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Sleeping In Rooms With Even a Little Light Can Increase Risk of Depression, Study Finds (iflscience.com)

Posted by BeauHD on from the artificially-named dept.

Japanese researchers have found that even the slightest slither of light when trying to sleep could be linked to a heightened risk of depression, according to a new study published in The American Journal of Epidemiology. IFLScience reports: The reason behind this link is unclear, but the researchers believe it might be to do with the human circadian rhythm, the 24-hour cycle that tells us when to sleep and wake up, among other things, that is "programmed" by environmental factors. In the case of humans and many other creatures, light influences how much of the sleep-inducing hormone melatonin is pumped into our bodies, meaning we feel awake when the Sun rises and get sleepy when the Sun sets. This system works like a charm when there's only sunlight, moonlight, and a campfire to think about. However, the modern world is beaming with almost constant exposure to artificial light. Light at night (LAN) in a bedroom -- even a flash of a digital clock or streetlight creeping in from a crack in the curtains -- could screw with our natural sleep/wake cycle. The team behind the recent study assessed the sleep of almost 900 elderly people with no signs of depression. They found that people who slept in a room with 5 lux of light or more at night showed a "significantly higher depression risk" than those who slept in a completely dark room. For perspective, a household room with its lights on is around 80 lux and 10 lux is a single candle from 0.3 meters (1 foot) away.

4 of 177 comments (clear)

  1. Full Moon is ~0.1 Lux by pavon · · Score: 5, Interesting

    For comparison in the other direction.

    1. Re:Full Moon is ~0.1 Lux by PopeRatzo · · Score: 4, Interesting

      That means dim status LEDs are probably okay

      They're not OK. Really, it's worth the effort to try to cover them up as much as possible. Cultivate the best sleep you can and darkness is really good for sleep.

      --
      You are welcome on my lawn.
    2. Re:Full Moon is ~0.1 Lux by ImprovOmega · · Score: 3, Interesting

      For comparison in the other direction.

      We need a unit that Slashdot readers can understand. How much lux does a burning Library of Congress put out from one furlong?

      Well, if we extrapolate from a burning candle flame taking up one square inch visible and outputting 12.5 lumens at the source, then take one of the library of congress buildings, say the Thomas Jefferson building which is roughly 500ft on a side and around 60ft tall... Then we assume that the 500*60 = 30,000 sq ft side is completely engulfed, which would be 4,320,000 square inches * 12.5 lumens/sq in. = 54,000,000 lumens at the source. Multiply by three buildings and we get a total output of 162,000,000 lumens,

      Now convert to lux via assumption that you are one furlong (660 ft) away, lux = 10.76391 * lumens / (4 * pi * r^2) = ~318 lux.

      TLDR: So a burning LoC puts out roughly 318 lux at one furlong.

  2. Light Leaks Through Forehead! by SlashGodet · · Score: 1, Interesting

    When sleeping in a room with light pollution, I must cover my eyes (dark silk velvet works best) AND my forehead. Several friends polled do not notice any light leaking through their forehead. Do I have a hole in my head? Opinions regarding this phenomenon welcome. -arwen