Outside in Appalachia: Getting Outside at Night

Jul 20, 2018

One recent evening at Blackwater State Park, naturalist Paulita Cousins was leading about two dozen visitors on a night hike by the lake.


“When it’s dark we’re naturally supposed to be ...?” she asked.

“Sleeping,” the group responded in unison.  

“And light,” she warned, “is actually messing up a chemical in our body to make us be healthy individuals.”

It may sound drastic, but exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms, and there's some early evidence that lower melatonin levels might explain the association with cancer.

More than a third of American adults don’t get enough sleep, according to the Centers for Disease Control and Prevention, and the problem is even worse in West Virginia.

Despite being one of the darkest spots on the east coast, West Virginia ties with New York with almost 40 percent of residents reporting less than seven hours of sleep a night. Not getting enough sleep is associated with metabolic problems, issues with insulin resistance, and weight gain, according to the National Institutes of Health.

Interestingly, nationwide, sleep patterns look quite similar to maps of obesity and diabetes prevalence.

 

So if your circadian rhythms are messed up, how do you reset them?

“We did a study, actually a series of three studies, where we used camping as a tool to escape the light exposure you get in modern cities,” said Chris Depner, a postdoctoral fellow in the sleep lab of the University of Colorado Boulder. He was part of a study to see, if we escaped all electrical light, what would that do to our bodies and our biological clocks?

“Over a week, our biological clocks basically tuned themselves to the timing of sunrise and sunset,” he said. “So that means during the normal, biological or environmental night, our bodies were trying to sleep. And during the day, that’s when we were supposed to be awake.”

They then tested the hypothesis over just a weekend of camping.

“And we saw that about 70 percent of that effect happened over just the weekend,” he said. “So that means when – you think about that – on Monday morning when you wake up, your body is going to be more in tune with the environmental cycle versus perhaps if you’re living in the electrical lighting environment.”

While light of any kind can suppress the secretion of melatonin, blue light at night – such as the kind found on phones, computers and TVs – does so more powerfully. A Harvard study found that when people are exposed to blue versus green light, blue light suppresses melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much.

What isn’t clear from the research is whether spending more time outside does the trick, or if simply dimming lights in your home and turning off the TV, cell phone and other electronic devices a couple hours before bed would suffice.