Did you know that blue light use at night can increase your blood sugar levels and make you crave sweets? It's true.
A recent collaborative study between the University of Amsterdam and the the Society for the Study of Ingestive Behavior (SSIB) in Utrecht, Netherlands found that even just one hour of exposure to blue light, the light emitted from most of our electronic devices, is enough to raise blood sugar levels and increase sugar cravings. The study was performed on male rats, and not humans.
The researchers wanted to study this because previous studies have found a strong correlation between obesity levels and the amount of artificial light exposure at night. The majority of artificial light that we're exposed to comes from electronic devices and LED source. These previous studies determined that retinal cells in our eyes are sensitive to blue light and directly convey messages to the area of the brain that regulates appetite.
The study directly measured blue light exposure at night and how it relates to food consumption habits and glucose tolerance the following day. On the day following exposure to nighttime blue light, the rats were given a choice between sugar water and a nutritionally balanced food. The rats drank more sugar water on the days following nighttime blue light exposure.
The researchers found out that after only one hour of nighttime blue light exposure from digital devices, glucose tolerance was altered in the male rats. This is a warning sign for pre-diabetes. The researchers concluded that blue light exposure at night is disruptive to appetite control. It may increase our tendency to snack on higher glycemic foods, which could potentially lead to obesity and metabolic disease.
These researchers warn that we would be better off limiting our exposure to nighttime blue light from our electronic devices and other LED sources. If you must use a blue light emitting device at night, install an app such as f.lux that filters blue light by making it more orange. Or get yourself a pair of blue light blocking glasses. Companies like Prospek, True Dark, and Pixel make good ones. I even had my prescription glasses from my optometrist tinted with blue light filters recently. Most eye doctor's offices can now do this. It's worth it if you stare at screens for an extended period of time like I do.