INTRODUCTION

The Power of Sleep

We know sleep restores and renews, but only if you get enough of it

BY ALICE PARK

When our heads hit the pillow every night, we tend to think we’re surrendering. Not just to exhaustion, though there is that. We’re also surrendering our mind, taking leave of our focus on sensory cues, like noise and smell and blinking lights. It’s as if we’re powering ourselves down as we do the electronics at our bedside—going idle for a while, only to spring back into action when the alarm blasts hours later.

That’s what we think is happening. But as scientists are now revealing, that couldn’t be further from the truth. In fact, when the lights go out, our brains start working—but in an altogether different way from when we’re awake.

Scientists are just beginning to piece together the larger picture. Getting more and better-quality sleep each night can improve concentration, sharpen planning and memory skills and maintain the fat-burning systems that regulate our weight. If every one of us slept as much as we’re supposed to, we’d all be lighter, less prone to developing Type 2 diabetes and most likely better equipped to battle depression and anxiety. We might even lower our risk of Alzheimer’s disease, osteoporosis and cancer.

The trouble is, sleep works only if we get enough of it. Which is why, after long treating rest as a good-if-you-can-get-it obligation, scientists are making the case that it matters much more than we think. They’re not alone in sounding the alarm. With up to 70 million of us not getting a good night’s sleep on a regular basis, the Centers for Disease Control and Prevention considers insufficient sleep a public-health problem.

It would seem to be a problem with a simple solution. And yet, despite how great we know we feel after a night’s rest—and putting aside what we now know about sleep’s importance—we stubbornly refuse to swallow our medicine, pushing off bedtime and thinking that feeling a little drowsy during the day is an annoying but harmless consequence. It’s not.

“We all want to push the system, to get the most out of our lives, and sleep gets in the way,” says Sigrid Veasey, a leading sleep researcher and a professor of medicine at Perelman School of Medicine at the University of Pennsylvania. “But we need to know how far we can really push that system and get away with it.” What’s needed is a rebranding of sleep that strips away any hint of its being on the sidelines of our health.

As it is, sleep is so undervalued that getting by on fewer hours has become a badge of honor. Plus, we live in a culture that caters to the late-nighter, from 24-hour grocery stores to online shopping sites that never close. It’s no surprise, then, that one third of American adults don’t get the recommended seven to nine hours of shut-eye every night.

Making things trickier is the fact that we are unaware of the toll sleep deprivation takes on us. Studies consistently show that people who sleep less than eight hours a night don’t perform as well on concentration and memory tests but report feeling no deficits in their thinking skills. That just perpetuates the tendency to dismiss sleep and its critical role in everything from our mental faculties to our metabolic health.

The ideal is to reset the body’s natural sleep-wake cycle, a matter of training our bodies to sleep similar amounts every night and wake up at roughly the same time each day. To accomplish that is to consider sleep a must—not a luxury.

“We now know that there is a lasting price to pay for sleep loss,” says Veasey. “We used to think that if you don’t sleep enough, you can sleep more and you’ll be fine tomorrow. We now know if you push the system enough, that’s simply not true.”

This is why researchers hope their new discoveries will change once and for all the way we think about—and prioritize—our slumbers. The good news, as you will see in the chapters of this book, is that as we learn more about the intimate connections between our minds and bodies and our need for sleep, the better we will be able to address one of modern society’s most pressing health issues.