Why We Sleep: Unlocking the Power of Sleep and Dreams

A New Book by Matthew Walker; reviewed by Yasmin Anwar

Scientists have discovered a revolutionary new treatment that makes you live longer. It enhances your memory, makes you more attractive. It keeps you slim and lowers food cravings. It protects you from cancer and dementia. It wards off colds and flu. It lowers your risk of heart attacks and stroke, not to mention diabetes. You’ll even feel happier, less depressed, and less anxious. Are you interested?

“Why We Sleep,” is a book on a mission. Walker is in love with sleep and wants us to fall in love with sleep, too. It is urgent for him. He makes the argument, persuasively, that we are in the midst of a “silent sleep loss epidemic” that poses “the greatest public health challenge we face in the 21st century.”

Matthew Walker presides over Berkeley’s Sleep and Neuroimaging Lab, and has spent the last 20 years working to understand the restorative powers of sleep. “Sleep is the single most effective thing we can do to reset our brain and body health each day.”

A healthy night’s sleep lasts about eight hours and is divided between REM (rapid-eye movement) sleep, in which the brain is as active as it is when its owner is awake, and NREM (non-REM) sleep. NREM sleep, is crucial to memory retention, and to acquiring and refining our motor skills. REM sleep plays a role in our abilities to overcome negative feelings, read other people’s emotions and solve problems.

The last 100-odd years of industrialization, urbanization and purported progress have been hell on sleep. It really is true that you’ll have a harder time falling asleep after reading a book on an LED device than you will after reading one printed on old-fashioned paper; the blue light emitted by an iPad suppresses your brain’s natural release of melatonin, the hormone that induces sleepiness, by over 50 percent. Adults aged 45 and older who get fewer than six hours of sleep a night are 200 percent more likely to suffer a heart attack or a stroke than those who get their full sleep allotment.

In terms of our natural sleeping tendencies, people can be divided into two broad groups, or “chronotypes”: morning larks and night owls. Each group operates along different circadian lines, and there is pretty much nothing owls can do to become larks – which is tough luck, because work and school scheduling overwhelmingly favor early risers. Owls are often forced, he writes, “to burn the proverbial candle at both ends. Greater ill health caused by a lack of sleep therefore befalls owls, including higher rates of depression, anxiety, diabetes, cancer, heart attack and stroke.”

Basically, if you’re regularly clocking in at under seven hours a night, you’re doing yourself a disservice as grave as that of regularly smoking or drinking to excess.

Walker’s title is misleading, it suggests that there might be only one reason why we sleep. Sleep as a panacea for a bewildering array of conditions that would otherwise cause the slow deterioration of body and mind.

Walker’s Tips for Improving your Sleep:

  • Go to bed and wake up at the same time every day, even after a bad night’s sleep or on the weekend.
  • Keep your bedroom temperature cool; about 65 degrees Fahrenheit is optimal for cooling your body towards sleep. Wear socks if your feet are cold.
  • An hour before bedtime, dim the lights and turn off all screens. Blackout curtains are helpful.
  • If you can’t sleep, get out of bed and do something quiet and relaxing until the urge to sleep returns. Then go back to bed.
  • Avoid caffeine after 1 p.m. and never go to bed tipsy. Alcohol is a sedative and sedation is not sleep. It also blocks your REM dream sleep, an important part of the sleep cycle.

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