Sleep

Posted on    by

What to avoid or do less

  • Stress.
  • Within 2-3 hours of sleeping: dinner, exercise.
  • Late night: snacks, caffeine, alcohol and electronics (blue light, stress).

What to improve or do more

  • Consistent sleep schedule.
    • Sleep close to sunset (9-10 PM); wake up close to sunrise (6-7 AM).
    • 7 days a week.
  • Quantity.
    • At least 8 hours in bed (ideally aim for 8 hours of sleep, not just time in bed).
  • Quality.
    • Increase melatonin: dark, cool room.
  • Other.
    • Take naps.
    • Increase melatonin: mix of supplements.
    • Measure: resting heart rate, HRV, body temperature.

Science of sleep

  • Sleep.
    • A barrier exists between you and your environment.
    • You can be awakened.
    • Predictable neuron patterns. (sleep architecture, stages).
  • Duration:
    • Historically maybe up to 10 hours a day.
    • Sleep more in winter than in summer.
    • Culturally shifted to average of about 7 hours a day.
  • How much is needed:
    • Adults: 7-9 hours.
    • New-born: 12-18 hours.
    • 3 mts – 1 yr: 14-15 hours.
    • 1-3 yrs: 12-14 hours.
    • 3-5 yrs: 11-13 hours.
    • 5-12 yrs: 10-11 hours.
    • 12-18 yrs: 8.5-9.5 hours (none get this, schools need to start later).
  • Sleep stages:
    • Non-REM.
      • Stage 1 and 2 – lightest.
      • Stage 3 and 4 – deep, restorative.
    • REM.
  • Sleep cycles:
    • Go through stage 1-4 on non-REM.
    • Then after 70 min, you go back to stage 2 on non-REM.
    • Then you will briefly transition to REM sleep.
    • Then you flip flop between non-REM and REM.
      • non-REM, back to REM, back to non-REM, back to REM, etc.
  • Every 90 minutes.
    • Your brain cycles between non-REM and REM sleep.
    • In first half of night, majority of 90 minute cycle is deep non-REM.
    • In the second half of the night, the majority of cycle is REM.
    • When you sleep determines what part of cycle you get more of.
      • Early: more deep.
      • Later: more REM.
  • Brain waves:
    • Alpha – when you first lie down.
      • Frenetic high-frequency electrical activity with small amplitude.
      • When eyes close, back of brain (visual brain), stops processing.
      • Frequency slows from 50 cycles/sec down to 10 cycles/sec.
    • Theta – starts in Stage 1 and 2.
      • Cycles down to 6-7 cycles/sec, amplitude getting bigger.
      • Synchronous bursts of electrical activity, sleep spindles (a second and half long).
    • Delta – starts in Stage 3 and 4.
      • 1 or 2 cycles per second, but size of waves are huge.
      • Longer wave length allows for long distance information transfer.
  • Learning:
    • Stage 2.
      • Refreshes and prepares your brain for future learning and memory.
    • Stage 3 and 4.
      • Consolidates new learning and memory from previous day.
  • Process leading up to sleep:
    • Decrease in blue light stimulates pineal gland.
      • Pineal gland releases melatonin.
    • Release of melatonin stimulates adrenal gland.
      • Adrenal gland reduces release of cortisol.
    • Drop in:
      • Body temperature.
      • Heart rate.
      • Blood pressure.
      • Blood sugar.
    • GABA reduces activity in the neocortex.
      • Calming effect.
    • Increase in immune system.
  • Sleep is a balancing act between adenosine, cortisol, and melatonin:
    • Adenosine:
      • During the day, as you use up ATP, you build up adenosine.
      • Levels gradually increase throughout the day.
      • As you run out of food / ATP, adenosine signals drowsiness.
      • During sleep, the body metabolizes adenosine, until levels are low again.
    • Cortisol:
      • You want to wake up at a low, increasing level
      • You want to go to bed at a decreasing, low level
      • First two hours of waking, you should have a surge in cortisol
      • Peaks about an hour after getting up.
      • Then a gradual tapering off leading up to bedtime.
      • See also “The Drive with Peter Attia – Robert Sapolsky“.
    • Melatonin:
      • You want melatonin to rise at night.
      • Melatonin is secreted by the pineal gland.
      • It is secreted in the absence of light, specifically blue light.
    • In summary, sleep associated with:
      • High adenosine.
      • Low cortisol.
      • High levels of melatonin.
  • If these cycles are out of balances: sympathetic state and insomnia.
    • Sympathetic state “turned up” too far.
    • Spikes in cortisol (before bed or when waking during sleep) related to insomnia.
    • Unclear if sympathetic state drives high levels of cortisol or vice versa.
      • Fix sympathetic state: behavioral solutions (meditation, etc.)
      • Fix cortisol: supplements (phosphatidylserine, etc).
    • HRV may be helpful indicator of sympathetic vs parasympathetic state.
  • Biochemical pathways:
    • Tryptophan -> 5HTP -> serotonin -> melatonin -> lower cortisol.
    • Requires vitamin D3 (sun) and magnesium as co-factors.
  • During deep sleep:
    • Primary time when testosterone and growth hormone gets produced.
    • Immune system is at highest level.
    • Repair mode.
  • Body temperature:
    • Body temperature drops throughout the night.
    • Low in temperature about 2 hours before wake up, then gradual rise.

