The blue light from our smart devices happens to be a real trend in the skincare market nowadays. But, is that the blue light that should concern ourselves the most? Maybe not. Get to learn the differential impact of the distinct types of light on your skin and the only formulations that can get you covered from the blue light that matters most.
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Hello guys! Yes, we spend tons of time in front of our computers, smartphones, TVs, and LED lights. Skincare brands want you to take care of that. However, not any botanical extract or antioxidants here and there can do the job.
It is not the skincare market trend nor the artificial blue lightning that led me to write this post. The thing is that it is already spring, and the sun is shining brighter! And I realized we have only talked about the impact of the exposure to the ultraviolet sunlight on the skin. So let’s get now into the blue!
Not just ultraviolet rays reach the skin
The sunlight spectrum comprises three types of light: ultraviolet (invisible to our eye), visible (the light that we can see), and infrared (which we sense in the form of heat). Have a look at the image below.
Ultraviolet C (UVC) rays are the most energetic. Luckily, they get absorbed by the ozone layer and do not reach us. UVB rays (290-320 nm) reach the epidermis (the outermost layer of the skin) and can cause sunburns and skin cancers.
UVA makes it to the dermis, fosters photo-aging (wrinkles, laxity, dark spots), and can also provoke skin cancers; it comprises the UVA2 (320-340 nm) and UVA1 (340-400 nm) regions. UV rays make up <10% of the sunlight radiation.
Visible light constitutes about 44% of the sunlight (at the sea level), can get even deeper into the dermis (due to its longer wavelength), and comprises the colors of the rainbow: from blue [or High Energy Visible Light (HEVL), close to 400 nm] to red, up to 700 nm.
And infrared light (700-1440 nm) can reach the fatty tissue below the dermis (aka, the hypodermis).
Are the cutaneous defense mechanisms against ultraviolet and blue lights similar?
Both ultraviolet rays (UVB/A) and visible rays induce two kinds of protective reactions in the skin:
1· A stress response
2· Pigmentation of the skin.
Yet, the magnitude, significance, and molecular mechanisms involved in each of them differ.
Ultraviolet radiation induces synchronized stress and pigmentation responses
Exposure to UV light damages the cellular DNA, generates free radicals (reactive oxygen species, or oxidative stress), and causes inflammation within the skin.
Within minutes several cellular survival programs are activated (this is collectively known as the stress response). These comprise DNA repair, cellular proliferation, and recruitment of the immune system.
Both DNA damage and the presence of inflammatory cytokines foster the production and secretion of Melanocyte Stimulating Hormone (MSH) – a pro-pigmenting hormone – by keratinocytes (the cells that make up the epidermis).
That stress response promotes skin pigmentation later on (within hours and up to days). MSH binds specific receptors in melanocytes (the pigment-producing cells).
That triggers the production of the central regulator of melanocytes, the molecule MITF, which induces the generation of pigment (melanin). Melanin is then transferred to the rest of the epidermis and physically protects the cellular DNA against UV-induced mutations.
MITF controls the synchronization of the stress and pigmentation responses. The levels of MITF increase during the stress response and need to decay for pigmentation to take place 1.
That’s why UVB exposure every other day induces more skin pigmentation than daily exposure 1. How is that possible? When there is a prolonged stress response due to daily UV exposure, MITF levels do not decrease as they should. That leads to suboptimal pigmentation (see the image below).
Therefore, direct daily sunlight exposure disrupts the dynamics of MITF. That fosters not only weaker pigmentation but also higher cell proliferation (thus, the epidermis becomes thicker). That is no joke since MITF plays a role in melanoma development, the most deadly skin cancer.
Non-daily UVB fosters a protection system that responds to the total amount of UV exposure.
On the contrary, daily direct sunlight exposure results in a protection system sensitive to the frequency of exposure and biased for a stress response (rather than pigmentation).
