When I was recently asked by a colleague if it is true that blue light has a deleterious effect, I was not sure how to best answer. I was skeptical at first about the “blue light phenomenon,” so I went online to get a better idea of the concept. I found a mixture of non-authoritative sites that either doubted or swore by the blue light effect. Although it looked like there were a lot more non-authoritative sites that said that blue light has an effect, I wanted something more authoritative—some evidence. So, I jumped on PubMed (https://pubmed.ncbi.nlm.nih.gov/), where peer reviewed scientific/authoritative references are listed. When I searched for “blue light,” I got 31,729 results (as of November 2020). Here is an example of some of the paper titles:

• The Dangers of Blue Light: True Story!
• Low-Energy Light Bulbs, Computers, Tablets and The Blue Light Hazard
• Evaluating The Blue-light Hazard From Solid State Lighting
• Blue Light From Light-emitting Diodes Elicits a Dose-dependent Suppression of Melatonin in Humans
• Change of Blue Light Hazard and Circadian Effect of LED Backlight Displayer With Color Temperature and Age
• A search on “blue light” and “skin” gave me 1,345 results. Here are some headlines:
• Blue Light Disrupts the Circadian Rhythm and Create Damage in Skin Cells
• Blue Light-induced Oxidative Stress in Live Skin
• Effects of Blue Light on Inflammation and Skin Barrier Recovery Following Acute Perturbation. Pilot Study Results in Healthy Human Subjects
• Hydroxytyrosol From Olive Fruits Prevents Blue-light-induced Damage in Human Keratinocytes and Fibroblasts

As it appears from these titles, there is plenty of “scientific” evidence that blue light has a deleterious effect. An article from Cosmetics & Toiletries entitled, “Testing Tactics in Skin: A View of Visible Light Protection,”¹ discussed the biological effects of blue light in skin and the dangers of blue light—with appropriate references.

In addition to the above listed titles from scientific peer review articles, consider the following samples from peer reviewed scientific papers. In no particular order or importance, just what I found in my personal files. Recently, Happi² and C&T³ featured work published in the J. Cosmetic Derm.⁴ that discussed Amorepacific’s development of a scientific instrument that emits blue light at a wavelength of 456nm causing skin pigmentation. Skin pigmentation! Should we call that a “Blueburn?” How about “BLB” (“Blue Light Burn”)? Anyway, you cannot get any more direct evidence that blue light has an effect on skin, because it is visual—regardless if it is beneficial or deleterious. Complement this with the scientific paper from PLoS ONE entitled, “Visible Light Induces Melanogenesis in Human Skin Through a Photoadaptive Response”⁵ which showed the effect of “visible light on the pro-pigmentation pathways and melanin formation in skin. Exposure to visible light in ex-vivo and clinical studies demonstrated an induction of pigmentation in skin by visible light. Study results showed that a single exposure to visible light induced very little pigmentation whereas multiple exposures with visible light resulted in darker and sustained pigmentation.” These findings, the authors maintained, “have potential implications on the management of photo-aggravated pigmentary disorders.” Another paper, “Irradiation of Skin with Visible Light Induces Reactive Oxygen Species and Matrix-Degrading Enzymes,”⁶ examined the physiological response of skin to visible light (400-700nm; 1 nm = 10^-9 m = 10^-7 cm).

According to my college physics book,¹² the visible spectrum’s color wavelengths, in nanometers, are approximately:

• Violet, 400-450;
• Blue, 450-500;
• Green, 500-550;
• Yellow, 550-600;
• Orange, 600-650; and
• Red, 650-700.

The smaller the wavelength the higher the light energy¹⁴ and the higher the probability that it will interact with matter to transfer that energy and affect matter. Irradiation of human skin with visible light induced production of ROS (reactive oxygen species), pro-inflammatory cytokines, and matrix metalloproteinase (MMP)-1 expression. All indicative of deleterious effects suggesting, that outside of UV, which ranges from 100-400 nm,¹³ visible light may also contribute to signs of premature skin photo-aging. A paper from the J. Bio. Chem. entitled, “Blue Light Induces Mitochondrial DNA Damage and Free Radical Production in Epithelial Cells”⁷ showed that blue light is toxic to non-pigmented epithelial cells. The authors showed a loss of mitochondrial respiratory activity compared with cells maintained in the dark; i.e., absence of light exposure. This loss became greater with increasing exposure time. In short, light exposure significantly damaged mitochondrial DNA. “Isolated mitochondria exposed to light generated singlet oxygen, superoxide anion, and the hydroxyl radical;” i.e., ROS. They conclude that “visible light can cause cell dysfunction through the action of reactive oxygen species on DNA and that this may contribute to cellular aging, age-related pathologies, and tumorigenesis.”

A scientific paper from Oxidative Med. Cell. Longevity entitled, “Blue Violet Light Irradiation Dose Dependently Decreases Carotenoids in Human Skin Which Indicates the Generation of Free Radicals,”⁸ exposed nine healthy volunteers to blue light. The authors showed through a non-invasive manner that the cutaneous carotenoid concentration dropped down in a manner similar to that caused by UV, leading to the conclusion that “blue light at high doses could represent a comparably adverse factor for human skin. The degradation of cutaneous carotenoids indirectly shows the amount of generated free radicals and especially reactive oxygen species in human skin.” The J. Photochem. Photobio.; B: Biology, reported in an article entitled, “Effects of Blue Light Irradiation on Human Dermal Fibroblasts,”⁹ that “blue light at different wavelengths may induce varying degrees of intracellular oxidative stress with different physiological outcome that could contribute to premature skin photo-aging.” They found that irradiation with blue light led to intracellular oxidative stress and toxic effects in a dose and wavelength dependent manner.

