In praise of a good night’s sleep

by Yule Heibel on July 24, 2005

For all the 24/7s out there running on empty: the July/August issue of Harvard Magazine features an interesting article by Craig Lambert, Deep into sleep, which is all about …sleep. If you’re short-changing yourself on sleep, you might (will?) pay for it in ill-health down the road:

When people make the unlikely claim that they get by on four hours of sleep per night, [associate professor of psychiatry Robert] Stickgold often asks if they worry about what they are losing. “You get a blank look,” he says. “They think that sleep is wasted time.” But sleep is not merely “down time” between episodes of being alive. Within an evolutionary framework, the simple fact that we spend about a third of our lives asleep suggests that sleep is more than a necessary evil. Much transpires while we are asleep, and the question is no longer whether sleep does something, but exactly what it does. Lack of sleep may be related to obesity, diabetes, immune-system dysfunction, and many illnesses, as well as to safety issues such as car accidents and medical errors, plus impaired job performance and productivity in many other activities. [More…]

The article characterises many people’s sleeping habits as akin to a sort of “sleep bulimia”: we “make up” sleep deprivation at “convenient” times, but short-change ourselves at other times. It seems like a “good idea” to get by on very little sleep during the week, making it up on weekends, for example. But just as bulimiacs didn’t know what eating disorders could do to health on a systemic level, it seemed like a great idea to load up on food and then throw it up to keep the weight off — until we learned what the long-term health damage was, that is. Today, we’re starting to learn what the long-term health damage is of “gorging” on sleep-deprivation, whether it’s followed by weekend “make ups” or not.

Not only how much sleep, but when people sleep has changed. In the United States, six to eight million shift workers toil regularly at night, disrupting sleep patterns in ways that are not necessarily amenable to adaptation. Many people get only five hours per night during the week and then try to catch up by logging nine hours nightly on weekends. “You can make up for acute sleep deprivation,” says David P. White, McGinness professor of sleep medicine and director of the sleep disorders program at Brigham and Women’s Hospital. “But we don’t know what happens when people are chronically sleep-deprived over years.”

“We are living in the middle of history’s greatest experiment in sleep deprivation and we are all a part of that experiment,” says Stickgold. “It’s not inconceivable to me that we will discover that there are major social, economic, and health consequences to that experiment. Sleep deprivation doesn’t have any good side effects.”


Sleeping well helps keep you alive longer. Among humans, death from all causes is lowest among adults who get seven to eight hours of sleep nightly, and significantly higher among those who sleep less than seven or more than nine hours. (“Those who sleep more than nine hours have something wrong with them that may be causing the heavy sleep, and leads to their demise,” White notes. “It is not the sleep itself that is harmful.”) [More…]

Not enough sleep over time compromises a person’s immune system, leaving them vulnerable to all kinds of auto-immune disorders — and that covers a huge category of health problems.

The article elaborates on some evolutionary speculations as to why we aren’t designed to “catnap” throughout the day and night, instead benefitting from “consolidated sleep periods” of 7 or 8 hours at a stretch, even though we are trying to convince ourselves that we really aren’t subject to circadian rhythms. However:

The human species, or much of it, anyway, apparently is trying to become simultaneously nocturnal and diurnal. Society has been squeezing the window for restful sleep ever narrower. (Czeisler likes to quote colleague Thomas Roth of the Henry Ford Sleep Disorders Center in Detroit, on the minimal-sleep end of the spectrum. “The percentage of the population who need less than five hours of sleep per night, rounded to a whole number,” says Roth, “is zero.”) [More…]

At this point in medical research, according to Robert Stickgold, we don’t even know yet what it is that sleep does, for there are processes that happen only when we’re asleep.

Good night, I’m off to get some sleep…

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