Dont Read E-Books Before Bed!

Whether you’re a fan of electronic reading or not, it looks as though they’re here to stay. We could get into what’s great about them and what’s not-so-great about them, because there’s plenty to add to each category, but we’ve already done that. Plenty of times, in fact (see “Are eBooks Making Us Dumber?” or “How eBooks Transformed a Community in Rwanda”).

I read before bed. Unless I’m reading a terrifying thriller or closing my book after a massive cliff-hanger, reading knocks me out like an exhausted 2-year-old. People often find reading before bed the cure to not being able to fall asleep. However, one study suggests that the reading platform (paper vs electronic) strongly impacts falling, and staying, asleep.

The Proceedings of the National Academy of Sciences (PNAC) decided to investigate the effects of using “light-emitting eReaders” in the evening. Researchers from Brigham and Women’s Hospital in Boston studied a group of twelve healthy young adults. For five nights in a row, half of the participants read from e-readers about 4 hours before bed while the other half read print books. The groups then swapped reading material for 5 more nights in a row. What they found doesn’t shock me. From the PNAC report:

We found that the use of these devices before bedtime prolongs the time it takes to fall asleep, delays the circadian clock, suppresses levels of the sleep-promoting hormone melatonin, reduces the amount and delays the timing of REM sleep, and reduces alertness the following morning… 


Overall, we found that the use of portable light-emitting devices immediately before bedtime has biological effects that may perpetuate sleep deficiency and disrupt circadian rhythms, both of which can have adverse impacts on performance, health, and safety.

While many people agree that looking at a screen before bed messes up their sleep schedule, PNAC points out that it’s not just falling asleep that’s disturbed by using electronics before bed. People awoke feeling sleepier because they hadn’t entered REM, or spent less time in the deep-sleeping state. 

The study aimed to show “adverse consequences on general health” that disturbed sleep has on humans. Reading has become a common way for people to feel sleepy before going bed. As electronics become more commonplace, replacing paper books, newspapers and magazines, many turn to light-emitting electronics before bed. Nighttime e-readers “probably don’t realize that this techonology is actually making them less likely to feel sleepy,” Charles Czeisler pointed out to The Wall Street Journal.

There’s a bit of good news for those in favor of electronic reading. NPR points out that the original Kindle, which is an unlighted e-reader, shares “more characteristics with print books than their electronic cousins.”

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