Now more than ever we are exposed to more artificial light than we are natural light which isnt really great for your bodys natural sleep/wake cycle, researchers say. In fact, Cancer Epidemiologist Richard Stevens and his team members at UConn Health at the University of Connecticut believe that such overexposure has possible ties to cancer, obesity, diabetes and other health issues. Along with co-author Yong Zhu from Yale University, they explain the known short-term and suspected long-term impacts of circadian disruption in an article published in the British journal Philosophical Transactions of the Royal Society B.
Stevens believes that overexposure to artificial light is an emerging health topic. It's become clear that typical lighting is affecting our physiology," he said. "But lighting can be improved. We're learning that better lighting can reduce these physiological effects. By that we mean dimmer and longer wavelengths in the evening, and avoiding the bright blue of e-readers, tablets and smart phones."
Stevens says those devices emit enough blue light when used in the evening to suppress the sleep-inducing hormone melatonin and disrupt the body's circadian rhythm, the biological mechanism that enables restful sleep. As smartphones and tablets become more commonplace, Stevens recommends a general awareness of how the type of light emitted from these devices affects our biology. He says a recent study comparing people who used e-readers to those who read old-fashioned books in the evening showed a clear difference -- the e-readers showed delayed melatonin onset.
It's a new analysis and synthesis of what we know up to now on the effect of lighting on our health," Stevens continued. "We don't know for certain, but there's growing evidence that the long-term implications of this have ties to breast cancer, obesity, diabetes, and depression, and possibly other cancers. It's about how much light you're getting in the evening. It doesn't mean you have to turn all the lights off at eight every night, it just means if you have a choice between an e-reader and a book, the book is less disruptive to your body clock. At night, the better, more circadian-friendly light is dimmer and, believe it or not, redder, like an incandescent bulb.