The ABCs of Sleep—Understanding a major pillar of health
Sleep is nutrition to the brain. Don’t give your brain the right amount of nutrition and you become a danger not only to yourself but also to others. I literally had my wake-up call to this truth when one afternoon around 2:30 I fell asleep behind the wheel and wrote off three cars—my car and two others. Thankfully, no one was hurt. Before this accident, I had been warned about not getting enough sleep; but the warning went in one ear and came out the next. Even years after such a tragedy, I still forget and fall back every now and then into my old ways of cheating myself on sleep. So, if you are like me, here is your reminder: Sleep is a major pillar of health. Understanding sleep, therefore, is critical to your health and wellness. Here are the basics of sleep to help you understand why sleep is one of the major pillars of your health.
A- Anatomy of Sleep
The anatomy of sleep involves interactions among several structures within your brain.
The hypothalamus, a peanut-sized structure deep inside the brain, contains groups of nerve cells that act as control centers affecting sleep and arousal.
The brain stem, at the base of the brain, communicates with the hypothalamus to control the transitions between wake and sleep.
The thalamus acts as a relay for information from the senses to the cerebral cortex (the covering of the brain that interprets and processes information from short- to long-term memory).
The pineal gland, located within the brain’s two hemispheres, receives the message to increase the production of the hormone melatonin so you can sleep once the lights go down.
The basal forebrain, near the front and bottom of the brain, also promotes sleep and wakefulness, while part of the midbrain acts as an arousal system.
The amygdala, an almond-shaped structure involved in processing emotions, becomes increasingly active during REM sleep.
The biological clock is your body’s rhythm. It is based on a 24-hour day and controls the timing of your sleep, your sleepiness at night, and your tendency to awaken without an alarm in the morning. The biological clock is also called the circadian rhythms, which also influence your body temperature, metabolism, and the release of hormones.
Sleep deprivation affects cognitive ability . A study showed that people who were awake for nineteen consecutive hours were as cognitively impaired as people who were legally drunk. After sixteen hours without sleep, the brain begins to fail.
Dreams are the brain’s way of making sense of the day by replaying and processing mental stimuli in order to extract meaning and create memories. We need to sleep to dream. The brain generates two distinct types of sleep—slow-wave sleep (SWS), known as deep sleep, and rapid eye movement (REM), also called dreaming sleep.
Sleep helps to manage the emotions. But when you are sleep-deprived, these emotions are more difficult to manage. That’s because the regions of the brain that regulate sleep are impacted. These areas are the prefrontal cortex and the amygdala.
For optimal sleep, the ideal room temperature is 60-67 degrees Fahrenheit (15.5-19.4 degrees Celsius) . Your core body temperature synchronizes with the sun setting.
Sleep is genetically determined. However, environmental factors can impact the duration and intensity of your sleep. For example, scientists say some people’s genes increase their stress sensitivity. And that increased stress-response increases the likelihood of poor sleep and developing insomnia.
Hypersomnia is oversleeping, and it is a disorder. Both sleeping too much and sleep deprivation have the same health risks: heart disease, metabolic problems such as diabetes and obesity, depression, cognitive issues including difficulty with memory, and higher mortality rate. Hypersomnia is characterized by sleeping well beyond 7-8 hours. It’s important to have the right balance when it comes to sleep—not too much and not too little.
I- Immune System.
Sleeping less than 6 or 7 hours can weaken your immune system tremendously.
J- Jet lag disorder (JLD)
Jet lag disorder is frequently encountered by air travelers crossing multiple time zones. JLD is characterized by insomnia or excessive daytime sleepiness associated with physical or mental impairment.
K complexes are large brain waves that often occur in response to environmental stimuli such as sounds in the bedroom. Brain waves tell you what is happening inside the brain. K complexes occur during stage 2 of sleep, where we spend half of the time asleep. Sleep 1 is your light sleep, when the temperature of the body begins to drop. Stages 3 and 4 are the deep sleep. And during REM (rapid eye movement), the eyes remain closed but shift from side-to-side. This is the dreaming phase. After REM, you return to stage1 and repeat the cycle. In one night, you can experience 4-5 sleep cycles.
