Emily's Reviews > Why We Sleep: Unlocking the Power of Sleep and Dreams

For once, I actually mean five stars in the sense of "everybody should read this book." This book is highly readable but contains stunning information I'd never seen anywhere else (and includes numerous references to serious primary literature).

I was reminded (stay with me here) of ancient Egyptian funerary practices. After carefully embalming organs like the heart and liver, and placing them in canopic jars, the Egyptians pulled the brain out with a hook and threw it away, because they didn't really know what it was for. This is how most modern people approach sleep. We know it must be sort of important, because why else would it be there, but we're quite foggy on the specifics and tend to give it short shrift. At worst, we see it as an "annoying and enfeebling" obstacle to other uses of our time.

Some standout topics here: your natural day/night pattern and the buildup of a chemical called adenosine in your brain that makes you sleepy, which contribute independently to your sleep cycle; and how caffeine and jetlag get you off your rhythm. (This was particularly interesting to me because I read this on a long flight. I never sleep on flights to Europe and this book explains why: I'm not sleep deprived enough to have excess adenosine to make me sleepy, plus it doesn't feel like nighttime yet when we depart. So my brain isn't interested in sleeping. When I arrive, my goal is to stay awake until 9pm and at first, it's easy. That's the "day" part of the circadian rhythm giving me a bit of a boost. But soon, that fades away and the extra adenosine comes crashing down.) The role of sleep in processing memories and new information: sorting out what's important, solidifying newly gained understanding, and turning traumatic experiences into bearable memories. How all creatures sleep, but in different ways that make the brain-repairing effects of sleep compatible with their environments. Some things that we think aid sleep, like alcohol and sleeping pills, are only useful if your goal is to lie inert in bed; they don't lead to true, restorative sleep.

Oh, and the doctor who developed the system for medical residents, and insisted that long shifts and little sleep were essential training, was a big-time cocaine addict.

There's some genuinely frightening information here as well. Sleep deficits cannot be made up (sleeping in on the weekends doesn't help) and lead to shorter lifespans. Lack of sleep contributes to Alzheimer's disease, mental illness, and cancer. (The WHO categorizes night shift work as a probable carcinogen.) Drowsy driving is more common than drunk driving and more dangerous. We may be seriously harming the country's teens by forcing them to wake up and go to high school at an hour so inimical to the circadian rhythm of that age group.

I already follow the author's advice about "sleep hygiene" so I was mostly attuned to the scientific information and arguments here about social ills. Many people in my sleep-deprived cohort may be genuinely alarmed to read this book. But that doesn't mean you shouldn't! I read so many nonfiction books with titles like this one that are ho-hum--but this one's a humdinger.

Review copy received from Edelweiss.