Bad sleep

  • Sleep “cleans up” the “damage” from being awake.
    • Cleans up bad protein aggregations that build up during the day.
  • Lack of sleep causes the quickest reduction of health.
    • Rats deprived of sleep die after 9 days.
    • In this context, REM sleep may be the most important ingredient of sleep.
  • For many people, sleep deprivation has a wide range of consequences.
    • Macro: slowly developing diseases, behavior.
    • Micro: cellular pathways and interaction.
    • Wide range of impairments.
      • Disease, performance, depression, etc.
      • Memory, spatial attention, emotional stability, judgment, and decision making (see below).
  • But not all people show impairment in all those areas.
    • Some people may be more or less affected than others.
  • Lack of sleep is correlated with:
    • Stress (see “The Drive with Peter Attia — Robert Sapolsky“).
      • Body being more driven by sympathetic nervous system.
      • Release of adrenaline, cortisol spikes.
      • Cortisol: builds up fat, breaks down muscles.
      • Negative feedback loop: more cortisol, less sleep -> less sleep, more cortisol.
    • Impaired insulin signaling (glucose absorption):
      • Lowers release of insulin in pancreas.
      • Lowers tissue sensitivity to insulin.
      • Impairs glucose disposal, inferior fuel partitioning.
    • Bad diet:
      • Sleep deprivation sends “fake starvation signal”.
        • Ghrelin hormone up (eat more).
        • Leptin hormone down (satiated less).
      • Changes your appetite profile, increases day-time hunger.
        • Caloric intake higher and worse food choices.
        • Weight gain.
    • Reduction in growth hormones.
      • Causes changes in metabolism, body composition.
      • Less testosterone -> more fat -> fat drives testosterone to turn into estrogen -> more estrogen -> brain signal -> lower testosterone etc.
    • Lowers reproductive hormone levels.
      • Sex hormones are highly dependent on sleep.
      • Lowers testosterone (see above).
      • 6 hours of sleep lowers libido by 30-40%.
    • Lowers immune system response.
    • Less exercise.
      • Lower discipline, less motivated and reduction in performance.
      • 6-7 hours of sleep equivalent to impact of 1 alcoholic drink.
    • Negative epigenetic impact.
      • Downregulate immune system genes.
      • Upregulate inflammation, stress.
    • Negative athletic performance impact:
      • Harder to sustain attention, make quick decisions, lessens spatial sense and judgment.
    • Negative decision making impact:
      • Less control of impulsivity.
      • Lower creativity.
      • Less motivated.
    • Faster aging.
      • Biological age > chronological age.
      • Skin, heart, telomeres all age faster.
  • Alcohol and sleep.
    • Alcohol is a sedative.
    • It fragments sleep (get up and pee) and blocks REM sleep.
    • Negatively impacts: resting heart rate, heart rate variability, temperature and respiratory rate.
  • Caffeine and sleep.
    • Caffeine blocks adenosine receptors.
    • Blocks signal of adenosine build-up.
    • Caffeine has a half life on average for most people of about six hours.
    • It has a quarter life of 12 hours…

Good sleep

  • Four pillars of sleep:
    • Regularity: consistency of schedule.
      • 7 days a week, fixed bed-time and wake-up time.
    • Continuity: waking up many times per night?
    • Quantity: total sleep, across sleep stages.
      • 7-9 hours.
      • Go to bed when the sun goes down, around 9.30 PM.
      • Wake up when the sun comes up, around 6-7 AM.
    • Quality: of the “electrical signature” of sleep is.
  • Increase melatonin.
    • Darken the room.
      • Avoid longer wavelength (blue) lights.
      • Longer wavelength light puts the breaks on melatonin release more than warmer colored lights.
      • Absence of blue light is a signal to brain to release melatonin, start sleep cycle.
    • No electronics.
      • Less blue light.
    • Cool down the room.
      • 18-19 degrees Celsius according to studies…
      • Cold mattress – Chili Pad.
  • Increase GABA – decrease brain activity.
    • No electronics.
      • Less stress.
  •  Naps.
    • May be good (but may make it harder to fall asleep).
    • May help with learning (consolidates concepts into long-term memory).
    • At least 20 minutes, up to 90 minutes (one sleep cycle).

Supplements

  • Sleep drugs are typically not a great solution.
    • Sleep system is very complex.
    • Drugs usually address only one of the many relevant pathways.
  • Supplement typically try to enhance the melatonin pathway.
    • Melatonin.
      • May help the timing of your sleep.
      • By itself, doesn’t necessarily change the quantity and the quality of sleep.
      • User case: jet lag, old age (flatter circadian rhythm), excess blue light (electronics).
    • Vitamin D3.
    • Magnesium.
    • L-tryptophan.
    • 5HTP.
    • GABA.
  • Doc Parsley’s Sleep Remedy – combines all of them.

Sleep types

  • There may be genetic “chronotypes”.
    • Morning or evening person (test).

Sources:

 

Leave a Reply