According to a new study published in the Proceedings of the National Academy of Science, people who curl up with their e-readers at night are putting both their sleep and health at risk. Scientists at the Pennsylvania State University in University Park, Pennsylvania have discovered that contrary to what some may think, using an e-reader to help one sleep in truth can cause a shift in your circadian clock and thereby significantly lower the quality of your sleep.
The research team reported that exposure to the light from e-readers during the evening and nighttime hours inhibits the release of the hormone melatonin which facilitates sleep. It also shifts one’s circadian clock making it more difficult to actually fall asleep when it’s bedtime.
Assistant professor of bio-behavioral health at Penn State, Anne-Marie Chang, stated that e-readers and similar electronic devices give off a light that is a short-wavelength-enriched light. It has a significantly higher amount of blue light — with a peak around 450 nm — than natural light. This light from e-readers is different from natural light in configuration and has a more powerful effect on circadian rhythms and sleep.
Chang and her teammates studied a dozen adults over a period of two weeks. They compared when the subjects read from iPads, serving as e-readers, before going to bed to when the same participants read from an actual print book prior to bedtime. The investigative group analyzed the subjects’ sleep, melatonin levels, alertness the following morning and other sleep-related factors.
Chang noted that perhaps the most unexpected result was that participants using e-readers were more fatigued and took more time “to become alert” the following morning. This resulted in actual consequences in terms of “daytime functioning”. She concluded the effects could “be worse in the real world as opposed to the controlled environment we used.”
E-Readers Harmful To Your Health