The Secrets of Sleep (D.T. Max, National Geographic, May 2010):
“From birth, we spend a third of our lives asleep. After decades of research, we’re still not sure why.”
The article looks first at the very rare illness of fatal familial insomnia (FFI), known to exist in only 40 families worldwide. It usually manifests in one’s 50s, gradually eroding the ability to sleep over the course of a year, and it ends in death. Researchers know that FFI is caused by proteins attacking and destroying the thalmus, but “they don’t know why this happens, or how to stop it, or ease its brutal symptom.”
That’s because we don’t really know why we sleep in the first place, though all mammals and birds do, even at the risk of becoming prey for predators.
“What can possibly be the payback for such risk? ‘If sleep doesn’t serve an absolutely vital function,’ the renowned sleep researcher Allan Rechtschaffen once said, ‘it is the greatest mistake evolution ever made.’
There are theories as to why we need sleep, of course (e.g., the brain needs it for memory consolidation; it’s needed to boost the immune system and control infection; “because we get sleepy”), and those are examined in the rest of the article, as well as insomnia, which in America is a problem for about 1/5 of the population, with sleeping pill prescriptions up 54% in 2008 over the previous four years.
About insomnia, Max says:
“If a medical problem in some less private, less mysterious bodily function were causing such widespread harm, governments would declare war on it.”
Harvard sleep researcher Charles Czeisler says that :
“going without sleep for 24 hours or getting only 5 hours of sleep a night for a week is the equivalent of a blood alcohol level of 0.1 percent. Yet modern business ethic celebrates such feats. ‘We would never say, “This person is a great worker! He’s drunk all the time!’“
Interesting to me because I just read about how Martha Stewart sleeps only 4 hours per night routinely and is, demonstrably, full of energy. See Aug. 2010 NYT article about how not sleeping is the habit of highly successful people.)