Anyone who knows we had an election problem in November knows that eating right and exercising regularly will help us live significantly longer and better. Conversely, poor diet (i.e., the stuff most people eat) and sloth (i.e., the nothing most people do) are significant predictors that our later years may be unnecessarily spent in impaired health or in a grave.
Medical science is just now learning that inadequate sleep may reduce the quality and/or quantity of our lives as surely and as much as bad diet or inadequate exercise does. Recent research repeatedly implicates long-term sleep debt as a likely factor in the U.S. epidemics of diabetes, obesity and certain cancers. Boasting about one's short sleep is becoming medically akin to bragging about eating lots of fatty foods, avoiding exercise, even driving drunk. Sleep deprivation is so prevalent that the National Institute of Mental Health suspects "very few adults in the industrialized world know the crystal-clear sensation of being completely rested", according to U.S. News & World Report.
We've discussed before how to sleep better; now it's time to discuss why we should sleep longer. And don't even ask: you do not get enough sleep. By the time we retire and start spending adequate time in bed, the declining quality of our sleep still denies us the quantity of sleep we need. Almost all those people who say they "do fine on six hours of sleep regularly" are deceiving themselves, according to emerging medical evidence.
How do you know whether you are sleep-deprived? That's easy: as a first test, you're breathing. More rigorous criteria say we don't get enough sleep if we sleep less than eight hours almost every night or get drowsy any time during the day or evening. In particular, if you can easily doze off in a dull meeting, in a warm church, in front of a 45 to zip Monday Night Football game, riding in the back seat, or in a deliberate ten-minute afternoon nap; if you need an alarm clock to wake up to go to work on a January Hump Day; if you are able to sleep late on weekend mornings; if you snore or snort while sleeping; even if you're merely past The Big Five-Oh -- it's quite likely you're sufficiently sleep-deprived to affect your performance, health, and longevity.
Most of us fit one or more of those molds. But so far we've lived just fine on 5-6-7 hours a day, haven't we?
No, we haven't. It's that simple. Hundreds of millions of people have missed test questions, made little and big mistakes at work and home, gotten sick or injured, and/or even shortened our lives just because we get insufficient sleep. Worse yet, we've violently killed hundreds of thousands of people by scrimping on sleep.
If that didn't wake you bolt upright, you're more sleep-deprived than most of us, or just skeptical. Let's dispel that skepticism with some old facts, new facts, and sleep research findings.
Sleep research isn't just about sawing logs; it's more like rocket science. It's about alpha, beta, and theta brain waves; REM sleep; extensive mental and physical performance tests; blood and brain chemistry; human physiology; and population health statistics. Sleep lab tests consistently show that most healthy people consistently wake up spontaneously after 8.25 hours of sleep once they've had many nights of unlimited sleep to erase any sleep debt. Both in sleep labs and in ancient historical records, people free to sleep long hours (by lack of electricity centuries ago, by design in modern studies) tend to sleep similar hours. Historical records loosely imply eightish hours; sleep lab subjects usually hit 8.25 hours.
Extensive research has revealed more than a dozen dramatic impacts of loss of sleep, or sleep deprivation. For adults, that is defined as anything less than a full eight solid hours every night. Research on kids establishes that grade-schoolers need 9 to 11 hours sleep every night, while teenagers may manage pretty well on 8-1/2 hours on weekdays if they catch up on weekends.
- Skipping just half an hour of the optimal sleep level (7.5 hours rather than 8 hours for adults) measurably impairs (by many forms of testing) our abilities to learn, solve problems, speak, write, react, endure stress, and get along with others.
- Our brains process, organize, and store new information long-term primarily while we sleep. Kids are being exposed to new facts and whole new concepts at an astounding pace, so adequate sleep during their formative (pre-school and school) years is vital to their development. Less than that may contribute to the increasing incidence of depression, automobile wrecks, and misdiagnosed hyperactivity and ADD.
- Losing an hour (getting just seven hours of sleep one night for adults) measurably impairs both our mental and physical abilities as much as two alcoholic drinks.
- Several studies have concluded that people who get sleepy during the day have worse health and higher mortality rates than well-rested people, possibly due to the observed and suspected effects of sleep loss on our immune systems.
- Recent research reveals chronic sleep loss may increase the risk of developing insulin resistance, diabetes, high blood pressure, coronary heart disease, stroke, and maybe cancer.
- Sleep loss probably also diminishes our secretion of growth hormone, leading to loss of muscle mass, which lowers our metabolism, which contributes to obesity, which helps kill hundreds of thousands of us every year. Those aren't mere statistics; each link can be explained by medical cause and effect analysis.
- In one well-respected, peer-reviewed study, healthy young men were allowed only four hours' sleep each night for a week (after a week of plenty of sleep). Within just a few days, their central nervous system activity, pancreatic insulin secretion, and glucose tolerance clearly demonstrated a classic pre-diabetic state. (I hope everyone knows that diabetes is not just a nuisance cured by pills or shots; it's a truly horrible disease if not caught early and managed very strictly.)
- In addition, those men's morning cortisol levels, which help energize our bodies each morning, matched the much lower levels of their grandparents.
- Sleep deprivation chemically induces carbohydrate cravings even when we're full, which piles on the calories and puts even more pressure on our growing diabetes problem.
- Rats robbed of all sleep die in two weeks from raging infections due to immune system suppression. Even moderate, short-term sleep loss measurably suppresses human immune systems significantly.
- Many different types of studies show that sleeping in light (from artificial sources or daylight) may increase our cancer risk because light entering our eyes even through closed eyelids decreases melatonin and increases estrogen releases. This is particularly suspected as a possible cause for the epidemic in breast cancer. Sleep in the dark.
- People awake for 19 consecutive hours (doesn't that sound like many pilots, drivers, students, surgeons, workaholics?) compare bumble-for-bumble with legally drunk drivers on performance and alertness tests. Inadequate sleep has been estimated to contribute to 100-200 thousand automobile wrecks every year.
- European population studies showed that longevity peaks with about eight hours of sleep, with adults who average less than eight hours or more than nine living shorter lives.
- We sleep less effectively as we age, so eight hours of sack time no longer equals eight hours of sleep. By our mid-50s our sleep inefficiency gets significant, and by the time we're 60 the 50% reduction in our REM sleep produces dramatic changes in our bodies.
- Caffeine and/or naps of the proper duration (either over two hours or under 45 minutes) help alertness, but do not avert the health problems attributed to sleep loss.
- Machismo does not cancel any of the effects of chronic sleep loss. Many thousands of super-moms and super-dads will not live to see the long-term results of their super-efforts; millions more will see them through diminished capacity.
It's surprising how uniform the eight-hour adult need is, but there are, of course, exceptions, ranging from seven to ten hours. Sadly for overachievers, the latter exception is more common than the former. Probably the best way to determine your own sleep needs is to take a two-week vacation with sleep as a top priority - an idyllic tropical isle or a B&B in Keokuk, not a whirlwind tour or a sports marathon, and sans cell phone or fax machine. After many days of making up lost sleep, you're likely to settle in on a fairly consistent amount of sleep after which you awake with no alarm clock, refreshed, naturally. That's how much sleep you need every night to perform, feel, and live best. Most adults under 50 settle in at 8-1/4 hours.
Could it be we're allotted only so many hours awake between birth and death, that it's up to us to spread them out enough to enjoy them in clarity and vigor rather than burn them up early in a mental fog and diminished health?
Naaah, that's silly, isn't it?
Gee. D'ya think?
For more information, see www.nhlbi.nih.gov/about/ncsdr/ and www.sleepfoundation.org.