I was going to write a post about Daylight Saving Time yesterday, but I was feeling very draggy for some reason. It couldn’t have anything to do with that tiny little nudge forward of the clock’s hour hand Sunday morning, could it? One measly hour out of my life, taken from the middle of a weekend. How much damage could that possibly do?
Turns out, the damage potential is pretty impressive. “People often feel draggy the day after they have to set their clocks forward in the spring but often shrug off that feeling as trivial,” says Erik Herzog, PhD, a neuroscientist at Washington University in St. Louis who studies biological clocks. “In fact,” he says, “jamming our biological clocks into reverse, as daylight saving time does, has serious consequences.” (Aha! I knew it!)
“Daylight saving time does not seem to help conserve energy, one of its original goals. Instead, the evidence is that the one hour advance of our wall clocks each spring is associated with statistically higher rates of traffic accidents over the following three days and heart attacks over the following two days,” Herzog says.
You’ll want to check out Herzog’s research on his Washington University website, because Daylight Saving Time is only one of the ways we knock our circadian rhythms out of kilter.
In June of 2013 Herzog published research in the journal Neuron reporting the discovery of a crucial part of the biological clock: the wiring that sets its accuracy to within a few minutes out of the 1440 minutes per day. Two networks (VIP and GABA), they have found, ensure the clock runs as a coordinated, precise timepiece but one that can still adjust its timing to synchronize with the environment.
“We think the neurotransmitter network is there to introduce enough jitter into the system to allow the neurons to resynchronize when environmental cues change, as they do with the seasons,” Herzog said. However, he explains, “since this biological ‘reset button’ evolved long before mechanical clocks, artificial lights, and high-speed travel, it doesn’t introduce enough jitter to allow us to adjust quickly to the extreme time shifts of modern life, such as flying ‘backward’ (east) through several time zones.”
Understanding this system is important for understanding the health effects of messing with the body clock: in terms of daylight saving times, shift work, school starting times, medical intern schedules, truck driver hours, and many other areas where we attempt to push the body’s clock beyond its natural limits.
And as serious as heart attacks and traffic accidents are, researchers have also found that disruptions to the body clock caused by shift work contribute to obesity, and the World Health Organization lists shift work as a potential carcinogen.
It’s beginning to look as though feeling draggy is the least of my worries. It’s almost enough to make me consider moving to Arizona. But then . . . there must be research into the health effects of extreme heat, tarantulas and scorpions. I could look it up, but I think I’d rather take a nap.