If I tell you that there is a drug that will help you:
Improve memory and learning
Reduce stress and regulate emotions
Fight off diseases like cancer, diabetes, Alzheimer’s
Regulate your weight
Will you buy said drug? I bet that there are people who will spend millions on any of the benefits outlined above. Investors have already poured millions into researching cures for cancer or creating enhancement drugs. What if I tell you we all have access to the drug aforementioned, only that it is not a drug, it is sleep.
After experiencing periods of sleeplessness in my youth, I have always been conscious about improving the quality of my sleep. Even so, upon encountering a book that Bill Gates recommended titled Why we sleep by Dr. Matthew Walker, I was surprised by how much I did not know about our nightly slumber.
Sleep is not a nice-to-have luxury, but a life-supporting function of our bodies. With many advantages that a full night of rest can bring, there are short-term and long-term consequences of pulling an all-nighter or consistently sleeping less than 7 hours a day.
The danger of sleep deprivation
Lack of sleep kills
Car crashes are among the leading cause of death in many developed nations. Drowsy driving can have the same severe effects as drunk driving, if not worse. However, countries around the world only have regulations in place to stop drinking and driving, not sleepy driving.
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It is even worse when you drink and drive, all awhile, not getting enough sleep. Simulation, in which four groups were tested in their driving skills, included the following four groups: (1) eight hours of sleep, (2) four hours of sleep, (3) eight hours of sleep plus alcohol, (4) four hours of sleep plus alcohol. The expectation was that the effect of group (4) is the sum of the group (1) and (2). It was not the case; the impact of alcohol consumption coupled with sleep deprivation is not additive but multiplicative.
The next time you sit behind the wheel without an insufficient amount of sleep, remember this graph. Research by the AAA Foundation in 2016 showed that by sleeping 4–5 hours, you increase the chance of car crash by 4.3 times. That figure rose to a whopping 11.5 times when operating under 4 hours of rest.
Similar to drunk people saying, “I am not drunk,” you do not know how sleep-deprived you are when you are sleep-deprived.
You risk developing serious health problems
When we sleep, a heart rate of 40–50 BPM is considered normal compared to the average waking heart rate of 60–100 BPM. The longer time you spend awake, the more pressure you put on your cardiovascular system. This significantly increases the risks of heart diseases such as heart attack, heart failure, stroke, high blood pressure.
You all know that sugar is dangerous to your health, but it is even more so in your bloodstream. A high amount of sugar in the blood has been linked to harms to the tissues and organs of your body, worsens your health, and shortens your lifespan. Insulin helps in triggering cells to absorb sugar (glucose) from the blood, thus reduce the harm of sugar. Lack of sleep, however, disrupts the effectiveness of insulin to trigger the absorption of glucose and leads to weight gain and diabetes.
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Sleep deprivation has also been linked with Alzheimer’s disease. Patients with Alzheimer’s disease have a protein called beta-amyloid built up like a clump in certain parts of their brains. One of the said parts is called the hippocampus, the part of the brain associated with the formation of new memory. Although scientists are still debating whether sleep-loss is a byproduct of Alzheimer’s or the cause of it, one function of sleep is helping the brains flush out metabolic debris, one of which is beta-amyloid. It is then argued that sleep may help or delay the development of Alzheimer’s disease.
There are many other health issues linked to sleep-deprivation such as cancer, the weakening of immune systems, alterations of genes & DNA, and negative effects on the reproductive systems.
The benefits of sleep
Sleep improves your memory and learning
We have three different types of memory, including sensory memory, short-term memory, and long-term memory.
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Sensory memory is the data your body received from your five senses: vision, hearing, smell, taste, and touch. These memories are short-lived (usually only last for 1/5–1/2 second), and not all are transferred to short-termed memory. For example, when reading a page, you can see all of the content at once, but only some of them got transferred to your short-term memory.
Short-term memory is retained longer than sensory memory, typically lasts for 15–30 seconds. We can usually keep 2–8 pieces of information in our short-term memory. It is through processes called rehearsal and consolidation that memory is transferred and safely store in long-term memory.
Long-term memory can last for a long time, with memories lasting for decades. Sleep is essential in the transfer of short-term to long-term memory. Imagine your short-term memory is like a sponge. At the end of the day, when you sleep, the “water” that you “absorb” during the day will be transferred to your “storage tank” (long-term memory). It’s then crucial that you “squeeze” your “sponge” before you learn so that it can absorb more water, as well as after you learn so that the knowledge can be stored away.
“Squeezing” the sponge is the equivalent of sleep.
Experiments have shown that the process of transferring memories still happens 3–5 days before you learn something. So by skipping or shortening your sleep, you risk throwing away knowledge, you worked hard to acquire. Students pulling an all-nighter to cram for the exam might be able to recall some information the next day, but they will often remember far less in the long run.
Sleep increases your longevity
This is almost opposite to what we discussed earlier about the harmful effect of sleep deprivation.
Sleep helps in the effectiveness of insulin, thus reduces the chance of developing diabetes and the chance of weight gain.
Lessen the burden on your cardiovascular system and reduce heart-related diseases.
Quality sleep saves you from cancer. Your body continuously produces cancer cells as well as natural cancer kill cells. One night of 4 hour-sleep reduces the count of natural cancer cells by 70%.
Sleep makes you look younger. When you don’t get enough sleep, your body releases more of the stress hormone cortisol. In excess amounts, cortisol can break down skin collagen, the protein that keeps skin smooth and elastic.
