A Few Facts about Sleep
October 17, 2023
My bedtime is fast approaching but before I go to sleep, I want to share a few thoughts about sleep from the book Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker PhD in Neurophysiology.
Dr. Walker has been studying sleep for 20 years. After observing the brain activity in older adults in the early stages of dementia, he began to question whether sleep disruption was causing the progression of the disease.
1. Sleep Recommendations
- It is generally recommended by the sleep medicine community to get 8 hours of sleep per night, but individually it can range from 6-8 hours.
- Current sleep statistics show that 2 out of 3 adults get less than 8 hours of sleep per night!
2. Sleep and Its Effect on Health - The Health Consequences of Getting Less Than 8 hours of sleep including:
- Decreased immune function
- Increased risk of cancer
- Increased risk of Alzheimer’s Disease
- Increased risk of Coronary Disease
- Increased risk for Depression and Anxiety
- Increased hunger—>leading to weight gain
- Increased risk of accidents*
- *Drowsy driving is responsible for more car crashes than driving under the influence of drugs and alcohol combines.
3. Healthy levels of sleep promotes:
- Psychological health
- The ability to learn and memorize
- Healthy Insulin & Glucose levels
- A healthy microbiome (plays a role in metabolism and immune function)
- Lowered blood pressure
- Improved memory & concentration
4. Your Lifestyle affects your Circadian Rhythm
(a 24 hours internal clock within the brain that produces tiredness or alertness at specific periods during the day)
- The circadian rhythm also plays a role in eating, drinking, mood, urination, body temperature, metabolic rate, and the release of various hormones
- The peak point of the circadian rhythm is in the early afternoon and sunlight is the main environmental factor that plays a role in keeping the cycle at baseline. *
- *Human Experiments show that even living in total darkness, signs of a circadian cycle exist
- Both the chemical Adenosine and secondary environmental factors including: food, exercise, temperature, and habits of social interaction play a role in your desire to sleep or stay awake
- 40% of the population are more alert in the mornings and about 30% are more alert in the evening-unfortunately in our society we neglect these differences operating on a universal time that favors early risers. So “evening people” lose out on hours of restoration due to more difficulty falling asleep at night.
- A chemical released by the pineal gland in response to darkness that functions as a signal to the body that sleep is near
- It is common to supplement with Melatonin
- Melatonin does not keep you asleep, its function is to time sleep and induces feelings of sleepiness, not sleep depth
- The morning sunlight turns off Melatonin production
- Traveling with Melatonin: Jet lag happens when we enter a new time zone but our circadian rhythm is adapted to our previous time zone*
- *When entering a new time zone, your circadian rhythm adjusts by only 1 hour per day
- To adjust to new time zones, the author suggests that you take a melatonin supplement around 7-8 p.m. of the time zone your circadian rhythm is accustomed to (sleep will still be delayed but it will help get a few hours of sleep)
- Studies have shown that crossing time zones constantly causes:
- brain shrinkage in areas related to learning and memory
- short term memory impairment
- increased rates of type 2 diabetes and cancer
6. Determining Enough Sleep
- The author suggests asking yourself these 2 questions to assess if you are getting enough sleep
- Could you fall asleep at 10 or 11am?
- Can you function optimally without caffeine before noon?
- If you answer yes to the first question, or no to the second question, you should revise your sleep routine
- Other Sleep Quality Assessment Tips
- If you find yourself unable to wake without an alarm clock past a certain time, you likely need more sleep
- If you notice excess forgetfulness, its likely you’re not getting adequate sleep
- If you are getting a full 8 hours of sleep, but still experience fatigue, you might suffer from a sleep disorder like insomnia, disordered breathing, or sleep apnea. Consult your doctor in these cases
7. The Sleep Cycle
- Types of Sleep
- 1. Non-rapid eye movement (NREM) - has 4 stages that increase in depth, the deeper you go, the harder to wake up-slower waves of sleep or the storer of information
- 2. Rapid eye movement (REM) - known as the building phase of sleep, in the latter portion of the sleep cycle-fast frequency of wakefulness or the sensory receiver of information
- The Sleep Cycle
- REM and NREM states of sleep compete in 90-minute shifts throughout the night. In the first phase NREM sleep dominates but as the night goes on, eventually REM sleep dominates and NREM loses its frequency. By shifting phases during the sleep cycle, it is theorized that the brain is cleaning out and building neural circuits, kind of like housecleaning unimportant information, and nailing down the important information. If your sleep is shortened then there will be major interruptions in the maintenance of the nervous system.
- During the slower frequency of NREM sleep information in the short-term memories begin encoding themselves into the long-term memory.
8. Sleep in Different Organisms
- The duration of sleep is affected by the type of diet, predator/prey balance, metabolism, nervous system complexity, the amount of waking demands
- Even bacteria have been observed to have cycles that respond to day and night
- Elephants sleep for about 4 hours a day
- Tigers and lions sleep for 15 hours a day
- The brown bat sleeps for 19 hours a day
- Squirrels sleep for about 16 hours a day
- Guinea pigs and baboons sleep 9.5 hours a day
- Giraffes sleep 4-5 hours a day
9. Sleep Deprivation and the Brain
- Concentration is the most immediate effect observed.
