New evidence shows that exposure to the colors of light in a sunset may actually improve your sleep.
It’s been known by health experts for some time that exposure to light has an impact on normalizing the body’s internal clock. It’s because of this that humans get sleepy when it’s dark and wake up when it’s light outside. However, according to new research, it could be more than just light that affects our circadian rhythms; it may in fact be the color of that light that actually makes a difference.
For the purpose of the study, researchers from the University of California, Santa Cruz, examined how mice were influenced by the color of the light they were exposed to. They were particularly interested in discovering if the color of light affected the superchiasmatic nucleus — the part of the brain that helps vertebrates regulate time using electrical and chemical signals.
In order to test this, researchers exposed mice to different colors and intensities of light while measuring nerve signals in the superchiasmatic. Using an artificial sky, the mice were tested at various intensities of light, from bright light to complete darkness. And they were also tested when they were exposed to colors of light, such as the pinks and oranges that one might see during sunrise and sunset.
Researchers discovered that when the mice were exposed to light, as well as the various colors of light, they behaved normally. But in cases when they were exposed to light that went from bright to dark without the color cues, their superchiasmatic nerve signals lagged behind by about 30 minutes. Other physiological changes including a drop in body temperature, which might indicate the mice were ready to sleep, also lagged behind by 30 minutes without exposure to colors.
Other sleep studies that have examined changes within the superchiasmatic have found a strong association between reactions in mice and those in humans, which also confirms the findings of another recent study that discovered that when young people below 20 wore orange-tinted glasses at night while looking at the screens, they felt sleepier than those who wore nothing or their regular, clear-lensed glasses.
All of this leads to a conclusion that if humans are affected by the color, and not just the intensity of light, it can benefit health experts in coming up with better treatment options for those suffering from sleep disorders, even insignificant ones like jet lag.