Blue Light Skin Protection

What Is Blue Light?

Blue light (BL), also known as high energy visible light (HEV), is emitted by electronic devices including smartphones, tablets, computers, and televisions. It is also a naturally occurring form of visible light emitted by the sun and has a wavelength range of 380 nm-500 nm. Of the forms of visible light, it has the highest energy and shortest wavelength, close to that of ultraviolet (UV) light. UV light further subdivides into UVC (200-290 nm), UVB (290-315 nm), and UVA (315-400 nm). Exposure to both UVA and UVB radiation is known to negatively impact the skin by directly and indirectly causing DNA damage within keratinocytes and melanocytes. The distinction between visible light and UV light is arbitrary in regard to the potential risks associated.

It is important to consider that BL emitted from the electronic devices that have become an integral part of our lives can have the potential to cause damage to our skin. It shares similar properties with damaging UVA light, and blue light can penetrate deeper in the dermis and may be linked to photoaging and carcinogenic effects with long-term exposure.

Impact of Blue Light on the Skin

Several studies have found that BL exposure causes damage to human keratinocytes. Because of the presence of BL, normal human keratinocytes (NHEK) sense that its daytime and will not undergo reparative cellular functions that normally take place at night. This is due to BL’s impact on PER1 levels, which are responsible for maintaining the nighttime rhythm within keratinocytes.¹

In addition to reducing the ability to repair cellular damage, BL also actively induces damage. BL irradiation can cause premature photoaging via intracellular oxidative stress and the overproduction of metalloproteinases (MMPs).^2,3 MMPs are endopeptidases secreted by keratinocytes and dermal fibroblasts in response to a variety of stimuli, including UV radiation. These proteins will then degrade collagen, elastin, and other components of the extracellular matrix (ECM) leading to premature aging.³ Furthermore, BL can activate tyrosinase protein complexes responsible for causing sustained hyperpigmentation in dark-skinned individuals.⁴ Continued exposure to visible light likely plays a role in the refractory nature of melasma, a skin condition characterized by brown or blue-gray patches or freckle-like spots, despite patient use of traditional UV-blocking sunscreens.⁵

Mineral (Physical) Sunscreens That Protect Against Blue Light

Mineral oxides, including iron oxide, zinc oxide, and titanium dioxide have the ability to absorb, scatter, and reflect radiation in both the visible and UV spectrums. This broad-spectrum coverage makes these minerals ideal ingredients for protection against blue light. While zinc oxide theoretically should provide protection against visible light, no clinical trials have been performed using only this ingredient. In fact, one clinical trial performed comparing all mineral sunscreens showed inferiority of zinc oxide at protecting against blue-light induced hyperpigmentation when not combined with iron oxide.⁶

Iron oxide

Boukari et al. (2015) conducted a randomized control trial comparing two sunscreen formulas.⁵ Formula A contained traditional UV blocking agents, while Formula B contained additional iron oxides and was tinted. Forty patients with melasma were randomized to receive either formula A or B and trained to apply the correct dose daily. Patients were instructed to apply one dose of the product twice daily and an additional dose 2.5 hours prior to sunlight exposure. The Melasma Area and Severity Index (MASI)⁷ score was used to evaluate the patients before sunscreen use and after 6 months. The results of this trial showed that patients who received the sunscreen formula without iron oxide had a larger median increase in their MASI score, indicating a worse outcome using this product. They further confirmed that the lower MASI was due to the presence of iron oxide and not the tinted nature of the sunscreen, since eight participants who had used un-tinted Formula A had also used makeup during the trial and did not see a reduction in MASI score. Similarly, in 2014, Castanedo-Cazares et al. studied 61 patients and found that the addition of iron oxide and zinc oxide to their sunscreen formulation provided better protection visible-light induced hyperpigmentation in melasma patients.⁸

Yellow iron oxide (YIO) was studied by Ruvolo et al. in 2018 in both in vivo and in vitro studies.⁹ A 4.5% YIO silicone-based formula was applied to the skin of 10 healthy volunteers with Fitzpatrick skin phototypes IV to VI and then tested via an in vitro model to predict the effectiveness of the YIO formula to absorb visible light. This was followed by an in vivo study using the same visible light source, but this time measuring the visible skin pigmentation darkening of the participants. The investigators found that YIO provided a 2.5 protection factor in vitro and 3.0 in vivo. These findings support the claim that the addition of YIO into sunscreen products protect against skin pigmentation that can occur with daily exposure to blue light.

