Escape from the laptop: Does blue light really damage your skin?
Dry air, hard water, ultraviolet radiation, soap - a list of what complicates the life of the skin, frankly, rather big. Recently, however, they started talking about the fact that the blue light from the screens of smartphones and computers also acts on it destructively. Is it really worth worrying about the new adversity? We understand what blue light is and whether it can threaten the well-being of the skin.
Text: Flu Petrova
What is blue light
Visible light is the range of electromagnetic radiation that the human eye perceives. What is next to this range on the scale of the spectrum (on the one hand, infrared light, and on the other ultraviolet), we no longer see: our vision catches only the wavelength of 380-700 nanometers. In this not very long gap, all the colors of the rainbow are laid, and together they give what we perceive as white light. When a sunbeam falls on a grandmother's crystal chandelier in the spring, it shatters into rainbow highlights - this is the visible spectrum.
The wavelength of blue light is 380-500 nm (technically, this is blue and violet light, but more often they are combined). Light has two more characteristics: frequency and energy. Blue light has the shortest wave of visible, therefore its frequency is the highest - that is, a point on the wave passes a fixed control point in a second the most number of times. The energy of blue light is also the highest, which is why it is also called HEV-light, from "high energy visible" - high-energy blue light. HEV-light makes the sky blue, it is in the light of the monitors of smartphones and tablets, LED-TVs and LEDs - and also publications and brands vied with one another that it harms the skin.
Visible blue light on the range turns into ultraviolet. It is for protection from it that we use Sanskrins: we say "sun" - we hear "ultraviolet". In this case, on the scale of the spectrum, the boundary between ultraviolet and visible light lies where the visible eye ends. Until recently, no one tried and did not even think to link the position on this scale with the degree of influence on the skin.
How blue light affects the skin
Blue light is wherever visible light is. When we discuss the harm of blue light, we cannot only talk about smartphones and laptops: the sun and electricity also emit it. In a sense, the blue light of gadgets harms any skin: it suppresses melatonin production, which means it knocks off a circadian rhythm - as a result, a person does not get enough sleep and does not feel well, and therefore cannot boast of freshness.
Until recently, photodermatological studies were mainly concerned with the ultraviolet region of the spectrum, rather than the visible. There are not so many studies of the effects of HEV-light on the skin of the face - and those that are, emphasize that the theme of the effect of blue light on the skin is poorly understood. It is difficult to rely on surveying companies interested in making a profit from the sale of cosmetics. For example, in a study commissioned by the cosmetics company Lipo Chemicals in 2013, it was argued that HEV light acts as destructive as UVA and UVB rays (talking about blue light with different wavelengths), and even worse: according to their data, it penetrates the skin of the face deeper than the invisible ultraviolet light.
To seize a dose, sufficient for hyperpigmentation from the blue screen, is difficult
In 2014, researchers compared the ability of blue visible light (with a wavelength of 415 nm) to cause pigmentation with the same properties of red light (wavelength of 630 nm), as well as mixed variants. Control areas of the skin were irradiated with UVB rays or not irradiated at all. The study showed that on the skin of III and IV types - that is, relatively dark, prone to tanning and olive - the effect of blue light really leads to pigmentation, and the skin of type IV suffers more.
The pigmentation that appeared under the influence of blue light even after three months was brighter than the pigmentation in the control area, which was irradiated with ultraviolet light. However, according to the results of the study, the destruction of keratinocytes, which form the skin protective barrier, and p53 protein (which is an anti-oncogene) in the area that was irradiated with UVB rays, was still more intense. In general, according to the findings of scientists, hyperpigmentation under the influence of blue light has a slightly different nature than hyperpigmentation of the UV character: since DNA is not damaged, p53 is also not activated.
A 2015 study shows that carotenoids in the skin disintegrate in the same way as under the influence of visible blue light, just like under the influence of ultraviolet and infrared rays. The breakdown of carotenoids is indirectly associated with the formation of free radicals: in theory, carotenoids are the first of the antioxidants that protect the skin from them. In large doses, visible blue light can be an unfavorable factor for the skin, the scientists conclude.
Does it make sense in special cosmetics
In the end, there is only one conclusion: if you take a lot of blue light, it can obviously arrange a relatively dark skin with temporary hyperpigmentation without long-term consequences. The scale of the problem depends on how much light you need to take. Lab Muffin blog author and chemist Michel compares doses used in experiments with visible blue light, sun light and screen light. Let's make a reservation that the numbers, of course, are very conditional: the amount of blue light from the sun depends on the time of year and the place where you are. Information on the screens is also not entirely accurate.