- Running on less than 5 hours of sleep increases your chance of a car crash by 3-fold and operating on 4 hours of sleep or less, increase the chance by 11.5-fold
- In the U.S., every 30 seconds there is a car crash caused by drowsy driving
- Every hour someone dies in a traffic accident in the U.S. due to an error related to sleep loss or micro sleep-a quick lapse in concentration-which only lasts a few seconds, is accompanied by a half or fully closed eyelid, and a total loss of sensory perception.
- Drowsy driving is responsible for more car crashes than drugs and alcohol combined
- About 80% of U.S. truck drivers are overweight, 50% are clinically obese, both diagnoses are closely linked with sleep apnea
- After pilots have been staring into darkness-a well-known sleep aid-68% of crashes occur on landing
- Alzheimer’s Disease risk increases with a lack of sleep, 1 in 10 adults suffer from this horrible disease, and over 60% of Alzheimer’s patients are diagnosed with at least one sleep disorder
10. Sleep Deprivation and the Body
- Sleep loss is shown to increase the heart rate, blood pressure, and weaken the coronary arteries.
- 2011 study-shorter sleep is associated with a 45% increase risk of developing coronary artery disease
- Growth hormone’s peak release happens during the overnight hours of sleep, therefore less sleep hinders growth and repair of the body
- Blood sugar regulation is negatively affected by short sleep and high sugar levels tax organs and tissues-common to see blindness, nerve disease, kidney failure, high blood pressure and heart disease happen
- A study of participants who slept 4-5 hours per night for a week showed a decreased receptivity to insulin, the hormone needed for maintaining healthy blood sugar levels.
- Less sleep promotes weight gain because Ghrelin (hunger promoting) increases and Leptin (signals feeling of fullness) decreases
- Sleep deprived people eat more food than people who have had adequate sleep-this may be due to an increase in endocannabinoids that accompany sleep loss, which are associated with an increased appetite
- Researchers found a 30-40% increase in cravings for salty and sugary foods and MRI scans show an increase in the impulsive centers of the brain, and a decrease in the higher order thinking areas when sleep deprived
- In the area of reproduction, Testosterone significantly drops in young males sleeping 5 hours per night for only 1 week. Generally, sleep disorders and low Testosterone go hand in hand and poor sleep quality has been seen to reduce sperm count by up to 29%
- In women certain reproductive sex steroids decrease by 20%, and shift work, causing irregular sleep cycles increases the chance of abnormal menstrual cycles by 33%, and fertility issues increase by up to 80%
- Immune System dysfunction issues abound with sleep loss including rendering a flu vaccination less effective and increasing probability of catching a virus. Circulating Natural Killer Cells (responsible for killing off harmful cell growth) were found to be reduced by 70% after a single four-hour sleep, compared to a full eight-hour sleep.
- Sleep loss inhibits full gene expression, resulting in body destabilization and an increase risk for certain diseases and cancers
- Pain is exaggerated and is more apt to cause disruption in a sleep deprived individual. Pain is often treated in the hospital, the worst place for sleep due to loud noises and sometimes frequent awakenings. Dr. Walker suggests hospital offer patients a sleep eye mask and ear plugs upon admission.
11. Sleeping Pills, Artificial Sleep, Therapy over Pills
- Sleeping pills do not provide the restoration of natural sleep, instead like alcohol they create sedation and MRI scans show that under the influence of sleeping pills shows a decrease in deep brainwave activity, leading to daytime grogginess and slowed motor skills the next day
- Rebound insomnia (when you have difficulty falling asleep after having used external substances to aid sleep for a while) is common when patients stop taking sleeping pills
- A study observed that people who took Ambien were shown to have weakened brain connections by 50% after learning, compared to a group who had natural sleep
- Another study found that people using RX sleep drugs are significantly more like to die and to develop cancer than those who do not, due to the lack of restorative sleep
- The author recommends behavioral therapy methods over sleeping pills or CBT-1; Cognitive Behavioral Therapy for Insomnia including: reducing caffeine, reducing alcohol, room temperature control, reducing screen time before bed, establishing a regular sleep schedule, going to be only when sleepy, not lying in bed too long if sleep does not occur, avoiding daytime naps, mental deceleration before bed, and avoiding clocks near your bed.
12. Good Sleep Practices
- Waking up and going to sleep at the same time of day is said to be the most powerful sleep practice that you can develop.
- Exercise helps facilitate a deeper restorative sleep but you should avoid exercising within 2 hours before bed; it raises your core body temperature.
- A low carb high fat diet increases NREM and decreases REM sleep and sleep fragmentation.
This was an excellent book, well written and easy to follow with interesting facts and help that can be incorporated into everyone’s life.
Good night, sleep well, your quality of life and longevity depends on it!
Susan Merenstein, Pharmacist and Owner
Murray Avenue Apothecary