A new study suggests that sleeping with a light on may increase the risk of multiple diet-related conditions, such as obesity, diabetes, and high blood pressure.
Researchers at the Northwestern Feinberg School of Medicine in Chicago, Illinois, discovered that the increasing number of light sources in daily life can affect not only our sleep but also our health.
Previous research from the same institution has established a link between nighttime light exposure and a person’s metabolism, as well as an increased risk of chronic disease.
Before going to bed, experts recommend turning off all lights, especially blue-colored lights, which are significantly more stimulating to the brain.
This study also suggests that elderly Americans are more susceptible to the negative effects of light exposure than their younger counterparts.
Dr. Minjee Kim, a neurology professor at Northwestern and the study’s author, said in a statement, “Older adults are already at a greater risk for diabetes and cardiovascular disease, so we wanted to determine if there was a difference in the frequency of these diseases about nighttime light exposure.”
For the study, 552 individuals between the ages of 63 and 84 were surveyed by researchers, whose findings were published in SLEEP.
Each participant monitored the amount of light they were exposed to overnight using a wrist device.
The participants were divided into two distinct groups. The first group slept in complete darkness for at least five hours per night, while the others were exposed to light at some point during their sleep period.
Participants were screened to determine whether or not they had obesity, diabetes, or hypertension.
They discovered that 73 percent of people who slept with some sort of light at night had high blood pressure, a 74 percent increase from the 60 percent of people who slept in complete darkness.
Diabetes risk doubled from 9.8 percent of those who slept in complete darkness to 17.8 percent of those who slept with a nightlight.
Obesity risk also increased by 82 percent, from 26.7 percent of those who slept without a light to 40.7 percent of those who slept with a light on.
‘Whether from a smartphone, leaving a television on overnight, or light pollution in a large city, we are surrounded by an abundance of artificial sources of light that are available 24 hours a day,’ said Kim.
Even though this particular study pertains to the elderly, there is evidence that more light at night and metabolic issues may increase the likelihood of developing the diseases.
Another Northwestern study from earlier this year established the correlation between nighttime illumination and metabolic dysfunction in all individuals. Additionally, it can impact a person’s ability to process glucose.
However, there is a chicken-and-egg factor at play, according to researchers. They cannot be certain that nighttime lighting is related to the prevalence of health conditions; it could be the other way around.
A person with diabetes, for instance, urinates more frequently and would want to leave a light on overnight.
Nonetheless, researchers assert that it is essential to minimize the amount of light present during sleep.
A person is advised to use blackout curtains or an eye mask to block out uncontrollable light from the outdoors.
If a person must have a light on, it should be as dim as possible and colored amber or orange, as blue or white can overstimulate the brain.
