How Can Light Color Be Used to Improve Health?

Color Considerations for Natural Light Therapy Solutions

Red Light
Throughout the last few decades, scientists repeatedly found that red light is the least likely to affect internal clocks. A 2013 Journal of Neuroscience report discussed the effects of red, blue and white lights on hamsters. At the conclusion of the respective study, researchers found that the rodents exposed to red light at night seemed less depressed than those exposed to the other colors of light. We have since found that this is because red light has a lesser effect on circadian rhythms, making it an excellent choice for evening lighting.

Similarly, a 2006 study published in Forschende Komplementärmedizin (Research in Complementary Medicine) found that different colors of light affect heart rate variability within minutes. In a 12-person study, those exposed to red and green lights, followed by a period of darkness, were the most likely to have higher levels of emotional arousal, which translate into better moods.

Blue and White Lights
In the study using hamsters, researchers found that the hamsters exposed to blue or white light experienced considerably more interruptions in their sleep patterns. This is because different light wavelengths affect how the brain reacts. Brain cells tend to be the most sensitive to blue wavelengths and the least sensitive to red ones.

In his article, Holzman stated that while many visible wavelengths have the power to reset circadian rhythms to a degree, blue light has the strongest impact—even in those who are blind. A study at the Harvard Medical School found that blue wavelengths suppressed melatonin levels at least twice as long as other light colors. Holzman highlighted other studies that discovered that blue light reduced sleepiness, elevated body temperatures, increase attentiveness and helped improve memory. Exposure to blue light in the early parts of the day can increase energy levels and reduce the after-lunch energy crash.

How Can Light Color Be Used to Improve Health?
The best color of light depends on your goals. If you want to increase productivity and promote a positive environment, short blue wavelengths are the best. Studies show that using blue light during the day helps prevent or reduce feelings of depression and anxiety, which is particularly beneficial to those who experience seasonal affective disorder.

To support good sleep hygiene, it’s best to limit your exposure to blue light before bed and throughout the night. Scientists found that those who have difficulties falling asleep might benefit from reducing the use of devices that emit blue light at night, such as computers, smartphones, television and tablets. It is also wise to use red night-lights to minimize the interruption to your circadian rhythm if you briefly get up in the middle of the night and require illumination.

By using the right light colors at the right time of day, you’ll boost your body’s ability to remain alert and active when it’s appropriate, and wind down at the end of the day. To learn how to incorporate light therapy in your home or office, browse Nature Bright’s comprehensive, eco-friendly solutions.