Dumbuya et al. (2020) tested different formulations of mineral sunscreens to determine the most effective ingredient at protecting against visible light-induced pigmentation.⁶ Formula A contained zinc oxide and titanium dioxide (ZnO + TiO₂), formula B contained iron oxide and titanium dioxide (FeO + TiO₂), and formula C contained only iron oxide (FeO). Ten healthy women with Fitzpatrick skin phototype IV were included in the study. Each subject’s back was divided into 5 investigational 2x2 cm zones, with one negative control (no irradiation or product), positive control (only irradiated), and three pre-treated irradiated zones (the three products applied according to a randomization plan). Fifteen minutes of irradiation was performed on day 0, 1, 2, and 3 and clinical assessment of skin pigmentation was performed on day 0-4 and 14. The investigators found that formulations B and C (containing iron oxide) performed significantly better than the non-iron oxide containing formula at protecting against visible light-induced pigmentation. Interestingly, the formula containing FeO and TiO₂ did not perform better than the formula only containing FeO.

To find iron oxides in sunscreens, it is best to look for tinted sunscreens and under the inactive ingredients list.

Microfine Titanium Dioxide

Titanium Dioxide is the active ingredient found in some mineral, or physical, sunscreens. Microfine titanium dioxide contains reduced particle size of titanium dioxide (approximately 0.05 micrometers), which increases radiation scattering. Diffey and Farr (1991) compared the use of three sunscreen products (standard UVA/UVB chemical sunscreen SPF 15, microfine titanium dioxide SPF 15, and microfine titanium dioxide SPF 20) and their ability to protect against blue light induced erythema in photosensitive patients with chronic actinic dermatitis (CAD) and erythropoietic protoporphyria (EPP).¹⁰ They found that microfine titanium dioxide products provided protection against blue light, whereas the standard chemical blocker provided no protection. This is likely due to the reduced particle size, which increases the scattering per unit volume, particularly in the UV and BL end of the optical spectrum.

Herbs and Botanicals That Protect Against Blue Light

Hydroxytyrosol

Hydroxytyrosol is an herb extracted from olive fruits well known for its antioxidant properties which has been shown to be ten times more antioxidizing than green tea and two times more than coenzyme Q10. Avola et al. (2019) tested hydroxytyrosol’s ability to protect the skin from the deleterious effects of blue light with the use of cell cultures of keratinocytes and fibroblasts.³ Cultures were treated with hydroxytyrosol at different concentrations and irradiated with blue light. The study results showed that hydroxytyrosol protects skin keratinocytes and fibroblasts from damage induced by BL by preventing reactive oxygen species (ROS) formation, decreasing MMP levels, preserving collagen type I production, and reducing DNA damage.

Green Tea Extract

Green tea extract contains polyphenol flavonoid catechins, which protect against radiation-induced damage by acting as antioxidant and free radical scavenger due to their affinity to lipid bilayers. Epigallocatyechin-3-gallate (EGCG) is the major catechin in green tea leaves. In a study performed by Pires et al. in 2019, EGCG was found to protect cells from blue light irradiation via intermolecular interactions between EGCG and Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol) (sodium salt) (DPPG).¹¹ EGCG acts as a shield against UV light, slowing down the cascade of oxidizing events, protecting the hydration sites of DPPG lipids from degradation, and preventing lipid membrane permeability and cell death secondary to blue light.

Vitachelox

Vitachelox is a mixture of three standardized natural extracts rich in polyphenols: Vitis vinifera (grape) seeds, Camellia sinensis (green tea) leaves, and Quercus robur (oak) wood/bark. Grape seed extract has antioxidant, anti-inflammatory, and antimicrobial properties, and has been shown to protect against UV-induced oxidative damage and induction of MMPs.¹² As discussed above, green tea extract contains catechin epigallocatechin-3-gallate (EGCG), a flavonoid with antioxidant activity, that can protect lipid membranes against damage due to ROS. Finally, oak bark has antioxidant and antimicrobial properties.

Togni et al. (2019) tested the ability of Vitachelox to protect human keratinocytes cultured in vitro from damage due to blue light irradiation.¹³ Cells were incubated in solutions containing one of two concentrations of Vitachelox (0.01% or 0.005% w/v) and then exposed to blue light for either 6 or 24 hours. The researchers found that Vitachelox protects human keratinocytes by reducing protein damage (decreased protein carbonylation) induced by blue light radiation. Treated cells also experienced less oxidative-specific fluorescence, reinforcing the protective nature Vitachelox can have against blue light induced oxidation.

Key Points

1. Blue light is visible light emitted by electronic devices and is closest in wavelength and energy level to UVA light.
2. Blue light can have similar negative impacts to UVA light with prolonged exposure, including premature aging and hyperpigmentation.
3. Microfine titanium oxide and iron oxide, but not zinc oxide and standard-sized titanium oxide, may prevent the deleterious effects of blue light by physically blocking blue light radiation.
4. Antioxidants such as hydroxytyrosol, green tea extract, and vitachelox may protect against blue light-induced DNA and protein damage.