Doctors warn off e-readers before bed

Reading is bad for your health.

Actually, that's not quite true. Reading before bed time, and on your e-reader is bad for your health.

Well, maybe. At least that’s what a team from Harvard Medical School is saying.

They have been comparing reading paper books and light-emitting e-readers before sleep, and found that people have a harder time going to sleep if they were reading from an e-reader.

Because of that they had poorer quality of sleep, and were more tired the next morning.

So what the hell, technology?

Well, our bodies are designed to use light (mostly coming from the Sun) to find out what time of day it is, and to synchronise our body clock to it. But smartphones, tablets and LED lighting use blue light, a wavelength that is known to be able to disrupt the body clock.

It can slow the production of the sleep hormone melatonin, if consumed in the evening hours. Even e-readers like Kindle Fire or Nook produced similar wavelengths of light and would have the same impact on the reader.

The findings were published in the journal Proceedings of the National Academy of Sciences.

"Sleep deficiency has been shown to increase the risk of cardiovascular disease, metabolic diseases like obesity and diabetes, and cancer. Thus, the melatonin suppression that we saw in this study among participants when they were reading from the light-emitting e-reader concerns us”, lead researcher Prof Charles Czeisler told the BBC News.