Sleeplessness and Nighttime 'Light Pollution'

Researchers suggest that streetlights, neon signs interfere with good rest

By Karen Pallarito

HealthDay Reporter

TUESDAY, March 1, 2016 (HealthDay News) -- People who live in neighborhoods that are lit up at night with neon signs and streetlights are more likely to report sleep problems, new research suggests.

Although the study doesn't prove cause-and-effect, the scientists believe that intense outdoor illumination in the evening interferes with quality of sleep.

People with high nighttime light exposure, for example, were more likely than those in low-lit regions of the country to be dissatisfied with their sleep quantity or quality, by a margin of 13 percentage points, the findings showed.

"It was interesting for us to see how much this light in our streets was having an impact on us," said study author Dr. Maurice Ohayon, director of the Stanford Sleep Epidemiology Research Center, in California.

The findings are to be presented in April at the American Academy of Neurology's annual meeting in Vancouver, Canada. Research presented at meetings is typically considered preliminary until it is published in a peer-reviewed journal.

George Brainard, a professor of neurology and neuroscience at Thomas Jefferson University in Philadelphia, called the Stanford team's analysis an "important epidemiological study."

"Exposure to light at night can have powerful biological and behavioral consequences," said Brainard, who also serves as director of Jefferson's Light Research Program.

However, the associations noted in the study may be due to other factors, he cautioned.

"In an urban area, we all tend to short our sleep a lot more because it's a busy, vibrant environment, so we're up later at night, and maybe we're exposed to bright light inside of our apartment or house," he said.

"Do I think that light is part of the culprit? Absolutely, I do," Brainard said. "Do I think this study has proven that it's street lighting? No, I think the jury's out on that."

People's sleep patterns are regulated by two systems, according to the National Sleep Foundation. The body's natural circadian rhythm, or sleep/wake cycle, causes you to feel more alert or sleepy, depending on the time of day. And, after being awake for 16 or more hours a day, your drive to rest, called sleep/wake homeostasis, kicks in.