Does 'crab red' turn into tan?

77% of the Spanish population does not know what the SPF number written on sun lotions means, according to a recent study carried out by Avène Laboratories. SPF creams protect the skin from ultraviolet B (UV-B) rays, the main causes of sunburn; however, research has shown that both ultraviolet A (UV-A) and UV-B rays can contribute to skin cancers and premature aging of the skin.

And what do those mysterious initials mean? SPF stands for 'sun protection factor'; and the figure, the time that can be exposed to the sun. Given the dates, we went to the specialists to shed light on a few erroneous beliefs, and do not be part of that 62% who think that an SPF 30 protects twice as much as an SPF 15. When in doubt, Antonio Licitra, medical specialist aesthetics of the Med-Estetic clinic, recommends using protection: "Always when going outside, even on cloudy days."

1. An SPF 30 protects twice as much as an SPF 15: False. There is still no miracle cream that protects 24 hours a day. "Just because you buy SPF 100 doesn't mean you're 100% protected," says researcher Roopal Kundu: "Staying out of the sun is the only way to guarantee 100% protection. "Every degree of SPF (6, 15 , 20, 30 or 50) refers to the amount of time that the skin is protected" they explain in Douglas Sun, the sun care division of the cosmetics and perfumery chain. The numbers on the bottle indicate minutes. Depending on the minutes Multiply by the number on the bottle that it takes time to burn without protection, so you know how long you are protected and when you need to reapply the cream.

“For example, if it takes you 20 minutes to burn and you apply an SPF 15 sunscreen, you'll be protected for about 300 minutes, or five hours (SPF 15 x 20 minutes = 300 minutes). A person with lightly pigmented skin who burns in 10 minutes would be protected for only about 2.5 hours (SPF 15 x 10 minutes = 150 minutes), as estimated by the American Skin Association.

Of course, these calculations are individual. Some people start to burn at minute one and others at 10. The degree of SPF multiplies the protection time by as many times as indicated. If you don't know your factor, doing a test of how long it takes to burn is very foolhardy. "It is convenient to be prudent during the first days of sun and use high protection factors on repeated occasions," warns the specialist Ricardo Vicario, from Clínicas Vicario. No more.

2. As soon as you apply the cream you are protected: Not always. José Vicente Lajo, from the Lajo Plaza Medical Center, specifies: "If we use a chemical filter, it is also important to know that it takes about 20 minutes to generate protection, while if we use a physical filter, which thanks to its density creates a screen that does not let the sun penetrate, it is immediate”. The physical filters of the creams are those that contain zinc oxide and reflect solar radiation, while the chemical ones absorb UVA and UVB rays, protecting the deeper layers of the skin, according to Lajo.

3. If you put on two creams, sun protection adds up: False. If you apply an SPF 50 cream and add another SPF 30, the result will not be SPF 80. Nor if you apply more. Ideally, do it with the correct frequency (the multiplication above will give you the frequency). “To protect yourself more, you have to do it more frequently. Not with more quantity or putting cream on cream”, subscribes Elaine Ferreira, from the Prima-Derm group.

4. After sun cream you can apply makeup: False. "You have to wait between 5 and 10 minutes for the protector to be well absorbed by the skin before applying makeup," says Ferreira. If not, when passing the brush or sponge I would remove it, leaving the area without protection. Another option advocated by Paloma Cornejo Navarro, head of the Dermatology unit of the Laser Medical Institute (IML), is to use make-up with SPF up to 50 and tinted creams up to SPF 90. "In addition, the physical filters of the Makeup pigments are quite safe and help prevent melasma. Of course, you have to touch up every 3-4 hours because they lose efficiency ”, he adds.

5. If you are already tanned, you will not burn: False. "30% of the Spanish population does not correctly renew sun protection", according to data from Avène. Leonor Prieto, scientific director of La Roche-Posay Laboratories, insists: "The skin, even when brown, needs to be protected in the same way, because the SPF not only defends externally, but also internally, preventing burns, cellular alterations and the possible appearance of moles, freckles, or melanomas”.

6. If you are pregnant you will have spots: False. Not all pregnant women have spots nor do the spots come out just because of the pregnancy, although there is a greater predisposition if they sunbathe. "Sun exposure increases the chances of melasma appearing during pregnancy," says Aurora Rodríguez Huergo, from Hedonai. During pregnancy, hormonal changes "give rise to a greater activation of melanocytes which, together with sun exposure, favors the appearance of the spots that we call melasma, chloasma or pregnant cloth" adds Prieto.

