Reading this on an iPad at night? You may want to power down.
A study published in the Proceedings of the National Academy of the Sciences has found that people who use e-readers at night are drowsier in the morning that people who read from paper books. Researchers had twelve young adults (with an average age of twenty-five) who agreed to live in a private hospital for two weeks, so they could be very carefully monitored. For ten nights, they spent the four hours (from six to ten PM) before bed reading.
On five of those nights, they read from printed books. On the other five, they read from iPads. Blood samples were taken hourly to measure melatonin, which is a hormone that regulates sleep cycles.
Researchers found that, after the participants used the iPads, it took an average of ten minutes longer to fall asleep when compared to their print-book reading. On those nights, their levels of melatonin had been suppressed. Participants also rated themselves as less sleepy an hour before bed if they were using the iPads. However, the following morning, they felt sleepier than when mornings after reading from print books. It also took them a few more hours to fully ‘wake up’. There was no real difference in sleep duration, but participants who used iPads before bed experienced significantly less rapid eye movement (REM) sleep.
According to researchers, “Artificial light exposure has been shown experimentally to produce alerting effects [and] suppress melatonin . . .” which may be responsible for the “ . . . decline in average sleep duration and quality, with adverse consequences on general health.”
So: put down the e-reader, turn off the computer, power down Netflix, and do something that doesn’t involve a screen before bed.