In our daily routine, we get exposed to hours of artificial light from a variety of sources – computers, video games, office lights and, for some, 24-hour lighting in hospitals and businesses.
Everyone naturally have 24 hour body rhythm which is called circadian rhythm that keeps us in sleep wake cycle. When one goes to sleep, we get mental and physical rest which gets you ready for the new day.
New research done in animals shows that excessive exposure to light (light pollution) may impair this circadian rhythm. They exposed mice to continuous light exposure to 24 weeks and assessed their health parameters. What they found was that muscle strength, bone structure, and immune function are reduced by continuous light exposure.
During the study, the rats exposed to continuous light had less muscle strength and developed signs of early-stage osteoporosis. They also got fatter and had higher blood glucose levels. Several markers of immune system health also worsened, according to the report published in the medical journal Current Biology.
Interestingly when they were back in the regular routine of light exposure, those parameters did improve after two weeks
We cannot infer similar effect in humans but this does makes us think about effect of continuous light particularly in hospital intensive care units, elderly people in nursing homes and babies in neonatal units — places where artificial lights often are kept on for 24 hours a day.
We should also think about people exposed to hours of light emitted from video games and computers. There may be same effect from those light sources on health.