Getting a good night’s sleep is something most of us take for granted. It simply happens. Or, at least it used to! These days, a consecutive, full night of rest is only occasional. Maybe that’s why I was drawn to an interview featuring psychiatrist Tom Wehr at the National Institute of Health. Dr. Wehr conducted a very interesting study on sleep. Young, healthy individuals were required to spend up to twelve hours per day in bed for almost a month. After several days, their sleep patterns started to stabilize at about eight hours of sleep per night. But the subjects were young and healthy, and oftentimes young people need more sleep than middle-aged or older adults. In addition, the subjects spent a tremendous amount of time in bed, which may have lead them to sleep longer. What would happen if this experiment were done with older individuals? Would we all start sleeping eight or more hours, even me?

I think I’d go plain crazy. As I get older, sleep is becoming more and more elusive. (Well, not compared to when I had a newborn and a toddler, which was no doubt the most tortuous sleep deprived period of my life.) As it turns out, historically, people would sleep in two bouts. The first bout was called first sleep, or dead sleep, and the second bout was called morning sleep. And the period in between? This was referred to as watch, or watching. Remember, this is when people lived from sun to sun, as a winter day could bring 14 hours of darkness. Clearly our environment is very different, with many of us in bed with a limited amount of time. This makes me curious about what the “real” recommendation of amount of sleep for those of us who are “middle aged” – meaning not twenty year olds, but not eighty year olds either.

What Dr. Wehr and others have found is that sleep tends to get more fragile as we age. Another physician, Dr. Mary Carskadon (Director of Chronobiology from Brown University who runs www.sleep for science) explains that brain waves loose their peaks as we age. Those peaks are what protects us from disturbances in the environment. (Clearly, my peaks are resembling small hills at this point.) But what can we do about it, and should we even care? There are sleep “strategies,” like naps, siestas, or restricting the number of hours in bed in order to encourage efficient sleep. Does this mean that as we age we should still aim for that magical number of eight hours of sleep per night?

Fortunately for me, the answer is no, depending on what study you read. I like the study by Dr. Daniel Kripke and his colleagues at the University of California at San Diego. (See http://health.ucsd.edu/healthinfo/videos/sleep.html for more information.) To summarize, over a million adults of all ages were studied in order to research the relationship between sleep duration and mortality. The results showed that people who slept seven hours per night had the lowest death rates over a six year period, while people who slept eight or more hours had a greater risk of dying over the same period. In fact, the greater the sleep duration beyond eight hours per night, the greater the death rate.

So what do I walk away with here? To relax. Sleep patterns tend to change as we age. When it’s 2:00a.m. and I am wide awake, I may just think about the two bouts of sleep that Colonial Americans experienced. From here on in, I’ll listen to my own body, and recognize that sleep, just like diet, is about moderation. Too little or too much may, in fact, be unhealthy.