Thus, this dual UV-protection system appears to be more efficient when UV exposure doesn’t happen continuously. Therefore, the avoidance of significant daily sunlight exposure (or adequate physical protection and topical sunscreen usage instead) seems to be a great idea 🙂
Blue light induces stress-independent immediate and long-lasting pigmentation
Visible light – aka the sunlight spectrum from 400 to 700 nm (from blue to red) – can also promote free radicals formation in the skin, yet in a lower magnitude than UV rays 2. However, it appears that visible light doesn’t cause DNA damage 3. Thus, visible light seems to generate a weaker and less harmful stress response, not comparable in quantity nor quality to that triggered by UV rays.
Moreover, among the visible spectrum, only blue light can produce skin pigmentation 4. Blue light stimulates melanin production by acting directly on melanocytes. How? Through a light-sensitive receptor, Opsin-3 5, that we also have in our eyes.
The melanocytes in our skin sense blue light through Opsin-3. When this occurs, Opsin-3 gets activated, induces MITF, and triggers an immediate and persistent pigmentation.
The image above illustrates the main differences between UV and blue light-induced skin pigmentation: indirect, delayed, and short-term after ultraviolet light versus direct, immediate, and long-term upon blue light.
In all skin phototypes (see the image below) melanocytes have Opsin-3. However, both UV and blue light-induced melanin production are mainly relevant to darker skin types (phototypes III-VI) 5. Melanocytes of those darker phototypes make melanin more easily. That does not mean that skin phototypes I and II cannot make melanin at all after blue light (or UV) stimulation.
The double-edge of blue light: immediate protection at the expense of hyperpigmentation?
Blue light triggers an immediate, more potent, and longer-lasting skin pigmentation 6. Also, it does not require a previous DNA damage step and does not affect cell proliferation.
That would be a natural and innocuous mechanism for the induction of protection of the skin against sunlight if it were not for two facts:
· visible light can also induce free radicals production in the skin;
· visible light is involved in pigmentary disorders (such as melasma or dark spots).
Besides, it’s known that blue light and the longer UV wavelengths (UVA1) have a synergistic effect 7. That is, together they induce more potent hyperpigmentation. Guess why the blue light-protection skincare market is booming! 😉
Now that the molecular pathways which lead to blue light hyperpigmentation are better known, innovative treatments that specifically target those could arise. Likewise, there might be ways to gather just the benefits of blue light-induced pigmentation when appropriate. Cool, right?
Can blue light from smart devices and artificial lightning tan our skin?
Visible light pro-pigmenting properties are dose-dependent. That means that the blue rays from sunlight have a much higher pro-pigmenting and oxidative stress-inducing ability than artificial blue light sources. You can get significant blue light-induced pigmentation in just an hour or two of direct sunlight exposure.
Nonetheless, bear in mind that multiple factors may influence that. For instance, the number of LED lights you have simultaneously switched on or the time of the day at which you get exposed to natural blue light.
Therefore, adequate exposure to sunlight is the main factor of concern. But that may not be enough if, at the same time, you get massive exposure to artificial blue lightning and are not mindful of that. For example, you could reduce your exposure to devices/artificial blue lighting in the evening, which harms your sleep quality and overall health.
What skincare ingredients can protect you against the non-desired effects of blue light?
Large particle (> 200 nm, non-nano) zinc oxide and titanium dioxide, the active ingredients contained in mineral (physical) sunscreens, can offer some protection against High Energy Visible Light. However, those large particles leave a heavy white cast on the skin. That is why most mineral sunscreens contain micronized (10-200 nm) zinc oxide and titanium dioxide and thus do not protect against blue light.
Apart from those, currently, the only skincare ingredients that can protect you from HEVL are iron oxides. They can block HEVL rays, hence avoiding their penetration into the skin. Three main types of iron oxides infuse skincare products with HEVL protection:
· red (Fe2O3): CI 77491;
· yellow (Fe (OH)3/FeOOH): CI 77492;
· black (Fe3O4): CI 77499.
