Turn out the lights

[George K]

I've been fascinated by sleep for a long time, and @kluurs recommendation of Walker's book, "Why We Sleep," just reinforced my curiosity.

Now this...

Sleeping with even a little bit of light isn't good for your health

The small, 20-person study conducted by Zee and her team at Northwestern was designed to measure the physiological effects of 100 lux of artificial light on healthy adults while they were sleeping.

"This is about enough light that you could maybe see your way around, but it's not enough light to really read comfortably," says Zee. For the study, all the participants spent their first night sleeping in a mostly dark room. The next night, half of them slept in a more illuminated room (the light was placed overhead).

Meanwhile, the researchers ran tests on the sleepers: they recorded their brainwaves, measured their heart rates and drew their blood every few hours, among other things. In the morning, they'd give both groups a big dose of sugar to see how well their systems responded to the spike.

The results, published in the Proceedings of the National Academy of Sciences this month, show several clear differences between the two groups.

Unlike those who spent both nights in the dark, the group exposed to the light had elevated heart rates throughout the night. They also had increased insulin resistance in the morning, meaning they had more trouble getting their blood sugar into a normal range.

[Copper]

[Horace]

I use a sleep mask.