Iron Oxides Protect Skin Against High Energy Visible Light

Iron Oxides protect against HEV light, emitted by smartphones
Woman using smart phone

Consumer electronics, including smartphones and computers, emit high energy visible (HEV) light. With numerous studies now indicating that HEV light contributes to various elements of photoaging, including increased wrinkles, worsening skin laxity and hyperpigmentation, researchers Eric F. Bernstein, MD, Harry W. Sarkas, PhD, and Patricia Boland, BA, sought to determine whether iron oxides, used in several skin care formulations, may help protect against HEV exposure.

The results of their in vitro study, published in the Journal of Cosmetic Dermatology (November 18, 2020), showed that sun protection formulations that contain iron oxides provide added protection against HEV light.

The authors noted that HEV light in the violet/blue spectrum has a wavelength range between approximately 400nm and 500nm, adjacent to UVA. Sunscreens containing titanium dioxide and zinc oxide protect against UVA and UVB radiation but provide limited protection against HEV light. Antioxidants are protective against injury from free radicals as a result of UV and blue light exposure, but cannot prevent blue light-induced melanogenesis. Therefore, additional ingredients that protect against HEV light may be beneficial, particularly for patients struggling with melasma and other pigmentation concerns.

The study compared three SPF formulations from Colorescience containing titanium dioxide, zinc oxide, red iron oxide, yellow iron oxide and black iron oxide with control (no sunscreen). The percent of HEV light attenuation was measured in vitro using diffuse transmittance spectroscopy using a Perkin Elmer Lambda 750 UV/Vis/NIR Spectrophotometer equipped with a 100mm integrating Labsphere and PbS detector.

Products formulated with zinc oxide, titanium dioxide and red, yellow and black iron oxides demonstrated 71.9% to 85.6% attenuation across the tested wavelengths of 415nm to 465nm compared to 3.9% to 4.9% with no sunscreen.

“My entire career has been laser-focused on the use of lasers in medicine and the study of sunlight. One thing I’ve learned all too well is that sunlight causes a range of problems for our skin including fine lines and wrinkles, enlarged pores, redness, pigmentation, skin sagging and skin cancer," said Dr Bernstein. "Visible blue light is the most energetic, and therefore the most damaging light, to reach our skin and penetrates more deeply than ultraviolet rays. I have been interested, for many years, in ways to protect skin against all wavelengths of light. This research is important because it shows that skin care products formulated with iron oxides, combined with mineral sunscreen actives and other ingredients, effectively shield skin against harmful, high-energy, visible wavelengths.”

Read the full study here

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