Tips for sleeping better
With the frightening consequences of sleep-deprivation and immense benefits of adequate rest, you should not only try to allocate sufficient time for your slumber but also strive to increase the quality of it. Here are things that I have tried and proved to be effective in improving the quality of my sleep.
Allocate a sufficient amount of time for sleep
Refer to the National Sleep Foundation for the recommended amount of sleep per age. For adults, it is recommended to obtain at least 7 to 8 hours of sleep per night. Cognitive impairment can be measured when operating on or below 6 hours a night.
We have different phases in our sleep with different functions, often categorized into REM (rapid-eye-movement) sleep and NREM (non-REM) sleep. Different sleep states occurring at different times of night, but you can see from the figure that the majority of REM sleep occur close to 6 to 7 AM, right before we wake up. REM sleep has been associated with the quality of your sleep, and it is a stage associated with dreaming and memory consolidation (it is required both adequate REM and NREM sleep for memory consolidation).
Therefore, when you cut short your sleep from 8 hours to 7 or 6, even though you are only cutting 12.5 to 25% amount of your sleep, you are cutting more than an hour of REM sleep. In other words, by sleeping less 1 to 2 hours each night, you are reducing more than 67% of the quality of your sleep (we get about 90 minutes of REM sleep every night).
Reduce or remove caffeine and alcohol from your diet
Caffeine has been known to block REM sleep, an essential stage of sleep. Avoid caffeine consumption, either in the form of coffee, tea, or energy drink, in the afternoon or before you go to sleep. I recently removed caffeine from my daily diet after periods of daily consumption and saw my sleep quality improved by a large margin.
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Contrary to common belief, alcohol does not help you sleep better. Alcohol is a sedative substance, meaning that it will knock out your nervous system rather than helping it achieving natural sleep. You often feel tired after excessing consumption of alcohol the night before, but often don’t know why. Alcohol will fragment your sleep, meaning you will wake up for brief periods during the night, without recalling it the day after. That what makes you feel tired.
Use a smart alarm or smart lights
There are several things wrong with your phone’s alarm. First of all, the alarm will set off at the same time every day, often at a non-optimal time, waking you from your deep sleep. Secondly, a loud and abrupt alarm is harmful to your heart. Your heart rate will increase as a byproduct of the sudden sound. The effect is compounded when you repeatedly hit the snooze button.
There are two ways we can deal with this using technology. Firstly you can use an app called Sleep Cycle that acts as an alarm clock and a sleep monitor. Every night before going to sleep, you will plug in your phone, open the app, and lay it face down on the bed. Using the sensor of the phone, Sleep Cycle tracks your movement through the night and tries to approximate your quality of sleep. The app will also choose when your sleep is the lightest during your selected window to gently wake you up. Other alternatives to Sleep Cycle are products like Beddit by Apple or Sleep Tracking Mat by Withings, although they are more expensive options.
Another helpful solution is to use a smart light like the Phillips Hue or a smart alarm clock (also from Phillips) to simulate sunlight in the morning. Sunlight or light from a similar device is perceived by the retina and triggers the production of multiple chemicals in our brains that help us wake up in a natural way. You can feel it is harder to wake up in the winter when the sun rises much later than in the summer. With such devices, you can forego the need for a sound-based alarm clock altogether while waking up feeling energized.
Condition your body and room for quality sleep
We best fall and stay asleep when the physical condition is right. Temperature and humidity play an vital role in ensuring the quality of your sleep. You can use several devices to ensure the temperature is between 22 to 27 degrees, and the humidity is between 40 to 60%. Try to go to sleep every day at the same time, even on the weekend, and reserve the bad only for sleep and sex.
When we sleep, our heart rate slows, and our body cools down. You often here tricks like drinking a cup of hot milk or taking a warm bath to help fall asleep better. The science behind those tricks is when you do so, your body will slowly cool down to room temperature, thus simulating the condition for a good sleep. Also, make sure to block out any light and minimize the sound exposure during your sleep.
Reduce/remove technology before sleep
Through millions of years, human has relied on light to wake up and fall asleep. However, exposure to bright lights, especially blue light blocks the production of a hormone called cortisol, the help in the onset of sleep. The amount of cortisol in your brain will rise throughout the day, and you will feel sleepy when it reaches a certain threshold. Therefore, it is best for your sleep to reduce exposure to bright lights during the night, especially one hour before your sleep.
Modern devices have options to limit the emission of blue lights through your screens. You can schedule those settings to turn on automatically after sunsets. Try to have a screen-free hour before bed by reading a book, meditate, talking to your significant other.
Skip the sleeping pills
Sleeping pills, similar to alcohol, is a sedative method to knock out your nervous system. Using those pills will not help you in falling asleep in a natural way, and consumption of those pills has been linked with cancer.
When you are in bed for an extended time and cannot fall asleep, wake up, and do other activities such as reading a book. When you feel sleepy and tired, try to go to sleep again. If you experience insomnia, consult a doctor for treatments.
Dr. Walker said that human is the only species who deliberately deprive themselves of sleep for no apparent biological reason. Sadly in our society today, many people, especially leaders, pride themselves on the ability to survive with 4–5 hours of sleep.
If you take away one thing from this post, I hope it is this:
Sleep is a life-supporting function for human, and you are literally shorten your life by sleeping less.
I hope you learn something about sleep through this post. Sleep more and better to improve your learning and living longer.
This is my book review of Why we sleep by Dr. Matthew Walker, coupled with my 50 cents of personal advice. All credits go to the book and the following resources.