A scientific paper from Free Radical Bio. Med., entitled, “Blue Light-induced Oxidative Stress in Live Skin,”¹⁰ used mice and cultured human keratinocytes exposed to blue light. Investigators detected ROS, meaning  blue light could produce oxidative stress in live skin by preferentially affecting mitochondria. They concluded that exposing human skin to blue light contained in sunlight contributes to skin aging similar to UVA. The final example I am providing from a plethora (thousands) of scientific papers (from PubMed), is from the J. Derm. Sci., entitled, “Carbonylated Proteins Exposed to UVA and to Blue Light Generate Reactive Oxygen Species Through a Type I Photosensitizing Reaction.”¹¹ Investigators showed that blue light is absorbed by the skin to excite carbonylated proteins (CPs) resulting in the generation of superoxide anion radicals. CPs are generated by the reaction of basic amino acid residues in proteins with aldehyde compounds produced during lipid peroxidation.¹¹

According to the authors, “CPs in the stratum corneum (SC) impact skin conditions such as skin moisture functions including water content and trans-epidermal water loss (TEWL). CPs can be seen in the SC from sun-exposed sites compared with sun-protected sites.” CPs are the biggest culprit in aging. “The results suggest that the superoxide anion radicals produce CPs in the SC through lipid peroxidation in the sebum, and finally affects skin conditions including color and moisture functions.”

As the reader can see, there is plenty of “scientific” evidence that blue light—due to physical, chemical and biological principles—has a deleterious effect on the skin and by extension, as well as any living tissue exposed to it—at least under the experimental condition described in this handful of papers.

In short, from what is described here, blue light is absorbed by certain chemical entities in biological matter resulting in reactive oxygen species that are known to have a primary role in aging through multiple mechanism.

So yes! It is hard to ignore the “blue light phenomenon.” Blue light comes from multiple sources, including the sun. Its deleterious effect on the skin depends on exposure. However minor that effect may be, it behooves the cosmetic industry to protect its consumers and capitalize on it by creating products that protect. Will the day come that we would be talking of some kind of “BLB Protection Factor” (“BPF”)?

For additional information regarding this topic, actives and products that protect, the reader is encouraged to read reference 15. I’m convinced blue light’s prolonged accumulated effect also contributes to skin aging along with other electromagnetic radiation. 

Note: The viewpoints expressed in this article are those of the author and do not necessarily reflect those of any competent authority or his company. The purpose of this article is to guide and inform the reader. The author does not endorse or represent anyone. The reader is encouraged to verify any opinions and facts the author presents.

References

1. Holtz, R. (February 9, 2018). Testing Tactics in Skin: A View of Visible Light Protection. Cosmetics & Toiletries: https://www.cosmeticsandtoiletries.com/testing/equipmentevaluation/Testing-Tactics-in-Skin-A-View-of-Visible-Light-Protection-473595923.html.
2. Happi Staff. (September 3, 2020). Amorepacific’s Evaluation of Blue Light Protection. Happi: https://www.happi.com/contents/view_breaking-news/2020-09-03/amorepacifics-evaluation-of-blue-light-protection/.
3. Behrens, M. (September 10, 2020). Researchers Develop Device to Evaluate Blue Light Harm. Cosmetics & Toiletries: https://www.cosmeticsandtoiletries.com/testing/equipmentevaluation/Researchers-Develop-Device-to-Evaluate-Blue-Light-Harm-572349761.html.
4. Li Jo, H., et al. (2020). Clinical Evaluation Method for Blue Light (456 nm) Protection of Skin. J. Cosmetic Derm., 19(9): 438–2443.
5. Randhawa, M, et al. (2015). Visible Light Induces Melanogenesis in Human Skin through a Photoadaptive Response. PLoS ONE, 10(6): 1-14; https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0130949.
6. Liebel, F., et al. (2012). Irradiation of Skin with Visible Light Induces Reactive Oxygen Species and Matrix-Degrading Enzymes. J. Invest. Derm., 132: 1901–1907.
7. Godley, B.F., et al. (2005). Blue Light Induces Mitochondrial DNA Damage and Free Radical Production in Epithelial Cells. J. Bio. Chem., 280(22): 21061–21066.
8. Vandersee, S., et al. (2015). Blue Violet Light Irradiation Dose Dependently Decreases Carotenoids in Human Skin Which Indicates the Generation of Free Radicals. Oxidative Med. Cell. Longevity, 2015: 1-7.
9. Opländer, C., et al. (2011). Effects of blue light irradiation on human dermal fibroblasts. J. Photochem. Photobio.; B: Biology, 103: 118–125.
10. Nakashima, Y., et al. (2017), Blue Light-induced Oxidative Stress in Live Skin. Free Radical Bio. Med., 108: 300-310.
11. Mizutani, T., et al. (2016). Carbonylated Proteins Exposed to UVA and to Blue Light Generate Reactive Oxygen Species Through a Type I Photosensitizing Reaction. J. Derm. Sci., 84: 314-321.
12. Sears, F.W., et al. (1977). University Physics, 5th Edition. Addison-Wesley Publishing Company, Inc. U.S.A.
13. https://en.wikipedia.org/wiki/Ultraviolet, retrieved November 2020.
14. National Aeronautics and Space Administration (NASA). The Electromagnetic Spectrum. https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum2.html, retrieved December 2020.
15. Geria, N.M. (November 2020). Blue Light Defenses & Protective Skin Care. HAPPI, 57(11): 34 – 36.

---

About the Author  

Lambros Kromidas, MS, PhD, is Vice President & Regulatory Team Leader, Shiseido.  Prior, he worked at Avon, Coty, Beiersdorf, and RIFM. He received his PhD in toxicology from St. John’s University, New York, NY, and conducted post-doctorate research at Cornell University Medical College, Department of Physiology, New York, NY.