Good Night Sleep
Good Night Sleep—The Most Important Predictor of Longevity
There is strong evidence supporting the argument that the amount of time you sleep—even more than whether you smoke, exercise, or have high blood pressure or cholesterol levels—could be the most important predictor of how long you'll live.
On average, adults need 7-9 hours of sleep to stay healthy every night. Those who slept 5 hours or less a night had a 15% greater mortality risk compared with those sleeping 7 hours. While not getting enough sleep is clearly associated with increased health risks, so is getting too much sleep[17]. Those who slept 9 hours had a 42% increase in mortality risk.
Note that it's not only how many hours you sleep is important, but also when you sleep is important. For example, nationally, night-shift workers have a 30% higher incidence rate of cancer.
Figure 1. Your Body's Internal Clock and How It Affects Your Overall Health
Figure 2. DNA damage is a homeostatic driver for sleep, and Parp1 pathways can sense this cellular pressure and facilitate sleep and repair activity (Source: [31])
Why Good Night Sleep Is Essential?
A good night sleep can relax, recharge, and repair. Your body can't do this during the day. Researchers have found that a good night sleep[1-3]:
Helps in healing and repair of our heart and blood vessels
Ongoing sleep deficiency is linked to an increased risk of heart disease, kidney disease, high blood pressure, and stroke.
Helps fighting obesity
Chronic sleep deprivation may cause weight gain by affecting the way our bodies process and store carbohydrates, and by altering levels of hormones that affect our appetite.
One study of teenagers showed that with each hour of sleep lost, the odds of becoming obese went up.
Scientists are now convinced that increased sleep deprivation is related to the obesity epidemic[7,8,22].
Helps our immune system
Our immune system releases proteins called cytokines which can help us deal with stress, fight infections and decrease inflammation in the body. When we don't get enough sleep, these protective proteins and other important infection-fighting cells are reduced.
It is known that acute and chronic sleep deprivation can decrease body's number of natural killer cells and reduce activity of those natural killer cells. Hence make us more vulnerable to colds and infections.
Supports healthy growth and development
Deep sleep triggers the body to release the hormone that promotes normal growth in children and teens. This hormone also boosts muscle mass and helps repair cells and tissues in children, teens, and adults.
Sleep also plays a role in puberty and fertility.
As soon as you hit deep sleep, about 20 to 30 minutes after your first close your eyes and then again during each sleep cycle, your pituitary gland starts to release high levels of growth hormone—the most it will secrete at any point in the day[5].
Too little sleep may fuel insulin resistance
Sleep deficiency results in a higher than normal blood sugar level, which may increase your risk for diabetes[21].
After four nights of sleep deprivation (sleep time was only 4.5 hours per night), study participants' insulin sensitivity was 16 percent lower, while their fat cells' insulin sensitivity was 30 percent lower, and rivaled levels seen in those with diabetes or obesity[16].
Researchers at the University of Chicago found that losing just 3 to 4 hours of sleep over a period of several days is enough to trigger metabolic changes that are consistent with a prediabetic state.[6]
Helps learning and memory
Sleep helps the brain commit new information to memory through a process called memory consolidation.
In studies, people who’d slept after learning a task did better on tests later
Helps mental acuity[5]
Lack of sleep played a role in the Three Mile Island meltdown, the Exxon Valdez oil spill, and the explosion of the Challenger space shuttle.
Helps your mood[9]
Sleep deficiency may
Result in mood problems and depression
Make people more vulnerable to the development of anxiety disorders
Worsen ADHD (Attention deficit/hyperactivity disorder) symptoms
5 to 10% of the adult population in Western industrialized countries suffer from chronic insomnia, making it another likely contributor to the depression epidemic.
Studies report that about 90% of patient with major depression have difficulty initiating and maintaining sleep.
Improves Circulation[5]
Sleep deprivation leads to poor circulation (circulation is how hair and skin get their nutrients), poor sleep is linked to facial wrinkles and thinning hair.
References
The Sleep Doctor's Diet Plan by Michael Breus, PhD.
Knutson, K.L. Impact of sleep and sleep loss on glucose homeostasis and appetite regulation. Sleep Medicine Clinics 2007;2(2):187-97.
Patel, S.R., F.B. Hu. Short sleep duration and weight gain: A systematic review. Obesity (Silver Spring) 2008; 3:643-53.
Watanabe, M., H. Kikuchi, K. Tanaka, M. Takahashi. Association of short sleep duration with weight gain and obesity at 1-year follow-up: A large-scale prospective study. Sleep 2010; 33:161-67.
Spontaneous Happiness by Andrew Weil, MD
Shanafelt, T., D. Barton, A. Adjei, C. Lprinzi. Pathophysiology and treatment of hot flashes. Mayo Clinic Proceedings 2002;77:1207-18.
Lai, H.L., M. good. Music improves sleep quality in older adults. Journal of Advanced Nursing 2004; 49(3):234-44.
Blumenthal, M., A. Goldberg, J. Brinckmann. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Integrative Medicine Communications, 2000, pp. 226-29.
Burkhart K, Phelps JR. (26 December 2009). "Amber lenses to block blue light and improve sleep: a randomized trial."
Too Little Sleep May Fuel Insulin Resistance (Dr. Mercola)
Impaired Insulin Signaling in Human Adipocytes After Experimental Sleep Restriction: A Randomized, Crossover Study (Annals of Internal Medicine)
A week's worth of camping synchs internal clock to sunrise and sunset, study finds
Consistent Sleep, Wake Times Linked With Lower Body Fat Levels
Scientists have found that, when the mouse brain is sleeping or under anesthesia, it’s busy cleaning out the waste that accumulated while it was awake.
On average, we’re getting one to two hours less sleep a night than we did 50 to 100 years ago and 38 minutes less on weeknights than we did as little as 10 years ago.
When our sleep is disturbed, whatever the cause, our cleaning system breaks down.
The body actually has many cellular clocks scattered throughout its tissues—in the liver, pancreas and elsewhere. Disruptions in any of the secondary clocks may increase an individual's risk of developing heart disease, diabetes or depression, among other conditions.
Iris (see the top video)
Why the clocks changing is great for your brain
Winter awakening with the aid of an artificial light (dawn simulation) was able to restore the CAR (i.e. cortisol awakening response).
This finding is consistent with light exposure, especially morning light, being the most effective treatment for the winter blues.