The Health Benefits of Getting Enough Sleep

IT’S HARDER THAN ever nowadays for many people to get a good night’s sleep. For some, there is simply too much they want to do in a day, and they can ill afford the “down time” that sleep requires.

Many others — up to 40 million Americans, according to Institute of Medicine — have chronic sleep disorders that prevent them from getting all the rest they need. They may have trouble falling asleep or staying asleep, difficulties breathing while they sleep, or they may wake up before their bodies and minds are fully rested and refreshed.

As a result, on most days of the week many millions of Americans are soldiering on with too little sleep, often reviving themselves with caffeine. The cost to employers of so much daytime drowsiness — and the impaired work performance it causes — runs to about $150 billion per year, according to the IOM.

Insufficient sleep isn’t a new problem, but lately it has been getting worse. In 1942, a Gallup poll showed that American adults were sleeping an average of 7.6 hours per night with only 3 percent reporting fewer than six hours. By 2001 that average had dropped to just 6.7 hours, with 16 percent of adults reporting that they were getting less than six hours of sleep.

Most experts on sleep, like those at the Centers for Disease Control and Prevention, say adults should get seven to nine hours of sleep per night. Adolescents need at least eight and a half hours, and younger children need even more.

Until now, we who work in public health haven’t put nearly as much emphasis on the need for a full night’s snooze as we have on the need to eat a healthy diet, the need for sufficient exercise or the need to avoid tobacco.

But now it may be time for us all to pay a little more attention. There is a bevy of new medical evidence showing that sleeping well may be more essential for a healthy heart, brain and waistline than anyone had ever imagined.

Researchers in the Netherlands reported in July that getting sufficient sleep is a key factor in preventing cardiovascular diseases. After following nearly 15,000 Dutch adults aged 20 to 65 years for an average of 12 years, they found that those who regularly got seven or more hours of sleep per night were 22 percent less likely to develop cardiovascular disease, and about 43 percent less likely to die from it, compared to those who slept less.

When having seven or more hours of sleep was added to regular exercise, a healthy diet, moderate alcohol use and nonsmoking, the incidence of cardiovascular disease was lowered by 65 percent. The same combination of factors reduced fatalities by 83 percent, according to the report published in the European Journal of Preventive Cardiology.

The heart benefits of having sufficient sleep may stem in part from the advantage that sound sleep provides in controlling weight. This unhealthy link was confirmed under controlled laboratory conditions in a study published in July in the journal SLEEP by researchers at the University of Pennsylvania.

In this study, about 200 of the 225 healthy, non-obese subjects were randomly restricted to four hours of sleep starting at 4 a.m. for five consecutive nights, while the other subjects in the study got 10 hours of sleep per night. Participants had access to food at all times, and they did not exercise for the 18-day duration of the study. By the end of the study, those who had been deprived of a full night’s sleep had gained more weight after consuming significantly more calories.

Perhaps the most disquieting research on the importance of sound sleep emerged in 2012 at the Alzheimer’s Association International Conference in Vancouver, British Columbia. Researchers from Harvard University presented findings that linked disordered sleep in middle age and later life with subsequent development of memory difficulties or dementia.

The researchers conducted repeated cognitive evaluations on more than 15,000 retired female nurses age 70 years or older during a six-year period. The nurses had been queried about their usual sleep duration and sleep quality at two times in the past, in 1986 and in 2000.

Those nurses who in the past had either reported sleeping five hours a day or less, or nine hours a day or more, both tended now to show more cognitive decline than those who had been sleeping for about seven hours per day. In terms of brain function, having a history of too little or too much sleep was equivalent to two years of aging, the researchers said.

These studies are pointing to the same conclusion, proving what your mother and grandmother already knew: A full night of sound, restful sleep is good for your health. Here’s how to make the most of your chance at getting quality Zzzs every night:

• Try to get to bed and wake up at about the same time every day.

• Do your best to create a quiet, comfortable, calming space when you go to sleep.

• Exercise during the day will help you sleep, but avoid exercise immediately prior to bedtime.

• Avoid caffeinated beverages within eight hours of going to bed. Don’t eat a heavy meal just before you sleep, and don’t drink alcohol right before bedtime.

• Turn off electronic devices when it’s time for bed. If you need help falling asleep, engage in a quiet activity like reading something light and entertaining until you feel sleepy.

Make it a priority to give yourself the gift of a full night’s sleep. It will pay big dividends in your health.

Dr. Eberhart-Phillips is the former Marin County Public Health Officer.  He is a specialist in preventive medicine and the author of two books on emerging infectious diseases.