Tinted sunscreen products contain iron oxides. They protect against blue light when iron oxides are present in a concentration of at least 3%. Each of the three iron oxides provides a slightly different blue light attenuation profile. Therefore, sunscreens that include the three of them (rather than one or two) seem to offer superior blue light photoprotection 8.
Furthermore, the use of mineral sunscreens with iron oxides increases the efficacy of treatments for melasma (when compared with mineral sunscreens without iron oxides) 9.
Nonetheless, an oral antioxidant combined with a regular (non-tinted) sunscreen may not be superior to sunscreen alone for preventing the worsening of hyperpigmentation after sun exposure 10. The same applies to topical antioxidants. So don’t be fooled by sunscreen formulations that claim to protect you better against blue light just by the power of antioxidants or botanical extracts!
Blends of the three iron oxides confer foundation (and makeup in general) with skin-alike colors. However, those formulations may not protect effectively against blue light. And they provide a weak protection against ultraviolet rays (even if that is good, you won’t apply enough product to be optimally protected). Therefore don’t forget to apply a proper sunscreen product beforehand. 🙂
Some sunscreen products that protect well against HEVL
My intention now is to illustrate you with some examples of different products that you can find out there.
Tinted chemical and mineral sunscreens
Although you cannot guess the percentage of iron oxides by reading the label, here I leave you some potentially good options.
Altruist Anti-Redness & Pigmentation SPF50
INCI list: Aqua, C12-15 Alkyl Benzoate, Butyl Methoxydibenzoylmethane, Ethylhexyl Salicylate, Ethylhexyl Stearate, Octocrylene, Titanium Dioxide, Potassium Cetyl Phosphate, Glycerin, Aluminum Starch Octenylsuccinate, Titanium Dioxide (nano), Dicaprylyl Carbonate, Phenylbenzimidazole Sulfonic Acid, CI 77492, Butyrospermum Parkii Butter, Cetearyl Alcohol, Glyceryl Stearate, Acrylates/Ammonium Methacrylate Copolymer, Panthenol, Isopropyl Myristate, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Aminomethyl Propanol, Silica, Phenoxyethanol, CI 77499, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Triethyl Citrate, CI 77491, Bisabolol, Caprylyl Glycol, Piroctone Olamine, CI 47005, Diethylhexyl Sodium Sulfosuccinate, CI 42090, Silver Chloride, Propylene Glycol, Citric Acid.
That is a chemical sunscreen. It offers an excellent UVB defense and also greater UVA protection than many other broad-spectrum sunscreens.
As you can see on the ingredient list above, it has the three iron oxides at different concentrations. It’s only available in one shade (light brown). It might suit medium phototypes better (III-IV) since it has a slight copper undertone that you might not like if your skin is fair.
Bioderma Photoderm NUDE Touch SPF50+
That is a lightweight mineral sunscreen. It comprises the three iron oxides in distinct concentrations (open the link above to access the ingredients list). It leaves a matte finish. It is available in three different shades that suit phototypes II-IV.
Colorescience Sunforgettable Total Protection Face Shield SPF50
That is a mineral sunscreen range (popular in the US and the UK). It contains 12% micronized zinc oxide and all three iron oxides. It brings about a slightly shiny finish and comes in three different shades (Original, Glow, and Bronze).
Colorescience Sunforgettable Total Protection Brush-On Shield SPF50
That is a powder sunscreen available in four different shades (fair, medium, tan, and deep). It is handy for reapplications over your regular sunscreen. Zinc oxide and titanium dioxide larger particles and higher percentages (over 20%) besides red, yellow, and black iron oxides confer good protection against the UVB/A range and HEVL.
Heliocare Mineral Tolerance Fluid
It might fit you if you have a phototype II or I. It contains micronized zinc oxide and titanium dioxide besides the three iron oxides.
Colorless mineral powders
These powders tend to have large particles of zinc oxide and titanium dioxide in high concentrations (and lower or absent amounts of iron oxides). Due to those particles, they protect your skin appropriately against all UVB/A. And may also offer HEVL protection.
They can be a good option for reapplication (whenever you are, on top of your regular sunscreen) for any phototype. Also to simultaneously diminish blemishes (hi, oily skin areas!).
Colorescience Sunforgettable Total Protection Sheer Matte SPF30 Sunscreen Brush
Large particle mineral sunscreens
Let’s be honest! Tinted sunscreens might not be the preferred option for many. The best alternatives at the moment are mineral sunscreens with large particles (> 200 nm, non-nano). Those include creamy formulations (creams or sticks) with a more or less thick, white finish. Here I put some potentially good ones (you have to try for yourself!). Click on the links to see the ingredient lists:
Suntribe Mineral Sunscreen SPF30
Suntribe Sports Zinc Stick (Original White)
All those are good for the face, body, or localized areas when you are doing outdoor activities or at the beach, for instance. They are excellent for kids.
Suntribe Sports Zinc Stick (Retro Red)
This one features a very light reddish color, which means it contains red iron oxide. So it may protect the skin slightly better than the Original White stick.
Uriage Bariésun Mineral Stick SPF50+
To wrap up, this is a stick that includes micronized (nano) zinc oxide and titanium dioxide. However, it also has some non-nano titanium dioxide and red and yellow iron oxides.
So it’s not white (has more of a slight beige tint) nor as thick as other mineral sticks, yet it protects against UVB/A and HEVL. I use it on top of a water-resistant sunscreen on the face, hands, feet, and localized areas when I’m at the beach going in and out of the sea. It stays put and works well for me if that’s of help.
I hope you enjoyed this article.
Love and see you soon!
María
P.S. I do not currently work with any of the brands showcased above. The product links do not contain affiliates. All my recommendations are based on my professional and personal criteria.
Scientific References
1. UV-protection timer controls linkage between stress and pigmentation skin protection systems. Malcov-Brog et al., Molecular Cell, 2018; 72 (3): 444-456.
2. Free radicals induced by sunlight in different spectral regions – in vivo versus ex vivo study. Lohan SB et al., Exp Dermatol, 2016; 25 (5): 380-5.
3. Irradiation of skin with visible light induces reactive oxygen species and matrix-degrading enzymes. Liebel F et al., J Invest Dermatol, 2012; 132 (7): 1901-7.
4. Differences in visible light-induced pigmentation according to wavelenghts: a clinical and histological study in comparison with UVB. Duteil L et al., Pigment Cell Melanoma Res, 2014; 27: 822-6.
5. Melanocytes sense blue light and regulate pigmentation through Opsin-3. Regazzetti C et al., J Invest Dermatol, 2018; 138: 171-178.
6. Impact of long-wavelength UVA and visible light on melanocompetent skin. Mahmoud BH, et al., J Invest Dermatol, 2010; 130(8): 2092-2097.
7. Synergistic effects of long-wavelength ultraviolet A1 and visible light on pigmentation and erythema. Kohli I et al., Br J Dermatol 2018; 178(5):1173-1180.
8. Iron oxides in novel skin care formulations attenuate blue light for enhanced protection against skin damage. Bernstein EF et al., J Cosmet Dermatol, 2021; 20(2):532-537.
9. Near-visible light and UV photoprotection in the treatment of melasma: a double-blind randomized trial. Castanedo-Cazares JP et al., Photodermatol Photoimmunol Photomed, 2014; 30(1): 35-42.
10. A randomized, double-blinded, placebo-controlled trial of oral Polypodium leucotomos extract as an adjunct to sunscreen in the treatment of melasma. Ahmed AM et al., JAMA Dermatol, 2013; 149(8):981-3.
María Monterrubio 
2 responses to “How much does blue light hurt your skin?”
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[…] Melasma happens in people whose skin does tan in the sun (you might never experience it if your skin is very fair) and can be very persistent. Pro-inflammatory molecules released in the skin upon UV, infrared and blue light exposure from the sun make it get worse (you can learn more about the impact of blue light and sunlight on the skin in one of my previous posts, here). […]
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