by The Cosmetic Chemist Staff
July 15, 2016
Over the last several years there has been growing concern about the effect of blue light on the skin. This has mostly been fueled by increasing amounts of exposure to this type of light by artificial light sources (e.g., compact fluorescent lamps) and electronic devices which use light emitting diodes (LEDs), such as television screens, computer monitors, tablets, and smart phones.
For many years, most home lighting systems were based on incandescent light in which a metal filament is energized resulting in a glowing effect or illumination of the metal. However, in the last decade there have been radical changes in indoor lighting as well as the widespread use of electronic devices that emit blue light. Most technologists agree that our exposure to blue light will continue to increase over time in tandem with the increasing use of these lighting sources and devices.
Most of us are already aware of the damaging effects of ultraviolet (UV) radiation on the skin. This consists of light emitted by the sun in the 280-400 nm range of the electromagnetic spectrum, which is further classified as UVB (280-320 nm) and UVA (320-400 nm). Fortunately, highly energetic and damaging UVC (200-280 nm) rays are filtered by ozone (O3) in the stratosphere and do not reach the Earth’s surface. Overall, exposure to UV radiation leads to a number of deleterious effects in skin including photoaging, photoimmunosuppression, and photocarcinogenesis.
Blue light (400-500 nm) represents a portion of the visible electromagnetic spectrum (400-700 nm) that is adjacent to the UVA region in terms of emitted wavelength or energy of the light waves. It actually corresponds to the spectral distribution of both violet (400-450 nm) and blue (450-495 nm) light. Although many artificial light sources appear white, they give off an intense emission in the blue light region, which is stronger than that present in natural sunlight.
There has been growing concern due to the damaging effects of blue light on eye physiology, which leads to degradation of retinal photoreceptors and could be implicated in macular degeneration.1,2 Ironically, blue light has been used to treat sleep disorders, in which it functions to reset circadian rythyms.3 It is also benefecial for the treatment of infants with neonatal jaundice, where bilirubin accumulates in the blood and tissues (eyes, skin, etc.) resulting in an overall yellow appearance. Since blue light can penetrate fairly deep into the skin, it is used as a form of photodynamic therapy to dissolve bilubrin so that it can be excreted from the body.4
Acne vulgaris is a common disease, which is reported to affect approximately 80% of the population.5 The bacteria, Propionibacterium acnes, is implicated in the development of acne, and is the primary target of most medical treatments, which usually consist of antibiotics or immunotherapy. Blue light therapy has been found to be efficacious in the treatment of certain infectious diseases, especially in the case of acne.6-8 While the exact mechanism of how blue light functions to combat acne has not been elucidated, it is well known that blue light has broad spectrum antimicrobial activity against gram-positive and gram-negative bacteria. In contrast to UV light therapy, it does not require the use of exogenous photosensitizers and, overall, is considered less damaging to mammalian cells.9
Notwithstanding the beneficial effects of blue light on the skin, there is considerable concern in the skin research community in regard to its deleterious effects. A recent study published by researchers in the Department of Dermatology at Charité-Universitätsmedizin Berlin highlights the depletion of carotenoids in skin by blue light, which is believed to be facilitated by the generation of reactive oxygen species.10 Mechanistically, it has been shown that exposure to visible light leads to the excitation of cellular photosensitizers, ultimately leading to reactive oxygen species production, specifically hydroxyl radical, superoxide anion, and singlet oxygen.11 In pigmented cells, melanin and lipofuscin have been identified as photosensitizers; however, in non-pigmented cells the photosensitizers remain unknown, although it appears that flavin-containing oxidases, the cytochrome system, heme-containing proteins, and tryptophan-rich proteins are likely candidates.11
While not specifically focused on blue light, a number of studies have shown that visible light can promote melanogenesis and erythema in skin and lead to the production of reactive oxygen species.12-14 On the other hand, a clinical study at the Radboud University Nijmegen Medical Centre in Nijmegen, The Netherlands demonstrated that short-term blue light use in skin therapy does not cause DNA damage or premature photoaging.15 Regardless, there is still a great deal of interest in this subject, which has even lead to the launch of a commercial product (Moonlight Primer by MAKE Beauty) designed to protect the skin from blue light emitted from smart phones, tablets and laptops.16
Fundamental research and clinical studies that are well designed and statistically sound should help shed light on unanswered questions concerning the cost-benefit balance of blue light exposure to the human population. Until then we may wonder if ‘protection’ from blue light is a fad, or an essential need to fortify our skin’s defenses.
