It’s been my whole life time (exaggerated) since I last understood the importance of sleep. That is. Study, gaming, binge watching tv series, doing personal projects, et cetera during the evening time until way past midnight have been what I believed as the way to efficiently spent time.
My daily 5-6 hours of sleep “felt sufficient” so far. I power nap in the afternoon for 15 minutes – not everyday but quite often. Often I thought I felt unsatisfied at the end of the day (literally) when bedtime is calling. I still wanted to continue to do what I love but whatever I did it was simply a procrastination of my sleep time. Nothing I continued doing before bed (to efficiently use time and be productive) were fruitful. It just delayed my sleep time. One AM, 2 AM, sounded like normal sleep time for me.
It was until I felt the cumulative fatigue is taking a toll. I didn’t feel as optimal as when I was young, always gloomy, micro-sleeping (for real) through out the day time, slow at learning what I am passionate to learn, and easily get tired for doing nothing. Am I getting old? My blood pressure is still high since I last visited my doctor 2 years ago. Bleh.
I felt that something needs to be done. First instinct was let me try to sleep more. I was probably right. And that was before I saw this book cover posted by a colleague on her social media. Why We Sleep by Matthew Walker. So, I felt like “hey this is probably what I need to convince myself with good sleep. Maybe it has good methods to help me. Or at least scientifically convince me.” It has. It took me a while to finish reading it. Anyway, read on.
Matthew Walker starts the book with a broad question that has scientist puzzled by this interesting feature that most of us humans and animals have: sleep. Why do we do it. Why do we need it. What’s its role. And why there is alien abduction happening. Yes, you read it right. Alien abduction. It is explained in this book. (You have to really read the book to understand this one though.) In this book, he points out the health trinity that I too have always believed in: diet, exercise, and sleep as the essence of health and long/healthy life.
I usually do not write brief summary about a book I read, but for this one I feel compelled share it. It is something we can start fixing independently while also opening our mind into some surprising findings that should help us make better informed decision about sleeping and get the best out of it. We all do sleep, don’t we? I put up some (sort of) summaries that I feel important for myself. I do hope you pick up the book and read it for yourself. I’m really sure it is very beneficial and reformative.
Circadian Clock and Melatonin
Jumping in to how body (brain!) works with regards to how we track the sun, in 1729, French geophysicist Jean-Jacques d’Ortous de Mairan discovered that plants too generate their own internal time. This is known as circadian rhythm. We all have circadian clock that we unconsciously keep track of the daytime and night. Each of us has our own circadian clock. A 24-hour cycle tracker internal rhythm which keep us from/into sleepiness cycle. The start and end of the “clock” may vary from individual to another. But amazingly the clocks are pretty accurate. Suprachiasmatic nucleus is part of the brain cells that helps govern the ‘clock’. It is a tiny compound of 20,000 cells. One of the signs it creates is the cycle of body temperature throughout the day. Walker suggests that there are about 40% people who are “morning types” while 30% are of “evening types” (the night owls). Hence, being a night owl is not a choice. “They are bound to a delayed schedule by unavoidable DNA hardwiring”. Mine is probably early bird.
This circadian rhythm is what signals our body to release melatonin at specific time period (e.g., when the day is dark). And that is when we (naturally should) feel sleepy.
So, what happens when we sleep?
All animals sleep, including some of those of multi cells microorganisms. While the amount of sleep needed by them varies. The reason of sleep length variations is not determined by physical size of the living being. The author mentions a complex hybrid of factors: dietary type, social behaviour, metabolic rate, and the complexity of the nervous system.
Sleep has a few stages, but the author mentions two crucial sleep stages namely REM (Rapid-eye movement), NREM (non-REM) also known as ‘deep’ sleep. They have different roles. Walker’s writing emphasizes on the essential need of quality REM and NREM sleeps.
During NREM sleep our brains generate certain slow-wave to “sweep” across our neurons and perform the miracle of intelligent essentials: transferring of data from our hippocampus section of the brain (where we temporarily store the learning and memory we did the day before) into the long term storage, the cortex. The brain will then free up our hippocampus for next session of learning and memory. This is a slow process and we all need quality and quantity of NREM sleep for this to work. In other words, this stage of sleep helps us build long term memory. In this stage of sleep we don’t dream.
The other critical role of NREM sleep is that our brain also processes the information of learning and memory of the other type, such as motor skills. For example, skills such as swimming, riding bikes, playing musical instruments and anything related to “muscle” memory. During NREM sleep our brain also transfer this learning fact and memory from hippocampus to hypothalamus area where it’s much closer to our body motor control nerves. Hence, the “muscle” memory. “Practice does not make perfect. It is practice, followed by a night of sleep, that leads to perfection” says Walker. If we sleep at 11pm, this process of NREM sleep happens around 5-7am.
