The darker your bedroom, the better

Interesting research regarding the environment in which you sleep. Researchers are finding that the lightness of the room you sleep in may have an impact on your waistline.

I’m a big proponent of sleep. I always have been. Perhaps it’s party because I know what an awful job my body does of dealing with situations and responding to my commands when I haven’t slept well. During my graduate program I wrote a few research papers looking at things like Diabetes, Obesity and Shift-work. It was very easy to find studies looking at how going against our natural circadian clocks (that set our sleep/wake cycle) could create illness. The primary reason behind this was that those who were awake at night and had to sleep during the day were not having restful sleep during the day as their body was not coded to release melatonin (a sleep factor) at that time. Without the release of melatonin, the sleep cycle was easily disturbed resulting in poor rest patterns. And without appropriate amounts of rest, the body rebelled and accumulated extra weight resulting from the lack-of-sleep stress. The tendency to gain weight was independent of eating habits, meaning no matter how well you tried to eat a healthy diet, if you weren’t getting adequate sleep your body packed on extra weight and increased your risk of developing Diabetes.

Okay, so what does this recent research study have to do with that? Well, this study utilized a questionnaire to ask women about the environment in which they sleep. They were asked to rate the "lightness" of the room when they were sleeping. Light enough to read, light enough to see across the room (but not read), light enough to see your hand in front of you (but not across the room), or too dark to see your hand (or wears a mask) were the options to determine the lightness/darkness of the room. What they found was that independent of diet and exercise factors, those who slept in the lighter rooms were more likely to be overweight than those sleeping in darker rooms. The researchers theorized that this was because the presence of light, even when sleeping, can interfere with production of melatonin thus resulting in less restful sleep. This would be true even if the participant claims to be asleep the entire night - as melatonin would allow for more restful sleep waves with less time spent in the lightest levels of sleep.

So the best recommendations based upon this study are to sleep in a super dark room, without distractions (like the light from a television). If you live in a part of the country where this is difficult at times of the year (like us up here in the Pacific Northwest, or Alaska) you may want to look for blackout shades or purchase a sleep mask.

If you are waking up after sleeping 7-8+ hours and not feeling well rested, perhaps it’s time to evaluate your sleeping conditions as this should be enough to allow you to feel refreshed when you awake. 

If you do nothing else for your body to encourage good health, at least set yourself on the right foot with a good night’s sleep.

Am J Epidemiol. 2014;180(3):245-250. © 2014 Oxford University Press