The skin is our largest organ – especially in summer it needs a lot of protection. But which is actually the most effective?
Clearly: In summer we have to protect our skin from UV rays. The sun not only causes painful sunburns, it can also cause long-term damage. But which sun protection is best suited? Which texture suits my skin type? And which sun protection factor should I use? Dermatologist and author Prof. Michaela Axt-Gadermann (current book "Naturally! Beautiful skin") provides answers to the most important questions about sun protection.
Which sun protection factor do I need?
When choosing the perfect sun protection, you should be guided by your own light type, i.e. skin type, and the UV index. "Skin type 1 is the Irish-Celtic type, which actually does not turn brown and gets sunburn very quickly. Light type 4 is the more Mediterranean type, which tans quickly and is largely protected from sunburn," explains Professor Axt-Gadermann. The UV index is a scale from 1 to 10 introduced by the World Health Organization (WHO) – the rule is: the higher the value, the faster sunburn occurs.
Which sun protection factor is required can easily be calculated with these two factors. Use a quick Google search to call up the current UV index and multiply it according to the light type: for type 1 times four, type 2 times three and so on. A concrete example: If a person with very fair skin wants to go into the sun on a day with UV index 7, you multiply seven times four and get 28. The appropriate sun protection factor in this case would be the common SPF 30.
This also applies to cloudy days and sunbathing in the shade. According to the dermatologist, UV radiation can even be stronger here than in a clear sky, since sunlight is directed in different directions by the water droplets or ice crystals in the clouds. And shadows or clothing do not provide complete protection. When wet, the UV permeability of textiles even increases.
How long can I stay in the sun without sunscreen?
Each skin has an individual protection time (ESZ), i.e. a period of time in which you can expose the skin to the sun without causing sunburn. "The self-protection time varies greatly and depends on the skin type and the intensity of the sun," explains Michaela Axt-Gadermann. In this country in summer it would be between five minutes for very light-skinned types and 45 minutes for dark-skinned ones. "However, you should never fully exploit your own protection time, so it is better to use a slightly higher sun protection factor."
Those who stay longer in the sun or dry themselves after bathing have to apply cream. According to the dermatologist, with a single use of a sun protection product after a four-hour stay in the sun, only around 60 percent are left. Therefore, you should apply cream after four hours at the latest, at the earliest if you have dried yourself off with a towel. "When drying, a large part of the sunscreen is always removed," says Axt-Gadermann.
Cream, lotion or gel? Which consistency works better?
Sun protection is available in a wide variety of forms and consistencies. The dermatologist advises using a lotion for the body, as it can be distributed well, even liquid, transparent products such as oils are good.
A cream is ideal for dry skin on the face, and a gel should be used for oily, seborrheic skin. Those who tend to blemishes develop a so-called "Mallorca acne" more often. "This is often caused by emulsifiers in the sun's milk. Fat-free sun protection gels do not need any emulsifiers and are therefore usually well tolerated," said Axt-Gadermann.
Do not rub in sunscreen too intensely
But it is also important to apply the sun protection sufficiently thick before sunbathing. "Most people definitely wear sunscreen too thin," says the dermatologist. In order to adequately protect the entire body of an adult from UV light, 30 milliliters or about six teaspoons of sunscreen are necessary – this corresponds to a whole handful of sunscreen lotion.
Many believe that the more thoroughly the sunscreen is massaged into the skin when applied, the better the sun protection. But the opposite is the case. If the sunscreen is rubbed intensively on the skin, it loses a large part of its protective effect – this has now been proven in a British study. Reason: The massaged cream settles in skin wrinkles and pores. Better protection is provided by an even film that is only distributed on the skin but not rubbed in.
With nutrition: sun protection from the inside
In addition to sun protection on the skin, certain types of food can also be used to create a kind of "sun protection from the inside". Green tea, tomatoes and tomato products, carrots, watermelon and pink grapefruit make the skin more resistant to UV rays. And even dark chocolate can help with regular consumption. Michaela Axt-Gadermann explains that this can only achieve a sun protection factor of 4, but it offers daily, waterproof "basic sun protection" that works from head to toe and demonstrably contributes to delaying sun-induced skin aging.
Probiotics also protect the skin from the inside. If certain bacteria are taken up to two weeks before sunbathing, damage by UV light can be mitigated: "Wrinkling, sensitivity to light and sun damage can be reduced by probiotic bacteria and the intake often has a favorable effect on a sun allergy."