A hint of dim light has been shown to delay the release of nighttime melatonin in humans. Avoid light close to your bedtime. Your room should be completely dark.
Your nocturnal melatonin levels are controlled by the loss of daylight at dusk and the drop in temperature that coincides with the setting sun. A room temperature of around 65 degrees Fahrenheit (18.3°C) is ideal for the sleep of most people, assuming standard bedding and clothing.
Getting quality sleep helps to prevent neurogenerative diseases such as Alzheimer’s and Parkinson’s.
There is an inverse connection between sleep and obesity: less sleep, more weight. Persons who sleep less than 7 hours tend to have a higher body mass index (BMI) than those who receive the recommended hours of sleep. Too little sleep hampers the way your body processes food for energy, particularly blood sugar/ glucose levels.
Obesity can also cause or lead to sleep apnea. Cartoons and comic strips represent sleep with snoring. But did you know loud snoring could be considered an indication of sleep apnea, a disorder in which breathing stops and starts repeatedly during sleep?
BMI -This is your weight in kilograms divided by height in meters squared.
At sleep your brain sifts through memories, forgetting certain things so as to remember what’s important. One way it may do this is by “pruning away” unwanted connections in the brain.
Q-Quality of Sleep
The National Sleep Foundation (NSF) in January 32, 2017 released the key indicators of good sleep quality, as established by a panel of experts. Quality sleep is
- Sleeping more time while in bed (at least 85 percent of the total time);
- Falling asleep in 30 minutes or less;
- Waking up no more than once per night and
- Being awake for 20 minutes or less after initially falling asleep.
Your body repairs and renews cells while you are asleep.
High stress levels can impact the quality of sleep, leading to overactive adrenals. Lack of sleep and overactive adrenals lead to excess cortisol (aka stress hormone), thus taxing the sympathetic nervous system that controls “fight or flight”. The body remains always on high alert. These high cortisol levels can affect the cardiovascular, endocrine, immune, and nervous systems and cause the following:
- Obesity in adults and children
- Diabetes and impaired glucose tolerance
- Cardiovascular disease and hypertension
- Anxiety symptoms
- Depressed mood
- Alcohol use
While you are asleep, your brain is housecleaning. It is removing toxins that accumulate during waking hours, some of which are linked to neurodegenerative diseases. During sleep, the space between brain cells increases, allowing toxic proteins to be flushed out. It’s possible that by removing these toxins from the brain, sleep may stave off neurodegenerative diseases like Alzheimer’s.
Lack of sleep leads to unbalanced hormones:
- Insulin is increased (due to short-term insulin resistance), so you store more fat.
- Leptin is reduced, so you eat more because there’s nothing telling you to stop.
- Ghrelin is increased, so you eat more because it’s telling you to do so.
- Cortisol is increased, so you eat more and use muscles for energy.
- Human Growth Hormone is reduced, so you store more glucose as fat.
Vitamin D has proven to improve sleep quality. You can boost your vitamin D intake by spending just 30 to 60 minutes in direct sunlight or, for those who live in colder places, by taking vitamin D supplements.
Researchers at Binghamton University in New York discovered that people who are sleep-deprived tend to worry more and have more difficulty fighting off repetitive negative thoughts.
Exercise improves sleep. But exercise 3 hours prior to bedtime. Exercise raises the body’s core temperature, keeping you awake.
Though the amount of sleep each person needs varies, most people need 7-9 hours of sleep. It is best to wake up and go to bed the same time every day, even on weekends.
Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. https://www.ncbi.nlm.nih.gov/books/NBK19961/
Air travel: effects of sleep deprivation and jet lag.https://www.ncbi.nlm.nih.gov/pubmed/24081353
Brain Basics: Understanding Sleep
Central Sleep Apnea. https://medlineplus.gov/ency/article/003997.htm
Genetics of Sleep and Sleep disorders https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3153991/