Sleep Patterns

I was reading an interesting excerpt from Why We Sleep by Matthew Walker PhD about how our sleep patterns are the key to a much longer life. According to him, we are not sleeping the way our distant ancestors  did, the way Nature intended us to.

Walker states that in olden times, in hunter-gatherer societies, people enjoyed a biphasic sleep pattern, seven or eight hours in bed at night resulting in about seven hours of sleep , along with a 30-60 minute nap in the afternoon. Furthermore, the nightly slumbers usually began 2-3 hours after dusk, around 9pm and lasted until dawn. No doubt, this was because those early cultures did not have the benefit of electric light and even firelight represented a drain on scarce resources.

Nowadays, in the post industrial age, we have been forced into a mono-phasic sleep pattern in which we sleep  for less than seven hours a night. Typically, this begins late at night though we still wake up quite early. And ,of course, modern office hours don’t permit the taking of an afternoon nap.

In support of his argument, that this enforced monophasic pattern is harmful to health, Walker points to a study of people who had to switch from a biphasic to a monophasic sleep pattern. Previously, they had office hours that incorporated an afternoon siesta but  were then forced to fall in line with the rest of the world and work regular 9 to 5 shifts. This study showed that over 6 years, these people suffered a 37% increased risk of death due to heart disease. Another statistic: People on the Greek island of Ikaria were four times as likely  to reach the age of ninety as Americans did.

When I began to read this excerpt, I did so with an open mind, but the more I read the more my doubts began to mount. Firstly, even if a biphasic sleep pattern is ” natural”, most of us never enjoyed it once we started our working lives. So how could we feel deprived of something we never had? Just as some factory workers, medical staff and others  get used to working the night shift, is it not likely that a monophasic pattern is becomes the new standard for us? In any case, what choice do we have? There is no way we will be able to shift back to a biphasic pattern. Even nations that enjoyed a siesta are switching to a 9 to 5 schedule.

As for those people in Ikaria who have a four times greater chance of living to the age of ninety, can this be attributed solely to their biphasic sleep pattern? These people are mostly farmers or shepherds; they work hard, live in an unpolluted environment,  eat a healthy Mediterranean diet and have a less stressful lifestyle. Is it not likely that these factors all contribute to their longevity?

I think so.

I also think that , as long as one gets a minimum of seven hours of sleep daily, it doesn’t matter if it occurs all at once or in two or more installments. When the mind and body need rest, the person craves sleep. As long as that need is satisfied, you are fine. I find that, with  most of my friends who are retired, an afternoon nap is an imperative, partly because they tire more easily and partly because they no longer get seven hours uninterrupted sleep at night. One of my friends who is in his eighties wrote me to say that the day’s activities are now accomplished ” between naps”.

So… never mind about terms like monophasic or biphasic.  Just listen to your body and all will be well.