You should always be careful about whom you sleep with, even if that someone is on television or is a light bulb.
A study just published in JAMA Internal Medicine suggests that sleeping with something that produces light may not be a bright idea. The study showed an association between the amount of artificial light, such as light produced by a television or a night light, in a room while sleeping and gain in body weight over time. Is this yet another reason why you shouldn’t install a constant strobe light above your bed?
This study was basically an analysis of data from 43,722 women, who had been enrolled in the Sister Study from July 2003 through March 2009 and followed an average of 5.7 years after being enrolled. A team from the National Institute of Environmental Health Sciences of the National Institutes of Health (Yong-Moon Mark Park, MD, PhD, Alexandra J. White, PhD, Chandra L. Jackson, PhD, MS, Clarice R. Weinberg, PhD, and Dale P. Sandler, PhD) conducted the analyses. Study participants ranged from 35 to 74 years old in age.
On enrollment, each participant had her height and weight measured and answered questions about her sleeping habits. When asked about the lights that are regularly on while they sleep, the participants had options of providing answers such as “light from a small nightlight or clock radio,” “light from other rooms,” “light from outside shining in through windows at night, such as car headlights, street lights, or porch lights,” “light from a television on in the room for most or all of the night,” “1 or more lights on in the room,” and “daylight.” The research team excluded anyone who answered with “daylight” because such folks may have been unusual, such as night shift workers, Alaska residents, or vampires.
Based on these responses, the researchers then placed each participant into one of four categories: no light, small nightlight in the room, light outside the room, and light or television on in the room. Those who slept with a mask on (not a Batgirl one, but one that actually covered their eyes) fell into the “no light” category.
While enrolled in the study, each participant then completed every two to three years questionnaires that asked about changes in her health-related behaviors and health status, including her weight.
The results of the analyses shed some light on the association between artificial light while sleeping and changes in weight and body mass index (BMI). Compared to the study participants who did not have any artificial light exposure while sleeping, those who did have such exposure were 17% more likely to have gained 5 kilograms or more, 13% more likely to have had at least a 10% increase in BMI, 22% more likely to have developed overweight status, and 33% more likely to have developed obesity.
The concern is that artificial light may be disrupting your sleep in ways that you may not even notice. Your sleep may not be as deep or as sustained. This in turn could affect your metabolism or your hunger. Could being in a more awake state for longer periods of the day signal to your body, “you’ve got to eat more so that you have more energy to do whatever it is that you are doing that’s keeping you awake longer”? Less restful sleep could also be increasing stress hormones in your body that in turn could alter your metabolism and lead to weight gain. Poorer quality sleep could also affect your mental health as well, which as a result could affect your eating.
Of course, the results of this study are associations and not proof of cause-and-effect. For example, what if other things such as stress or lack of social support are leading people to have both trouble sleeping without the comfort of a light being on and weight gain? More studies are necessary to more clearly establish the mechanisms behind what is happening. Nonetheless, this study is further evidence that obesity is a complex systems issue. It is the result of the biological, behavioral, social, or other systems being disrupted. The study also is further evidence of how the quality of your sleep may affect your mental and physical health in many different ways.
So don’t ignore the importance of good sleep hygiene. Sleep hygiene is not cleaning yourself before you go to sleep. Rather, the National Sleep Foundation defines sleep hygiene as “a variety of different practices and habits that are necessary to have good nighttime sleep quality and full daytime alertness.” One of these practices is to make sure that your bedroom is actually dark enough while you sleep. It can help to maintain a cave-like environment in your bedroom. Here are some ways to do that:
- Buy curtains or blinds that actually block light. That sheer chiffon curtain may look dreamy but how functional is it? A curtain is supposed to block light not make you look like you are in a dream sequence or the Fortress of Solitude.
- Make sure that your curtains or blinds are the right size. Consider curtains or blinds to be like thongs. They need to fit your windows well. If they are too small or too large, the result could be seeing something that could be quite disturbing.
- Make sure your blinds are really closed. Leaving your blinds open can be like wearing pants with the fly open. You wouldn’t be blocking what’s supposed to be blocked.
- Consider black-out curtains or blinds. These are special curtains or blinds that are designed and reinforced to block light.
- Turn out lights outside your bedroom. If you leave the hallway light on, the light may leak into your room.
- Cover the cracks in your door. If you’ve ever watched the movie Poltergeist, you’ll know that a surprising amount of light can leak from under the door.
- Unplug all unnecessary electronics. This includes turning off any surge protectors, charging devices, and electronic disco balls that may be in your bedroom.
- Use a timer for your TV. If you must go to sleep with a late night TV host, then consider setting a timer so that the TV automatically shuts off once you are asleep. This way you don’t wake end up waking up with someone else, like a morning TV show host.
Here is a situation where you want to be in dark about everything. The increase in devices that offer you artificial light at all times of the day may be messing with your bodies in all kinds of ways. That’s why when you are about to go to sleep, it helps to unplug. Really unplug.