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Sleep or Die!

Posted Aug 15 2013 6:21am
We spend over a third of our lives sleeping.  If you live to be a nonagenarian you'll have spent approximately 30 years asleep.  It's such a substantial part of life, interconnected to virtually every part of one's health, yet why we need to sleep remains a medical mystery. William Dement, founder of Stamford University Sleep Center , says "As far as I know, the only reason we need to sleep that is really, really solid is because we get sleepy."  We do know some of the functions of sleep science
  • getting some zzz's instigates a heightened anabolic state during which the body rejuvenates and grows
  • sleep helps with the processing of memories and cognitive functions 
  • it allows us to dream
Our sleep cycles are governed by the  circadian rhythm . This is an internal 24 hour clock residing in every cell of your body responsible for overall alertness.  It coincides very closely to the sun's schedule. For most of human history we slept in 2 distinct stages . Before the electric light bulb was invented, most people went to sleep shortly after nightfall and woke up 4 to 5 hours later.  They would stay up and do various things (sex mostly) for about an hour before going back to bed for their 'second sleep'. Sometime around sunrise they'd wake up refreshed and ready for the day.  Adult humans need roughly 1 hour of sleep for every hour they are awake - about 7-9 hours per night (teenagers and kids need more sleep). How much you sleep on a regular basis has a huge impact on your weight, diet choices, cognitive ability, emotions and even disease rates. Exposure to artificial light and the ability to travel quickly through time zones (a la jet setting) have unfortunately befuddled our clocks and screwed up our sleep.

Sleep Factoids:
  1. Science has no answer as why we need sleep. Although we know it is vital, sleep seemingly goes against every survival instinct.  While we are dreaming away we are not getting food, protecting ourselves and/or procreating (sleep walking experiences excluded). Many animals sleep with only half their brain 'off' for fear of predators.
  2. Randy Gardner, in 1965, stayed awake for 11 days - a world record.  During this time he experienced delusions, paranoia, cognitive deficits and aggressiveness.  
  3. After pulling an 'all nighter' blood pressure will elevate, metabolism will go down, body temp drops, immune system gets weaker and many people claim to get uncontrollable cravings for carbohydrates .  
  4. Sleep has 5 stages that cycle over roughly 90-100 minute periods.
  5. During REM sleep you release hormones to effectively paralyze your limbs so you don't act out your dreams.  
  6. Overexposure to night light (specifically LEDs, LCDs and florescent lights) has been linked to cardiovascular disease, diabetes, obesity and cancer
  7. Sleep deprivation is linked to signs of " skin aging and slower recovery from a variety of environmental stressors." 
  8. Sporting teams and athletes that play in their own time zone during periods of circadian boosts (9 AM til 2 PM  & 6PM til 10 PM) are a lot more likely to win - its called the circadian advantage
  9. About 1-3% of the population ( short-sleepers ) have a mutated gene that allows them to function normally on less than 6 hours of sleep.  
Working late into the evening under light that is bright enough to "read a book by" will confuse your circadian rhythms and lower your blood level of melatonin (the sleep hormone).  These lower levels of melatonin will affect the body's production of estrogen, human growth hormone and testosterone.  Not good. Chronically putting yourself in this position (i.e. working the overnight shift at 7-11) will weaken your immune system and put you at higher risks for many cancers and other diseases . Florescent bulbs, LCD and LED lights (in your computer, TV, phone screens and digital clocks) emit the most deleterious light because they radiate a higher level of blue on the spectrum.
"Light at night is bad for your health, and exposure to blue light emitted by electronics and energy-efficient lightbulbs may be especially so....Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours)." - Harvard Sleep Center
Even light as bright as a small table lamp can interfere with an individual's circadian rhythm and melatonin secretion.  Turning down all your lights and electronics at least 60 minutes prior to bedtime will help you sleep better.  Using lights that are warmer on the spectrum (with less or no blue) have been shown to to have a minimal but quantifiable effect.  If you can't turn off the TV or computer, purchase filters to place over the screen to block the blue light. Perhaps the best option is to read a boring book under an old fashioned incandescent bulb set to dim. My out dated "Clinical Neurology of the Older Adult" is sure to put you to sleep.   

Sleep and Weight Loss

Mountains of medical and research evidence suggest compelling links between sleep and weight.  The quality and duration of your sleep may " silently orchestrate a symphony of hormonal activity tied to your appetite ".  Four major hormones responsible for appetite and weight control (leptin, grhelin, cortisol and insulin) are all negatively affected by lack of good sleep.  Studies show if you don't get enough sleep your body will store more food as fat , increase your appetite , and decrease your sensitivity to insulin .  It's a double whammy: lack of proper sleep increases your hunger while decreasing your ability to feel sated.  To top it all off, the foods your body craves when sleep deprived are typically higher in sugar and more likely to be stored as belly fat !

Note: If you sleep 5 hours or less per night you will have a 50% increased chance of becoming obese. 

Lesser Known Sleep Tips:
  • Studies report most people sleep better in rooms 60-68 degrees Fahrenheit
  • Rid yourself of evening blue light exposure (TV, computer, bright clock, and florescent and LED bulbs) or turn it all off at least 1 hour before bedtime
  • If you work late under blue light spectrum bulbs wear blue light blocking sunglasses 
  • Got to bed earlier to get more in rhythm with your natural sleep cycles (and get up soon after the sunrises)
  • Have a consistent sleep schedule where you wake up and go to sleep at the same time everyday....even on weekends
  • Sharing a bed with a spouse, child or pet (especially snakes and rodents) makes good sleep more difficult
  • Getting adequate exposure to natural light during the day (especially the morning) will help regulate your circadian rhythm
Which position do you sleep in most? 

Have trouble falling asleep? Check out this site with effective techniques to help:


1. Randall, David. Dreamland: Adventures in the Strange Science of Sleep;  W.W. Norton & Co. 2012.
2.  Harvard's Sleep Center
3. Stanford's Center for Human Sleep Research 
4.  TED Talk: Russell Foster - Why do we sleep?

Doug Joachim - NYC
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