The sun's rays are not only known to improve mood - in the absence of adequate protection, the risk of skin pigmentation disorders, burns, photoaging and malignant tumors increases significantly. Ultraviolet rays are the cause of both melanomas, tumors with extremely high mortality rates, and one of the most common cancers in the world, non-melanoma skin cancer. Moreover, the latter remains the most preventable. In addition to clothing, it is possible and necessary to protect the skin from UV rays with full spectrum sunscreen, which blocks radiation of types A and B. Over the past decades, sunscreens have evolved (at least the choice has become more), but the effect of active substances, coating thickness and numbers on packages continue to raise the questions that we have tried to answer.
Text: Marina Levicheva
UVA, UVB, HEV: the rays that kill us
There are two types of rays that can harm the skin: UVB, which is responsible for redness and, if you are not careful, burns, and UVA, which penetrates deeper, accelerating the aging process and destroying the skin from the inside. Excessive exposure to each type of radiation can lead to DNA damage and skin cancer. This is why it is important to choose a broad spectrum sunscreen that blocks both UVB and UVA rays.
And then there's HEV radiation, high-frequency, high-energy light in the visible spectrum that we well know as "blue light." Scientists think that, emitted by the screens of gadgets, it can disrupt sleep and, possibly, act as a booster of damage that the sun does to our skin. The latter has led cosmetic brands to launch creams and serums aimed at protecting the skin from HEV rays. So far, unlike Sanskrins, their use is optional.
Is Sanskrin necessary in winter and in bad weather?
The highest UV index is actually observed in summer and spring. But UV radiation does not depend on temperature, so in winter and autumn, the rays can also be aggressive enough to harm the skin. It is useful to remember that beach and ski resorts require an equally high SPF. This is because water, sand and snow reflect UV rays: calm water less than 10%, sand about 15%, waves 25%, snow almost 50%.
Experts from the American Academy of Dermatology say that up to 80% of UVA rays can penetrate clouds, so protection on cloudy days definitely makes sense. Moreover, clouds of a certain type are capable of increasing the level of danger, since the rays have the opportunity to reflect from the edge of the cloud, increasing their power.
How does SPF work and do we need more
Sun Protection Factor, also known as SPF, measures how well sunscreen protects the skin. Manufacturers calculate SPF based on how long sunscreen-coated skin takes for visible damage compared to clean skin. Ideally, with SPF 30, she will redden 30 times slower than if she had no cream on at all.
According to the American Academy of Dermatology, an SPF 30 product blocks approximately 97% of solar radiation, and the higher the number, the more protection. The bad news is that no cream protects against 100% UV rays, so the difference between SPF 15, SPF 30 and SPF 50 is not that big overall.
Why a high degree of protection is dangerous
As strange as it sounds, a high SPF is not such a good idea. When Procter & Gamble tested a competitive SPF 100 product in different laboratories, they found that the actual protection that Sanskrin provides varied from SPF 37 to SPF 75. The difference in results was due to the difference in testing conditions, which, in turn, allowed suggest that different application thicknesses can have a similar effect.
In addition, foods with a high SPF often stimulate dangerous changes in sun exposure.French scientists have found that vacationers spend more time on the beach when they use SPF 30 cream instead of SPF 10 cream. It happens that people think that there will definitely not be a burn, and they forget to reapply the cream.
Should I mix two Sanskrins?
We are sure you understand that when you mix products with SPF 20 and SPF 30 you will not get SPF 50. But if you think that such a mixture protects better than two products separately, then you are wrong. At best, using two products will help maintain protection - for example, if you put on sunscreen and let it dry before makeup, and use SPF powder or spray throughout the day. If you mix two liquid products, the protection can be even less than that of the best Sanskrin - the second product will dilute its carefully thought-out formula. Not to mention the fact that the components in the composition can interact poorly with each other and generally deprive you of protection.
Oxybenzone: are Sanskrins really harmful?
Due to the fact that there is more and more talk about the need for sun protection, the degree of attention to the composition of Sanskrins is also increasing. Having looked at 12 key ingredients, the FDA concluded that the most problematic of them is oxybenzoneMostly used for its ability to effectively block UVA and UVB rays. There is evidence that oxybenzone is absorbed by the skin more than previously thought (traces have been found in urine and breast milk) and may interfere with normal hormone function (in mice, for example, it triggered a 23% increase in uterine size).
Sounds intimidating? Still would. Only here we, unlike rodents, do not eat sunscreen. In addition, new research on the topic showed that to get the same dose of oxybenzone, we would have to apply Sanskrin daily for 277 years. As for the physical Sanskrins using zinc oxide and titanium dioxide, then they do not always correspond to the SPF declared on the package and often do not provide full spectrum protection.
Can Sanskrins harm the planet?
They can, and stronger than they seem. In 2021, Hawaii will go into law banning sunscreens containing oxybenzone and octinoxate, which discolor coral reefs and interfere with their growth. And this is just the beginning, because zinc oxide appears to do the same.
What should be done to those who want to protect themselves without harm to nature? Unfortunately, there is no perfect product or method yet. In theory, this could be a full-body UV-cut swimwear, but few would agree to wear it. Realizing this, scientists in Puerto Rico are actively working to create biodegradable granules that could absorb oxybenzone from the oceans. We hope they succeed.