Find out your phototype

In the case of not knowing how long it takes our skin to burn naturally, there are generalized tables that divide the world population into six phototypes: I, II, III, IV, V and VI. Antonio Licitra, from Med-Estetic, clarifies: "Phototype I is the whitest and most sensitive to the sun and phototype VI is black skin, with more resistance to burning." The first thing is to identify the phototype and then multiply the number of the bottle by the number of the phototype. For example: with a phototype II and with a protector 20 (2x20 = 40 ), you can only be exposed for 40 minutes, while with a phototype IV (4x20 = 80 ), you can be in the sun for 80 minutes." Paloma Cornejo, head of the IML Dermatology unit, tells us in this table how to easily identify our phototype according to the characteristics of our skin:

Phototype I:

Phototype II:

Phototype III:

Phototype IV

Phototype V

Phototype VI

Melasmas are more or less dark brown spots, smooth, with irregular edges and usually appear in the middle area of ​​the face (barcode, cheeks and forehead). In addition, the darker our phototype is, the more tendency we have for melasma to appear and in many cases it does not disappear after pregnancy. But they can be avoided: “There are epidemiological studies that show that if we apply a high protection sunscreen (SPF 50+ and very high UVA protection) we can avoid up to 97% of its appearance, its intensity and its permanence in the skin. skin”, says the Avène specialist.

7. Food supplements have the same effect as the cream: False. Beta-carotene (or provitamin A) pills provide vitamins to assimilate the sun's rays and achieve a faster tan. "But they do not create the protective film that the skin needs so that the sun does not damage it," recalls Vicario. Food can complement the preparation of the skin for the sun, as well as prevent premature aging. "At this time it is interesting increase the amount of foods rich in lycopene and beta-carotene such as tomatoes, watermelons or carrots, which stimulate the production of collagen, which makes our dermis recover before the effects of the sun," says Vicario. Nuts also help to increase up to 25% sun protection applied to the skin, while seasonal fruit such as cherry, apricot, melon or peach stimulate melanin, which increases healthy tanning.

8. Green tea protects: Doubtful. Various studies have shown (in animals) that topical treatment or oral consumption of green tea polyphenols protects the skin from the harmful and cancerous effects of UVA rays. Among them, the one published in the National Library of Medicine of the National Institute of Health in the US Epicatechin derivatives, commonly called polyphenols, present in green tea, have antioxidant, anti-inflammatory and anticancer properties.

9. On gray days you can do without protection: False. Clouds can even increase radiation since humidity creates a reflective effect, so on cloudy and cold days, even if we don't see the sun, it's important to be protected. "On cold days, UVA rays (responsible for immediate pigmentation) may decrease a bit, but UVB rays (the main causes of burns and melanomas) remain," says Rodríguez Huergo.

10. After 'crab' red comes tan tan: False. It is the typical self-consolation phrase after a day at the beach in which we have burned ourselves. However, burns due to lack of protection affect the superficial layers of the skin, causing us to peel quickly and we already have the memory of the burn at the cellular level.

11. With sunscreen I don't get a tan: False. "Although it may seem that a person is tanning less, in reality they are gradually acquiring color without burning the skin, thus ensuring a longer duration of this tan," says Prieto.

12. If it says "water resistant" you can swim without concern: False. “We say that a product is 'water resistant' when after two 20-minute baths it continues to maintain at least 70% of the indicated protection factor. And the 'very resistant to water' (water proof) allow double, 4 baths of 20 minutes”, adds Leonor Prieto, who qualifies: “If you do water sports it is advisable to wear appropriate clothing and reapply the product in exposed areas after a long bath.

13. Babies can be exposed to the sun with sunscreen: False. With the little ones, extreme precautions must be taken. The skin of babies and children up to three years of age is immature and their defense system is not as active. This means that it is a thinner, more permeable and delicate skin. Dermatologists and pediatricians recommend not exposing babies or children under that age directly to the sun. But even without direct exposure, the reflection of the sun can accumulate significant radiation. "That is why physical protection is recommended (hats, shirts, umbrellas) and from six months on, apply a specific sunscreen for babies or children in uncovered areas," adds Prieto. The WHO and the scientific community establish that repeated burns in childhood are a risk factor for the development of skin cancer in adulthood. Hence the importance of avoiding exposure as much as possible and protecting them with all available means.

14. Brown skins need less sun protection: False. A pale skin burns before a brunette, yes. But the fact that a brown skin does not burn does not mean that the sun does not exert the same photoaging on it as on a lighter one. A recent study by Douglas Sun emphasizes: "UVA and UVB rays penetrate all skins equally, affecting the internal and cellular level." Sun-induced immunosuppression, photoaging or skin cancer also affects colored skin.

15. Sun protection prevents you from assimilating vitamin D: False. "If we carry out a normal life with 10-15 minutes of daily walk in the open air, there are always areas that we have uncovered through which we receive ultraviolet radiation capable of favoring the synthesis of necessary vitamin D (important for absorbing calcium)" assures Antonio lycitra. In general terms, direct sun exposure is not recommended. In particular cases of vitamin D deficiency or insufficiency, it will be the doctor who advises on how and how long to be exposed. There are certain pathologies or situations in which it may be advisable to sunbathe, but this already falls within the therapeutic scheme and it must be the dermatologist, pediatrician or specialist who prescribes and controls the conditions. “We should never do it on our own, even if we have heard that the sun improves acne, psoriasis, eczema or sun allergies”, concludes Leonor Prieto.

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