If our logs of traffic to this site are to be believed, many of you will read this post extremely late at night, much later than your parents would have thought of as bed-time. Yet more of you will read it in the wee hours, with precious little time left before you need to get up and go to work or school. And it's not just our visitors who behave this way. You'll often see our posts coming in after midnight, even on a school night, and even then we're rarely straight off to beddy-byes right after posting. It certainly seems that most people are burning the candle at both ends these days, partly because of work and family responsibilities, and partly because of the increasing availability and variety of communication and entertainment options, such as the Internet and cable television. I've always been one of those people who wholly embrace such new freedoms and, since I've never really needed a lot of sleep, have often found myself taking advantage of them late at night and early in the morning. I frequently read or deal with email and refereeing requests after midnight, and spend part of the early morning, around 6am, reading news sites and blogs before (when things are going ideally) exercising and heading off to work. This means that I can devote most of the day-time hours, plus large chunks of many evenings, to working, plus going out with my wife or with friends on occasion. I like living this way, although I must say that, now and then (every couple of months or so), it all catches up with me and I spend a Saturday essentially curled up in bed reading a novel while watching baseball. Many of my friends and colleagues have schedules of a similar tempo, although with different weightings of activities (often including getting up to get kids to school, which seems to be an immensely time-consuming process all on its own). We all seem pretty happy; but then again, we all also seem pretty exhausted from time to time. But maybe we shouldn't be so complacent. Sunday's Washington Post has an interesting article about recent scientific studies concerning the health implications of living with a long term sleep deficit. Although, as I'll mention briefly below, I don't think this is a stellar science article, it nevertheless made me sit up and think. Starting from the observation that most people need between seven and nine hours of sleep per night, the health complications that some researchers claim correlate with getting less than, say, six hours, comprise a scary list: heart disease, obesity, colon cancer, breast cancer, prostate cancer, diabetes and stroke. And I most definitely got the impression that they were just getting warmed up. This is a timely article because the results of several new studies, with rather large sample sizes, have recently been released. I found it a little difficult to ferret out serious details of these studies from the article, but one involves 10,000 subjects, and another is out of Harvard Medical School and involved 82,000 nurses. One thing I didn't like was that there was an attempt to provide balance with the usual glib "but others think differently" comment:
"There are Chicken Little people running around saying that the sky is falling because people are not sleeping enough," said Daniel F. Kripke of the University of California at San Diego. "But everyone knows that people are getting healthier. Life expectancy has been increasing, and people are healthier today than they were generations ago." Other researchers acknowledge that much more research is needed to prove that the apparent associations are real, and to fully understand how sleep disturbances may affect health. But ...
This seems like it is an interesting and potentially important comment from a credible researcher. However, the details behind Dr. Kripke's objections are not followed up, and one is left thinking either that his comment is unimportant or that something crucial is being ignored. This criticism aside, I did learn some interesting nuggets about the kind of research that's going on and what it might tell us about the potential hazards of our changing sleep habits. The connection with obesity leads to some particularly cute evolutionary speculation
The newest study on obesity, from Columbia University, is just the latest to find that adults who sleep the least appear to be the most likely to gain weight and to become obese. Other researchers have found that even mild sleep deprivation quickly disrupts normal levels of the recently discovered hormones ghrelin and leptin, which regulate appetite. That fits with the theory that humans may be genetically wired to be awake at night only when they need to be searching for food or fending off danger -- circumstances when they would need to eat to have enough energy. "The modern equivalence to that situation today may unfortunately be often just a few steps to the refrigerator next door," [Emmanuel] Mignot [of Stanford] wrote in his editorial [in the journal Sleep].
Despite all this, I can't imagine dramatically changing my lifestyle any time soon - I just like it too much. However, I think I will try to be a little more alert for those signs that I'm becoming over-tired, and maybe take that lazy Saturday or the occasional lie-in a bit more frequently than I do at present. It's for my health you understand. The fact that those sleepy mornings usually lead to deliciously decadent afternoons of baseball and contemporary literature is just a side effect of the medication.
