How much sleep in enough? There is no one right answer, despite what you might have been told time and again about getting eight hours per night. Well, there are some wrong answers, including anyone who insists four to five hours of slumber is enough.
The National Sleep Foundation, which conducts yearly surveys on Americans’ sleep habits and serves as clearinghouse for researcher and consumer groups, suggests a healthy total for adults is seven to nine hours nightly, while teens are better off with 8.5 to 9.5 and five- to 12-year-olds need somewhere between nine and 11 hours. Notice there is a range for each age category; even babies are deemed to require 14 to 18 hours.
A number of studies point to seven to eight hours as optimal for the health of adults. Yet some research makes a case for getting eight to nine. For example, a University of Connecticut School of Medicine study of 12,000 women showed that who slept nine hours per night on average had a 33 percent less chance of developing breast cancer as women who slept less.
Interestingly, scientists have debated whether it is sleep itself or shutting down exposure to light that helps prevent breast cancer. There is a theory that too much exposure to artificial light at night lowers a woman’s melatonin hormone levels and in turn invites aggressive cancer cells to multiply. This nighttime light exposure is validated by research indicating women who work second or third shifts are more prone to breast cancer than females who work a usual workday.
While getting enough sleep seems to be more health bromide than cutting-edge information, the opposite is true. Researchers has discovered compelling evidence in recent years that sleep not only makes us feel, well, less sleepy, but it also restores mood through a documented modality of slowing down brain waves and plays a vital role in helping us remember things and reinforce what we learned during the previous day.
About 80 percent of our sleep is slow-wave. So getting enough sleep translates to getting enough slow-wave restoration of our emotional and mental capacities. Cheating yourself on sleep (less than six is compromising; less than four is damaging) leads to a lack of slow-wave recuperation. University of Wisconsin researcher Giulio Tononi has discovered that sleep-deprived individuals have larger and more frequent slow waves when they finally do get a good night’s rest when compared to people who sleep seven to eight hours daily. In effect, the sleep-deprived person’s body is attempting to catch up on the slow-wave count.
During our waking hours, Tononi says people “observe and learn much more than you think.” Getting enough sleep at night supports our brains to collate and store all of things that leave a “trace” in our days.
Bob Condor blogs for Alternative Health Journal every Monday, Tuesday, Thursday, Friday and Saturday. He says 6.5 hours is about the shortest night’s sleep in which he feels fully rested—especially if he can get a 20-minute nap during the day. For more about napping, see Saturday Oct. 25’s final post of Sleep Power Week.