Your Shiny New E-reader May Be Harming Your Sleep
Digital electronic reading devices, such as the Kindle Fire, the iPad, or other illuminated, e-reader, or e-book devices, are a wonderful invention. Rather than lugging around a heavy book, or dragging your home library with you on the road, you can now transport an entire world of words with you where ever you go.
I think reading is one of life’s great pleasures. Taking a good book to bed is a wonderful way to unwind at night and explore new worlds before drifting off to restful sleep. Some books, especially hardcovers, can be weighty enough to put a little strain on your wrists, though. So it’s only natural that many Americans have embraced feather-light e-readers that can be enjoyed on public transportation as easily as the beach or in bed.
There’s just one problem. These devices emit light. Newer models even emphasize their improved brightness. When riding on a darkened subway car, illuminate text is hugely helpful. But when you’re in bed, just before sleep, this light presents an under-appreciated problem: it may be interfering with your sleep and having an significant—negative—impact on your health.
According to an important new study by researchers at Brigham and Women’s Hospital, e-readers are an emerging threat to American’s health. “We found the body’s natural circadian rhythms were interrupted by the short-wavelength enriched light, otherwise known as blue light, from these electronic devices,” said Anne-Marie Chang, PhD, associate neuroscientist in BWH’s Division of Sleep and Circadian Disorders. “Participants reading [a light-emitting]—eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock and reduced next-morning alertness than when reading a printed book.”
And make no mistake, this is not just about being a little sleepy. Deep, restful, restorative sleep is crucial for the maintenance of overall health. Research suggests, for example, that the body performs important immune system maintenance during sleep, including correcting mistakes that could lead to the development of cancer.
This news suggests to me that it may be time to go back to good old paper books for your nighttime reading. There’s no need to toss your shiny new e-reader. Just save it for the beach, or that next family trip to grandmother’s house. And, by the way, this also applies to any and all electronic devices that emit light. Experts warn that they should be banished from the bedroom. Turn off the computer. Put away the smart phone, and leave the television in the den. Sleep in a cool, totally dark room, free of any artificial light sources for the best, most healthful sleep. And keep in mind, better sleep is not only linked to better health, it’s also been linked to better weight control.
Anne-Marie Chang, Daniel Aeschbach, Jeanne F. Duffy, and Charles A. Czeisler. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. PNAS, December 22, 2014 DOI: 10.1073/pnas.1418490112