How much cream to apply
Research shows that most people use 25-50% of the amount of Sanskrin they actually need. At the same time, ideally, an adult should use about 30 ml of Sanskrin (the size of a glass) to cover all protruding areas of the body, and begin the procedure 15-20 minutes before going outside, so that the product has time to start working.
Researchers at King's College London have also found that a person who regularly uses SPF 50 sunscreen provides only 40% of the expected protection. That is why it is important to use products with SPF 30 and higher: theoretically, SPF 15 may be enough for us, but will we apply it in the right amount?
By the way, even those of us who pay maximum attention to sun protection miss such strategically important areas as lips and eyelids. Moreover, the experiment showed that if the participants used a separate sunscreen (and not a day or foundation with SPF as a bonus), they worked on the face 5.5% better, and the area around the eyes - 6.9% better.
Form factor and shelf life
If we consider a lotion with SPF 30 and a spray with SPF 30, then in terms of effectiveness in the laboratory, they will be exactly the same.However, cream products are easier to apply in sufficient volume, as a spray tends to spray a very thin layer of the product onto the skin. Plus, in a spray situation, there is a risk of inhaling minerals and chemicals in the air.
The shelf life of Sanskrins is limited - it is about three years in a closed bottle and about a year (look for exact information on the package) after opening. But if you have to choose between expired sunscreen and no sunscreen, the former is always better. Yes, the active ingredients in an expired product will not work at their full strength, but they will still work.
Why gadgets, stickers, and apps are pointless
Most sun protection devices, including UV Sense (L'Oréal), Microsoft Band and Sunsprite, work according to the following principle: when a person goes outside, the gadget registers the amount of UV rays with a dosimeter, correlating this with information about the skin type and the presence of dermatological diseases and makes recommendations. However, the devices give average results, without considering that UVB rays are stronger than UVA rays. Also, the indicators may depend on the location of the gadget on the body.
There are also stickers and smartphone apps. The former use UV-sensitive ink that changes color under the influence of UV rays - that's all, so that at most they can remind you that it's time to update the sunscreen or hide in the shade. In this sense, applications such as Ultraviolet ~ UV Index that analyze the UV index at a given point are even more useful. They, as a rule, also take into account the characteristics and color of the skin, and then give recommendations on what needs to be done to reduce the risks (for example, wear a hat or apply SPF 30 cream).
So why does science think that none of this works? Because each of the devices assumes the presence of a base tan, after which the user enters the "danger zone". Only, as is well known, such a tan does not exist.
What else does the market offer
You can find, for example, sunscreen tablets, the benefits of which (as it were) include increasing the level of the skin's natural protection against UV rays. But antioxidant supplements certainly fail to protect against melanoma or prevent photoaging of the skin, which endangers the health of the people who use them. These dietary supplements contain only one element with minimal scientific support - Polypodium leuctomos leaf extract. One study has shown that it can reduce redness caused by UV radiation. But, obviously, it is impossible to talk about any protection here.
The future: salmon semen, artificial melanin and nanoparticles
It is clear that there is no perfect way to protect the skin from UV rays. But scientists continue to try, using all the possibilities at their disposal. So, they managed to create a material similar to melanin - a natural pigment that protects human skin from ultraviolet radiation. The material, which was obtained in the laboratory, promises to mix well with water, so that cosmetic brands can easily integrate it into the new generation of Sanskrin formulas.
There is also an option for the lazy - sanskrin, which will be enough to apply once in a lifetime. Taking DNA from salmon sperm, the scientists created a "cream" on its basis, which forms a thin protective film when applied. As a result, the film was not only able to block 90% of UVB rays and 20% of UVA rays, but under the influence of ultraviolet radiation it became stronger and stronger due to an increase in the density of crosslinking of molecules. A nice bonus? The film has been found to effectively retain moisture in the skin.
It is also possible that soon we will be using a sunscreen based on nanoparticles with a prolonged release, which will not be able to penetrate into the deep layers of the skin. Filled with SPF balls, the researchers explain, will form a "thin coat" on the surface, equal to that of modern Sanskrins. It is important that the creation of such products requires fewer chemicals - only 5%.
And then there are cyanobacteria that could be a safer alternative to modern Sanskrins by reducing the risk of side effects, including allergic reactions and hormonal imbalances. And at the same time to prevent the ingress of chemicals into the environment, which is equally important.
5 important steps for sun protection
Avoid the sun during peak hours - from 10:00 to 14:00, even on cloudy days.
Protect your skin not only with cream, but also with clothes. Experiments have shown that dense fabrics such as denim, wool and polyester protect the skin significantly better than cotton and linen. And for hikes and picnics, UPF fabrics, specially treated to protect from the sun, are an excellent option.
Reapply the cream every two hours if you are still outside.
Always use waterproof products on the beach. But remember that these remedies also last up to 40 minutes during swimming or profuse sweating, so they need to be updated anyway.
Follow the rules even if you have dark skin. The myth that she needs less protection has led to the fact that the survival rates for skin cancer are the lowest in people with dark skin.
Photos: Dmitri Stalnuhhin - stock.adobe.com, photomelon - stock.adobe.com, puhhha - stock.adobe.com