New research shows that keeping your bedroom dark not only helps you sleep better, but also significantly reduces the risk of three major health problems.
Older men and women who use night lights or turn on their TVs, smartphones, or tablets in the room are more likely to be obese, have high blood pressure, and develop diabetes than adults who are not exposed to light at night.
“Perhaps even a small amount of night light is not so good, it can be harmful,” said the author. Minji Kim is a neurology assistant at the Center for Circadian and Sleep Medicine at the Feinberg School of Medicine at Northwestern University in Chicago.
He warned, however, that a new study could not prove that exposure to light during sleep causes any of these health conditions, and may be the only link.
According to Kim, there may be a biological explanation for the increased risk for obesity, diabetes and high blood pressure, in addition to sleep deprivation, which links light.
“It’s not natural to see those lights at night,” Kim said. “Light actually turns off certain parts of the brain, telling us that it’s between day and night in our body. So those signals are somehow distorted because the circadian signal weakens and over time it negatively affects our health.”
Thus, according to him, over time, light can lead to metabolism and heart disease.
Kim and her colleagues looked at more than 550 participants in the Chicago Healthy Aging Survey. For a week, 63 to 84-year-olds wore light meters in their bedrooms.
The study found that less than half of them slept in the dark for less than five hours. The rest were exposed to light during the darkest hours of the day, usually in the middle of the night.
Researchers say they do not know whether obesity, diabetes and high blood pressure can cause people to fall asleep with light on or whether light can lead to developmental conditions. However, they added that some people with leg cramps due to diabetes may use night lighting to prevent falls when they go to the bathroom at night.
Emerson Wickweir, a professor at the University of Maryland School of Medicine and head of the Department of Sleep Medicine, was not part of the study, but reviewed the results. According to him, the results show an increasing body of scientific evidence that the body’s circadian clock and sleep are important for overall health, especially for the elderly.
“These data show that exposure to night light increases the risk of two of the most common and costly chronic medical conditions in the U.S. and around the world – obesity and diabetes, as well as hypertension, a major risk factor for cardiovascular disease,” Wickwire said. . “Although this study requires careful observation in future studies, these are interesting findings.”
According to Weekwire, there are a number of factors that can contribute to the deterioration of the health effects of light at night.
“First of all, night lighting can be detrimental to health without regulating the circadian clock,” he said. “In addition to sleep, circadian health is critical to disease prevention and optimal functioning.”
Second, as Wickwire points out, light is a powerful melatonin suppressant.
“Melatonin, also known as the hormone of darkness, is associated with several health properties, including anti-inflammatory and antioxidant properties. Night light reduces melatonin,” Wickwire said.
In addition to increasing physiological stress, he said, night light can be a sign of general ill health, as people who wake up at night may engage in other dangerous behaviors.
To get all the benefits of sleep, Wickwire advises, “Create a sanctuary for sleep.” “The environment in your bedroom should be cool, dark, quiet and chaotic.”
Kim’s team also has tips for minimizing bedroom lighting:
Do not turn on the light. If you need to turn on a light for safety, keep it close to the floor.
The color of the light is important. Yellow or red / orange light stimulates the brain less. Do not use white or blue light and keep it away from the bed.
If you can’t control the outside light, use dark shadows or wear eye masks.
Make your bed so that the outside light does not touch your face.
The study was published June 22 in the journal Sleep.