References
1. G. Tosini, I. Ferguson, and K. Tsubota, Effects of blue light on the circadian system and eye physiology, Mol. Vis., 22, 61-72 (2016).
2. I. Jaadane, P. Boulenguez, S. Chahory, S. Carré, M. Savoldelli, L. Jonet, F. Behar-Cohen, C. Martinsons, and A. Torriglia, Retinal damage induced by commercial light emitting diodes (LEDs), Free Radic. Biol. Med., 84, 373-384 (2015).
3. D.C. Holzman, What´s in a color? The unique human health effects of blue light, Environ Health Perspect., 118, A22-A27 (2010).
4. J.F. Ennever, Blue light, green light, white light, more light: treatment of neonatal jaundice, Clin. Perinatol., 17, 467-481 (1990).
5. P.F. Liu, Y.D.Hsieh, Y.C. Lin, A. Two, C.W. Shu, and C.M. Huang, Propionibacterium acnes in the pathogenesis and immunotherapy of acne vulgaris, Curr. Drug Metab., 16, 245-254 (2015).
6. M.H. Gold, A. Andriessen, J. Biron, and H. Andriessen, Clinical efficacy of self-applied blue light therapy for mild-to-moderate facial acne, J. Clin. Aesthet. Dermatol., 2, 44-50 (2009).
7. A. Charakida, E.D. Seaton, M. Charakida, P. Mouser, A. Avgerinos, and A.C. Chu, Phototherapy in the treatment of acne vulgaris: what is its role? Am. J. Clin. Dermatol., 5, 211-216 (2004).
8. S. Ammad, M. Gonzales, C. Edwards, A.Y. Finlay, and C. Mills, An assessment of the efficacy of blue light phototherapy in the treatment of acne vulgaris, J. Cosmet. Dermatol., 7, 180-188 (2008).
9. T. Dai, A. Gupta, C.K. Murray, M.S. Vrahas, G.P. Tegos, and M.R. Hamblin, Blue light for infectious diseases: Propionibacterium acnes, Helicobacter pylori, and beyond? Drug Resist. Updat., 15, 223-236 (2012).
10. S. Vandersee, M. Beyer, J. Lademann, and M.E. Darvin, Blue-violet light irradiation dose dependently decreases carotenoids in human skin, which indicates the generation of free radicals, Oxid. Med. Cell Longev., doi: 10.1155/2015/579675, Epub (2015).
11. B.F. Godley, F.A. Shamsi, F. Liang, S.G. Jarrett , S. Davies, and M. Boulton, Blue light induces mitochrondrial DNA damage and free radical production in epithelial cells, J. Biol. Chem., 280, 21061-21066 (2005).
12. L.R. Sklar, F. Almutawa, H.W. Lim, and I. Hamzavi, Effects of ultraviolet radiation, visible light, and infrared radiation on erythema and pigmentation: a review, Photochem. Photobiol. Sci., 12, 54-64 (2013).
13. B.H. Mahmoud, C.L. Hexsel, I.H. Hamzavi, and H.W. Lim, Effects of visible light on the skin, Photochem. Photobiol., 84, 450-462 (2008).
14. M. Randhawa, I. Seo, F. Liebel, M.D. Southall, N. Kollias, and E. Ruvolo, Visible light induces melanogenesis in human skin through a photoadaptive response, PLoS One, 10(6), e0130949 (2015).
15. M.M. Kleinpenning, T. Smits, M.H. Frunt, P.E. van Erp, P.C. van de Kerkhof, and R.M. Gerritsen, Clinical and histological effects of blue light on normal skin, Photodermatol. Photoimmunol. Photomed., 26, 16-21 (2010).
16. http://makebeauty.com/products/moonlight-primer-1.