Michel notes: in experiments, skin types III and IV produced hyperpigmentation at a dose of light energy with a blue tint of 40 joules per square centimeter. The same dose of visible light can be obtained in 13.3 minutes in the summer in Texas. Or blue for 40 minutes in southern Europe at summer afternoon.
Now take the iMac. At a distance of 60 cm from it, studying the text on a white background, you get 40 J / cm² for 1.28 days. At the same time, the iMac screen is one of the brightest. So, to get the same dose of blue light from the screen of the Dell XPS 13, you have to sit for it 3.43 days. From the screen of the Samsung Galaxy S7 smartphone at a distance of 23 cm at 40% brightness, the required dose of “killer” blue can be obtained in six and a half days. From here a conclusion: to seize a dose, sufficient for hyperpigmentation from the blue screen, is difficult.
The same blue light and ultraviolet light are part of phototherapy for skin diseases.
It turns out that all that we can do is read more often from paper, not from the tablet, and not flipping through the tape of friends, if there is nothing interesting there. And we can slightly support our skin with cosmetics, especially if it belongs to type III or IV. According to one study, zinc oxide from HEV-light protects poorly despite the fact that this is a physical filter - it all depends on the size of the particles in the composition. But the colors of the visible spectrum successfully absorbs iron oxide. As part of cosmetics, it can be listed not only as "iron oxide", "black iron oxide"; "CI pigment brown 7"; "CI 77489"; "CI 77491"; "CI 77492"; "CI 77499"; "ferric oxide". He is also added to decorative cosmetics, where he often appears as a pigment. And GoodGuide, among other products with iron oxide, offers anti-acne products with a tinting effect, such as Clearasil Daily Clear Tinted Acne Treatment Cream. There is oxide in some sunscreens with physical filters: its shade can be close to the natural color of the skin, due to which it eliminates the "whitening" of titanium oxide. The effect of oxides on the skin, however, has yet to be investigated in detail.
Instead of covering your face from blue light, you can go through compensation. Blue-purple color is suspected of increasing the number of free radicals - in this case, you can use any tool with antioxidants. Some cosmetic companies, seeing a new market niche, rushed to put their funds there. For example, Dr Sebagh Supreme Day Cream is positioned as a moisturizing cream with protection simultaneously from LED-, HEV-, UVA- and UVB-rays. The tool, according to the formula, contains a component that protects against photo-aging and a complex of antioxidants (and moisturizes well). That is, in general, there is nothing revolutionary in it.
What else is needed blue light
The same blue light and ultraviolet light are part of phototherapy that treats skin diseases or corrects its features. Of course, in well-calculated doses. Ultraviolet irradiation in different versions is used in conditions like eczema and psoriasis; according to studies, it also helps reduce the severity of vitiligo. For example, UVA radiation in combination with a photosensitizing drug is PUVA therapy, it is also called photochemotherapy. Meanwhile, the risks of treatment with ultraviolet radiation are the same as with ultraviolet irradiation in general: premature aging of the skin, redness, the need to protect the eyes during treatment and so on. Phototherapy of this kind is also used for acne - visible blue light with a wavelength of 400-470 nm exhibits antimicrobial properties. The mechanism of the phenomenon is not yet completely clear: it is assumed that blue light acts on porphyrins (substances capable of absorbing the energy of light) in microbes. Under irradiation, porphyrins are activated, affect the release of oxygen, and it damages and destroys microbes.
In a sense, blue light may even be more effective than antibiotics - namely, that it is more difficult for microbes to develop resistance to it. The efficacy of blue light was tested on organisms with gastric infection Helicobacter pylori (the name of this bacterium was heard by everyone suffering from gastritis), and it worked. More importantly, Acne vulgaris is treated with blue light, common eels, in the light and medium stages - most often it turns out quite well (here is a good example). Thus, the twelve-week study of 2018 showed excellent results, the effectiveness of treatment ranged from 58.3% at the easy stage. In this case, the result was maintained for a long time, but there were few side effects. So that blue light, which we are recommended to defend against today, brings one benefit, if applied correctly.
Photo: Kirill Zhuravlyov - stock.adobe.com, F16-ISO100 - stock.adobe.com, by-studio - stock.adobe.com
