation reduced thyroid stimulating hormone by 30%. Growth hormone which has an anti-insulin action split from one pulse to two pulses with 4 hours of sleep a night.
The other two hormones affected by sleep deprivation are leptin and ghrelin. Leptin is a hormone released by fat cells that suppresses appetite and tells us we are full and satisfied. After 6 days of only 4 hours of sleep at night leptin levels dropped signaling famine even thought subjects were well fed.
Ghrelin is a hormone which stimulates appetite, particularly for high-carbohydrate foods. Sleep deprivation causes significant increases in ghrelin. Ghrelin levels rose between 15% and 28% in different sleep deprivation studies.
In another study were the subjects only sleep 4 hours a night for 6 night’s lack of sleep created insulin resistance. Blood sugar levels of the sleep deprived subjects were higher after breakfast despite the fact that their insulin levels were normal or elevated.
The ability to clear glucose from the blood stream slowed by 40% among the sleep volunteers and insulin response to glucose fell by 30%. Fortunately all measures were restored to normal after “repaying” the sleep debt by sleeping 12 hours a night for a number of nights.
William C. Dement writes, “We can state with confidence that if you feel sleepy or drowsy in the daytime, then you must have a sizeable sleep debt.” Most of us tend to think that if we are dead tired and fall asleep within minutes of the time our head hits the pillow it is a good sign.
Dement found that those who fell asleep within 5 minutes were suffering from extreme sleep deficiency. These individuals had severely impaired physical and mental reactions due to accumulated sleep debt. Those who fall asleep within 5-10 minutes carry considerable sleep debt and those who fall asleep within 10-15 minutes carry a manageable sleep load. Those who require 15-20 minutes to fall asleep usually have excellent alertness and physical stamina. Bottom line?? SLEEP IS IMPORTANT!
1. Dement, Willian C. , The Promise of Sleep, New York: Dell Trade Paperback, 1999, 57, 60
2. Cauter, Eve Van, et al, The impact of sleep deprivation on hormones and metabolism, Medscape Neurology & Neurosurgery 2005: 7 (1)
3. McAfee, Jim, Sleep and Health, July 2009, Volume 5 Issue 7
. The bit about “screen time” is probably more important than we have guessed. I’m starting – tonight! – to meditate before turning in to see if that might help. 
