An hour of exposure to blue light at night raises blood sugar levels and increases sugar consumption in male rats, according to a study from researchers at the Universities of Strasbourg and Amsterdam.
A press release on the study notes that retinal cells in the eye convey information directly to areas of the brain that regulate appetite—and that the same cells are sensitive to blue light.
Researchers exposed rats to one hour of nighttime blue light, and then gave them the option to choose among a nutritionally balanced food, water, lard, and sugar water. After exposure to blue light, male rats drank more sugar than they did during nights with no blue light exposure. The researchers found that the mice had an altered glucose tolerance, a pre-cursor for diabetes.
Anayanci Masís-Vargas, lead study author, said in the release: “Limiting the amount of time that we spend in front of screens at night is, for now, the best measure to protect ourselves from the harmful effects of blue light. In case it is necessary to be exposed to devices at night, I would recommend the use of apps and night mode features on the devices, which turn the screens more orange and less blue or the use of blue light filtering googles that are already available in the market.”