March 11, 2013

Two Sleeps a Night May Be Better than One

The axiom -- seven solid hours of sleep to maintain good health -- is now being questioned by medical researchers and historians.

Until a century and a half ago, people typically slept in two distinct phases bridged by an hour or more of wakefulness. This break was often a period of quiet early morning wakefulness. With the afternoon nap (siesta), this sleeping pattern was normal before the Industrial Age.

I've stumbled into this very sleep cycle, which I feel has greatly enhanced the quality of my life. Two recent media reports make me think what I'm doing isn't so odd. Unfortunately, many others like me assume something is wrong, and they rush to the doctor for unneeded sleeping pills.

The Case Against a "Solid Seven Hours" as a Sleep Goal
I reported last October, on a New York Times story "Rethinking Sleep" by David Randall. Reviewing the work of historian A. Robert Ekirch, Randall comments:
The modern assumption that consolidated sleep with no awakening is the normal and correct way for human adults to sleep may lead many people to approach their doctors with complaints of maintenance insomnia or other sleep disorders. If Ekirch's theory is correct, their concerns might best be addressed by assurance that their sleep conforms to historically natural sleep patterns.
In last week's issue of The New Yorker, Elisabeth Kolbert's article "The Science of Sleeplessness," also addresses the issue. She reports on studies from the book "The Slumbering Masses" by Matthew J. Wolf-Meyer, an assistant professor of anthropology at the University of California at Santa Cruz.

Nowadays, Wolf-Meyer says, adults are expected to go to bed around 11pm and stay there until about 7am. Anything else -- napping during the day, sleeping in bursts, waking up in the middle of the night -- is considered unsound and unhealthy.

This didn't use to be the case. Until a century and a half or so ago, Wolf-Meyer observes, "Americans, like other people around the world, used to sleep in an unconsolidated fashion, that is, in two or more periods throughout the  day."

They went to bed not long after the sun went down. Four or five hours later, they woke from their "first sleepe" and rattled around -- praying, chatting, smoking, or making love. Eventually they went back to bed for their "second sleepe."

Wolf-Meyer blames capitalism in general and American capitalism in particular for transforming once ordinary behavior into conduct worthy of medication. Today's focus on "seven solid hours of sleep," he says is "largely the product of the industrial workday, which began as a dawn-to-dusk twelve-to-sixteen stretch and shrank to eight hours only at the turn of the twentieth century."

Both of these articles suggest that for the many people who have trouble getting enough sleep between 11pm and 7am, the problem is the sleep pattern itself; people don't naturally follow that pattern.

Tomorrow, I'll report on my lifelong struggle with insomnia and my recent escape from the handcuffs of a "solid seven hours."

No comments: