A new study led by researchers in the United States has found that keeping the bedroom dark may significantly lower the odds of developing three major health problems. The findings were published June 22 in the journal ‘Sleep’. Older men and women who used night lights, or left their TV, smartphone or tablet on in the room were more likely to be obese, and have high blood pressure (HBP) and diabetes, compared with adults who were not exposed to any light during the night.
“Maybe even a small amount of light at night is not so benign, it can be harmful,” said lead author Dr. Minjee Kim, an assistant professor of neurology at Northwestern University Feinberg School of Medicine’s Centre for Circadian and Sleep Medicine in Chicago in the U.S. She cautioned, however, that the new study doesn’t prove that exposure to light during sleep causes any of these health conditions, only that there may be a link. And, Kim said, there may be a biological explanation beyond disrupted sleep that ties light to an increased risk for obesity, diabetes and HBP.
“It’s not natural to see those lights at night,” Kim said. “Light actually turns off some of the parts in the brain that tell our body it’s daytime versus nighttime. So, those sig-nals are messed up in a way, because the circadian signal is weakened, and over time, that has implications for our health.”