We lose, we snooze

A bold prediction: On Monday, you will be feeling sleepy, very sleepy.

You will have trouble getting out of bed. If you are a teenager, you will have even more trouble than usual. If you are an early-morning commuter, you may struggle to keep your eyes open as you drive along darkened streets.

What will trigger this mass bout of drowsy driving, this predictably mopey Monday? It will be the first weekday after the start of daylight-saving time – that once-a-year “spring ahead” that robs us of one hour of sleep (returned when clocks “fall back” in November).

It’s just one hour, but experts in chronobiology – the study of our internal body clocks – say it takes most people several days to adjust (the fall change also is disruptive, but less so). One recent study from German researchers, published in the journal Current Biology, found that some habitual night owls have trouble getting adequate sleep for weeks after the spring shift – which, in effect, demands we all go to bed and get up an hour earlier.

At best, “we’ll have a lot of groggy people on the highways the first couple of days,” says Michael Smolensky, a chronobiologist at the University of Texas, Houston. Smolensky is among researchers who have documented increases in traffic accidents in the days after the shift (offset, other studies show, by fewer accidents during months of better-lit evening rush hours).

That temporary accident bump “is scary,” Smolensky says. But he and other experts say it’s just one example of the trouble we humans cause ourselves when we tinker with our body clocks. And that’s something we do with increasing regularity. In some cases, the consequences may be serious and long-lasting. Consider:

“Some of us spend our nighttime hours bathed in artificial light, despite studies suggesting health risks. The latest study, published in Chronobiology International, found Israeli women living in neighborhoods well-lit at night had more breast cancer than women in darker neighborhoods. Meanwhile, shift work – working at night or on rotating shifts – has been called a “probable carcinogen” by the World Health Organization. Years of overnight light exposure and sleep deprivation are chief suspects in that link.

“Teens in many communities are starting school around 7 a.m., despite a growing awareness that teen brains work better on later schedules. A 2006 poll from the National Sleep Foundation found 28 percent of teens fall asleep in school and 15 percent drive drowsy at least once a week.

“We’re spending less time outdoors, depriving ourselves of sunshine, nature’s master time-keeper. That could make it harder for our bodies to maintain healthy rhythms, Smolensky says.

“We’re getting less sleep overall, thanks in part to the 24/7 lure of our electronic devices. “People are staying up all night doing online trading, following the markets in Hong Kong,” says Fred Turek, a researcher at Northwestern University.

Of course, no one suggests humans return to unlit caves or adopt universal 10 p.m. bedtimes. “Nurses have to work at night. Planes have to fly at night,” says Erhard Haus, a University of Minnesota researcher who chaired the WHO panel on shift work. And while some school districts are starting their high schools later, others are balking, citing conflicts with after-school activities and efficient bus schedules.

The chronobiologists are thinking about all this and mulling solutions. Some are high tech (lower-impact lighting for night workers); some are no-tech (brief afternoon naps for sleepy teens).

Meanwhile, those extra-foggy days next week may do us some good – if they remind us that when we mess with Mother Nature, she messes with us, too.