The other type of sleep, REM sleep, has different crucial role for us:
- REM sleep exquisitely re-calibrates and fine-tunes the emotional circuits of the human brain. This is one reason why we feel groggy if we don’t have enough sleep.
- REM sleep fuel creativity. Exactly the reason why we dream. Details in the book.
Walker explains that being in REM sleep is almost exactly the same as being awake, except that we lost control over (most of) our body muscles. It is intentionally done by our brain.
In short, numerous functions of the brain are restored by, and depend upon, sleep.
Who Needs Sleep?
Knowing that the role of sleeps to us is crucial and our brain performs some (slow) process for it requires quality and quantity. Adults need as much sleep as the young. We that have transition into biphastic sleep mode (that is two cycles of sleep: at night and nap at noon) will require about 8 hours of sleep at night regardless of how old we are – it is a wrong disbelieve that we need less sleep at old age (e.g., after 60). Sleeping on time is important – the author explains in great detail about this when talking about our circadian rhythm.
The other revelation I got from reading this book is that poor sleep is strongly linked to many diseases such as Alzheimer, high blood pressure (see my case above!), heart disease and even cancer. Sleep deprivation is also strongly linked to reduced lifespan and impairment of our immune system!
Quoting the book directly: “not all medical problems of aging are attributable to poor sleep. But far more of our age-related physical and mental health ailments are related to sleep impairment than either we, or many doctors, truly realize or treat seriously. Once again, I urge an elderly individual who may be concerned about their sleep not to seek a sleeping pill prescription. Instead, I recommend you first explore the effective and scientifically proven non-pharmacological interventions that a doctor who is board certified in sleep medicine can provide”.
“Beyond scientific curiosity, it is also a pressing clinical issue for the elderly, considering the importance of deep sleep for learning and memory, not to mention all branches of bodily health, from cardiovascular and respiratory, to metabolic, energy balance, and immune function.” I am not scientist, but I totally agree.
The Dangers of Sleep Deprivation
Matthew Walker explains that depriving ourselves of sleep even for a couple of hours can have immediate consequence. Well, we may not know we are sleep deprived but it shouldn’t be taken lightly. The effect of having not enough sleep at night (e.g. 7-8 hours) can be immediately observed. The author goes into lengthy explanation of how this data is collected in many experiments. Again, read the book for how all these scientific researches are performed.
Personally, to me, the most striking fact that Walker presents in the book is driving drowsy. If you have followed me for a while you will know that I’m very concern about the traffic accidents (I mean casualties!). Over a million deaths worldwide annually on something that I felt was preventable. That was what I thought before I read it on this book. And yeah I am not surprised to see a lengthy mention of deep deprivation link to traffic accidents. The author concludes that driving drowsy is equally as dangerous as drunk driving. His experiment on sleep deprivation, even for a small amount of lost sleep, yields a link with lost of vehicle control. Sadly, this is something that probably authority have to dive into more frequently as it is really preventable whilst currently has a very huge life impact.
Now I fear a long flight. Why? Because the pilot… never mind. Read the book. It also tells you where power nap comes from. And, do you know that doctors and medical staffs work in long-hour shifts? Dangerous! “Medical errors are the third-leading cause of death among Americans after heart attacks and cancer.” argues the author.
Walker suspects that there is a very strong connection of chronic sleep deprivation to Alzheimer disease. It is discussed in details in the book about how the mechanics of biochemical works in our brain when we are (chronically) sleep deprived which links to how we retain our memory and build the neuron pathways. I believe in this possible cause but I will not discuss it here.
The Other Stuffs
The book explains many other sleep deprivation related problems that we encounter in society and yet we are probably not well informed enough to make a change. The author explains some solutions to them. Including (but not only to) problems of sleep deprivation on school children having to go to school early in the morning, recovering patients having been disturbed by medical routines, and more.
It is also worth mentioning the false impression role of sleeping pills in treating insomnia. Walker suggests that sleeping pills do not help us sleep, instead they sedate us. We don’t get natural sleep from sleeping pills – see the explanation about NREM and REM sleep – and our brain doesn’t carry out its important duty during our sleep when we consume sleeping pills to help us sleep.
Oh yeah. There is a mention about one very rare insomnia-type disease called Narcolepsy. I am totally shocked to know that such diseases exists. This particular illness is genetic and affects how the brain could suddenly shutdown it’s connection to the patient’s motor muscles by our brain’s neruropeptides called orexin. Something called cataplexy. Similar to seizure happens when the disruption of motor muscles happens. But the patient doesn’t really experience seizure. Interestingly new to me, yet I feel sympathetic to whoever has it. My apology.
Conclusion
Anyway, we (adults) need 8 hours of sleep daily at the right time. Regardless of how old we are. Fix our sleep. Fix it now.
Get your book now (link to book depository). I borrowed e-book version from library.