Sleep has been a big mystery for long, as it has been unclear what purpose it serves, and why natural selection did not weed it out. After all, in earlier times, the period of sleep must have been one of considerable danger for humans (and even now for many animals and birds). And yet, sleep is a common requirement across the animal kingdom as well. In fact, birds and some sea creatures have the remarkable ability to sleep half a brain at a time.
Matthew Walker is a sleep scientist and does an exceptional job in this book of explaining what sleep achieves for us. In fact, sleep deprivation is extremely dangerous and there is not enough awareness of this. Modern lifestyle has dealt a blow to both our duration and quality of sleep, and the effects are already quite apparent.
While sleep has not completely revealed all its mysteries to us, a lot is now known after painstaking research over several years. Our sleep shuffles between NREM, Light and REM sleep – and all of them have their purpose. NREM sleep fortifies our memory helping in longer term recall, while REM sleep & dreams lend emotional balance and help us get to the big picture. The book discusses a large number of experiments detailing what happens when we skip sleep. Depending on the sleep cycle and the quantum of deprivation, the ill effects are nothing short of disastrous – lower immunity, failing memory, loss of emotional balance, pre-disposition to serious diseases such as diabetes, dementia and even cancer. Getting adequate sleep (~8 hours) on the other hand makes people more creative & productive other than being healthy.
Somehow, our cultures today do not emphasise the importance of sleep, as much as we do exercise and diet. So much so, that sleeping less is mistakenly regarded as a confirmation of working hard and being more ambitious. The assumption that each of us can do with varying periods of sleep is largely a myth as well. While a genetic mutation allows a few to function effectively with around 6 hours of sleep, this is extremely rare. Almost all of us do need ~8 hours of sleep. There are tips on improving sleep quantity as well as quality all through the book, such as regulating caffeine in the later part of the day.
Most of us are guilty of not according sleep the importance it deserves, and this book is an eye opener. This is a book everyone should read. There are very important points of note for individuals, educational institutions, hospitals, organisations and even governments.
Amazing book. Read it, skip a few chapters and see how much we are killing ourselves over sleeping less. I changed my ukg going son's schedule after reading this book and I have never seen him being so active and healthy and eating food willingly. Read it along with 'The Circadian Code' by Dr. Sachin Pandta and one can change a lot of things going wrong in terms of health and weight!!
Book Review : Why We Sleep by Matthew Walker (Penguin Books)
TLDR : In depth treatment of Sleep, its reasons, its types and its impact on individual and society lucidly explained : 5/5
As a person who has suffered from sleep related problems for a decade and been on all variety of sleeping pills (quietapine, alprozolam, ambien) , this book is probably very pertinent to me in more ways than one although it tackles a much wider swathe of issues related to sleep.
The book first talks about technical aspects of sleep physiology like circadian rhythm, suprachiasmatic nucleus, melatonin, adenosine, polyphasic sleep, hypothalamus and thalamus which operate on sleep in disconnected pathways. It talks about the effect of caffeine, nicotine and alcohol on sleep. The book then delves deeply into the type of sleep like REM and NREM and the role of sleep spindles. Further, it highlights the different types of sleep in babies, adolescents, young adults and old people which is very interesting. The chapter on sleep across different animals is an eyeopener. The most interesting explanation of NREM sleep to solidify experiences and REM sleep to enhance problem solving and creativity via dreaming is very motivating. A surprising thing is that some people called lucid dreamers have been scientifically proven to control their dreams. All his claims are linked to fabulous research studies which make you wonder about the creativity of researchers. The chapter on the scientific basis of dreaming and emotional tuning via dreams is contrasted with the unscientific Freudian perspective.
Further chapters in book link sleep deprivation to cancer, immune diseases, testosterone and testes length reduction (take note!) as well as psychiatric problems. He busts myth that people can "sleep off" their sleep debt and that once you lose sleep it can affect you for a long time.
One chapter then deals with sleep disorders like insomina, narcolepsy and sleep apnea and the reasons for the same. Further chapters also deal with electronics, bad work policies, night lighting, room temperature control and sadistic alarm clock designs that add to sleep deprivation woes. A chapter then talks about making schools start late in the day so that children can sleep properly and boost their health and IQ as well as more sleep time for Government and Medical professionals. An important chapter advises against sleep pills and recommends CBT-i (recommended by USAs National Sleep Association). I downloaded an Android App immediately.
One shocking statistic is about the amount of lives lost due to sleep deprived driving (more than even drunken driving) and the author asks for policies to combat the same.
The last chapter talks about ideas in individual, educational, technological and social planes for a new vision of sleep.
I assure you if you read the book you WILL sleep 8-9 hours a day and will be disabused of all the myths you have
Humans have basic drives like To eat, to drink, to reproduce and to sleep. We spend 33 percent of our time sleeping. Evolution wise, why it is important was unknown. Sleep is such an important thing to know..Author Matthew Walker makes the subject accessible through this book.
The book 4 parts. First one address sleep rhythm, generation, quantity, process, and sleep changes during our lifespan. Second part is about why we should sleep?, its benefit and harms of not sleeping well Third part is about the dreams. How and Why? Fourth part is about the effects of technology and our modern lifestyle on our sleep.
The book is very well written, without loosing the scientific details. This is going to be an important reference book on sleep at least for few decades. Worth reading to understand the importance of sleep.