WEDNESDAY, June 22, 2022 (HealthDay News) — Keeping your bedroom dark not only helps you get a good night’s sleep, but can also significantly reduce your risk of developing three major health conditions, according to a new study.
Older men and women who used nightlights or left their TVs, smartphones or tablets on in the room were more likely to be obese and to have high blood pressure and diabetes, compared to adults who did not. were exposed to no light at night.
“Maybe even a small amount of light at night isn’t so benign, it can be harmful,” said lead author Dr. Minjee Kim, assistant professor of neurology at the Center for Circadian and Sleep Medicine. from Northwestern University Feinberg School of Medicine in Chicago.
She cautioned, however, that the new study does not prove that exposure to light during sleep causes any of these health problems, only that there may be a link.
And, Kim said, there may be a biological explanation beyond disrupted sleep that links light to an increased risk of obesity, diabetes and high blood pressure.
“It’s not natural to see these lights at night,” Kim said. “The light actually turns off some of the parts of the brain that tell our bodies it’s day or night. So those signals are disrupted in some way because the circadian signal is weakened and over time that has implications for our health.”
So, she said, over time, the light can cause metabolic and heart disease.
Kim and her colleagues looked at more than 550 participants in the Chicago Healthy Aging Study. The 63 to 84-year-olds wore devices that measured the amount of light in their rooms for a week.
Less than half spent five hours in complete darkness while they slept, according to the study. The others were exposed to light even during the darkest five hours of the day – usually in the middle of their sleep at night.
The researchers said they don’t know if obesity, diabetes and high blood pressure cause people to sleep with a light on or if the light leads to the conditions developing. But, they added, some people with numbness in their feet due to diabetes may want to use a night light to help prevent falls when they have to use the bathroom at night.