Circadian Light Research Center Survey Confirms Harmful Health Effects of Blue-Enriched LED Light

The Circadian Light Research Center has released the results of a consensus survey of 248 leading scientists, which confirms that human circadian clocks are highly sensitive to blue wavelengths, and exposure to insufficient daytime blue-rich light and excessive blue-rich light at night, leads to many major health disorders.

Lead author Martin Moore-Ede, M.D., Ph.D., director of the Circadian Light Research Center and a former professor at Harvard Medical School, said, "Fewer than 0.5% of lights sold today protect circadian health by altering their blue content across day and night. Many people in the lighting industry claim that the circadian science is not sufficiently mature to incorporate into lights. So, we asked the leading scientists who work on circadian rhythms and light whether they agreed."

All scientists on PubMed who had published four or more peer-reviewed scientific papers since 2008 on circadian + light were invited to participate. Two hundred forty-eight of these scientists, who had published a total of 2,697 peer-reviewed publications on light and circadian clocks since 2008, completed an online survey with 40 potential consensus statements. They were asked to assess for each statement whether there was "no evidence,” "limited" evidence,” "good evidence," or "well established.” Consensus was established for 24 of these statements, where more than 2/3 agreed there was "good evidence" or it was "well established.”

Professor Sean Cain of Monash University in Australia, an author of the study, said: 'Exposure to blue-enriched LED light in the evening and night hours raises significant health issues because the human circadian system is highly sensitive to blue light near the 480 nm peak sensitivity of the melanopic intrinsically-photosensitive retinal ganglion cells (ipRGCs) in the human retina. Even small amounts of blue content in white LED light during nocturnal hours can cause circadian disruption and increase the risk of health disorders.'