Un new study demonstrates that just one hour of exposure to blue light at night increases blood sugar levels and consequently its consumption.
When I speak of blue light I mean the type of light produced by the displays of all types, including mobile phones.
The study, carried out by Anayanci Masis-Vargas and colleagues from the universities of Strasbourg and Amsterdam, was presented this week at the company's annual conference on the study of ingestive behavior (SSIB) in Utrecht, the Netherlands.
Previous research has shown a strong connection between obesity and levels of artificial light at night. Much of the light that hits our eyes is connected to LED sources and displays, which emit high levels of blue light. The photoreceptors of the eye are very sensitive to this frequency and directly send the stimuli received to the brain areas that regulate appetite.
In his studies, Masís-Vargas and colleagues exposed guinea pigs to blue light. They did this by measuring food consumption and glucose tolerance throughout the following day. The accuracy of the experiment was almost obsessive: the rats used in the study are diurnal, staying awake during the day and sleeping during the night. The authors observed that after just one hour of exposure to blue light at night, glucose levels were completely altered.
What exactly happens?
The researchers tried to understand better what happens to appetite and food choices after exposure to blue light. The guinea pigs were therefore given the choice between standard balanced foods, water, lard and sugar water. After the first phase, the researchers observed a huge increase in the consumption of sugar water by the guinea pigs exposed to blue light compared to those not exposed.
In other words, the study clearly shows how much damage nighttime exposure to LED screens causes. At least to those that don't filter blue lights. If confirmed in humans, this reactive mechanism should be directly linked to weight gain and the development of diabetes.
“Limiting the time spent in front of screens at night is the best way. We must protect ourselves from the harmful effects of blue lights: for those who find themselves forced to expose themselves, I recommend the use of apps that filter the light. There are different ones available."
