Do you sleep, like 75% of the world's population, with artificial light in the bedroom? Well, know that this little habit has a real impact on the immune system, muscles and bones. This is a study carried out on mice by researchers at the Medical Center of the University of Leiden (in the Netherlands) and published in the journal Current Biology which revealed it.
To reach these conclusions, the researchers subjected mice to constant light for 24 weeks. This loss of day/night cues disrupts the brain's biological clock, which has physical consequences:the mice had muscle weakness and lower than normal bone density. Negative effects have also been observed on the immune system, but the researchers want to do more research before drawing any conclusions.
The good news (because yes, there is one!) is that the harmful effects of artificial light at night are perfectly reversible. The only requirement? Sleep in complete darkness, to restore the light/dark cycle. In the experiment conducted on mice, their state of health returned to normal after 2 weeks with a normal day/night rhythm.
This study comes in addition to previous ones which highlighted the negative effects of artificial light at night on sleep disorders, fertility or overweight, in particular on frail or elderly people. In short, from tonight, we turn off the laptop and sleep in the dark!