For a long time, the questions of why we sleep and dream remained unanswered — or answered speculatively in ways that proved without merit. One presumes the reasons are potent because there seems to be little evolutionary advantage in spending a third of one’s life unconscious of one’s environs and paralyzed (literally in REM sleep, but for all intents and purposes in NREM sleep as one can’t respond to changes in the environment without some part of one’s brain taking note of said changes.) The good news is that Matthew Walker’s book offers insight into what scientists have learned about why we sleep, why we dream, why we become so dysfunctional without doing both, and what it is about modern life and its technologies that has created an apparent crisis of sleep loss. Walker goes beyond the science to discuss what individuals and institutions can do to reduce the harmful effects of sleep deprivation.
The downside of this book is that it’s a bit alarmist, and in contrast to many books of this nature one doesn’t get a good indication of the quality of studies reported. Some pretty brazen claims are made and the reader doesn’t necessarily know if they are preliminary and unvalidated or if they are well established. Here, I’m speaking about the studies that try to isolate out the effect of sleep loss versus all other factors (which is a notoriously messy affair,) and not so much studies that report on the physiological effects of sleep and sleep loss (which I see less reason to not take at face value.) At any rate, any reader who doesn’t fall asleep as soon as his head hits the pillow and sleep straight through 7 hours and fifty-five minutes — waking 5 minutes before the alarm — is likely to feel doomed if they take this book too seriously. And if you ever engaged in shift-work (as I have) or had an intense travel schedule, you are likely to feel that your life is permanently and irretrievably wrecked.
I know this is a book on sleep, but I think it went a little too far in marginalizing all other elements of health and well-being. Walker said that he used to tell people that sleep, nutrition, and exercise were the trifecta of good health, but he ultimately concluded that sleep was more important because diet and exercise were adversely impacted by sleep loss. I don’t disagree that diet and exercise are harmed by sleep loss, but – of course – sleep quality is harmed by lack of proper diet and exercise as well. The author later discusses research confirming this two-way street. I, therefore, have no idea why he changed his initial balanced and reasonable view with one that suggests sleep is the 800-pound gorilla of health and well-being.
The book’s 16 chapters are divided into four parts. Part I (Ch. 1 – 5) lays out what sleep is, how rhythms of sleep are established / disrupted, how much sleep one needs, and how one’s sleep needs change throughout the course of one’s life. Part II (Ch. 6 – 8) explores the benefits of sleeping as well as describing the nature of the damage caused by lack of sufficient sleep. Part III (Ch. 9 – 11) shifts the focus to dreams, and delves into what they appear to do for us. The final part (Ch. 12 – 16) investigates the many ways in which modern life disrupts sleep from blue light in LED’s to arbitrary school and work schedules to cures that are worse than the ill (i.e. sleeping pills.)
There is an appendix that summarizes twelve key changes that an individual can make to get more and better sleep. There are graphics throughout the book, mostly line-drawn graphs to provide visual clarity of the ideas under discussion.
I found this book interesting and informative. I would recommend it for anyone interested in the science of sleep or how they might sleep better, with the exception of anyone who has anxiety about the state of his or her health and well-being. While I understand that Dr. Walker wants to drive changes regarding views and policies that have been wrong-headed or deleterious regarding sleep, I feel he went too far toward suggesting the sky is falling for anyone who gets less than a perfect night’s sleep every night of his life.