We all know about the health risks associated with excessive sun exposure, such as skin cancers, cataracts, age-related macular degeneration (AMD), and accelerated skin aging, including wrinkles and sunspots. However, the right amount of sun exposure also positively affects our mood, helps preserve bone health, and facilitates vitamin D synthesis, strengthening our immune system.
But why are the sun’s rays potentially dangerous? How does sun exposure affect our skin? And how can you achieve a beautiful golden complexion while protecting your skin?
We have all the answers for you, along with expert beauty advice from our Anne Semonin specialists!
1. The relationship between skin and the sun is a question of wavelengths
There are three categories of solar radiation: infrared (55%), visible light (42%), and ultraviolet (3%). In the context of skin aging and the development of skin cancers, the role of infrared radiation is considered relatively minor. Similarly, while visible light may play a part in sun allergies, its impact on skin aging is relatively insignificant.
This leaves us with UV radiation, the most concerning category. UV radiation is the most potent and harmful type of radiation. It is divided into UVA (long UV), UVB (short UV), and UVC. The shorter the wavelength, the more damaging it is for the skin as it penetrates deeper into the epidermis.
Additional info : UVC rays are highly energetic and pose the greatest danger. However, their wavelength of 100-280 nm (compared to 400-315 nm for UVA and 315-280 nm for UVB) prevents them from penetrating the ozone layer and reaching the Earth's surface. Only radiation with wavelengths longer than 280 nm can achieve this.
2. UVA and UVB Rays: Understanding Their Effects
UVA rays constitute nearly 95% of the UV radiation that reaches the Earth's surface. Most of these can penetrate the epidermis, giving you that lovely tan following sun exposure. However, they also contribute to skin aging and the formation of wrinkles.
UVB rays only permeate the superficial layers of the skin and are predominantly absorbed by its outermost layer. They induce a long-lasting tan with a delay, appearing two or three days after exposure. Unfortunately, UVB rays are also the culprits behind sunburn and, in the long run, accelerated skin aging. They are also responsible for the development of skin cancer. On the plus side, UVB rays play an important role in vitamin D synthesis.
Additional info : UV radiation stimulates melanin production, a brown pigment that safeguards the skin against photoaging. This melanin is what gives your skin its tan. In case of excessive sun exposure, the skin's defense mechanism increases melanin production. However, sunspots may appear when melanin becomes clumped or produced in high concentrations.
3. Discover the sun protection ingredients in cosmetics
Four organic filters and thirty mineral filters protect against UV rays in cosmetics. Mineral (or inorganic) filters penetrate the epidermis to absorb the sun’s UV rays. Organic filters, including titanium dioxide, remain on the skin's surface and reflect UV rays. The titanium dioxide (which is also a whitening agent) in certain sun protection creams leaves a white finish on the skin after application.
Sun protection products may or may not combine both types of sun filters, each with characteristics that influence the products' appearance, application, and protection. Organic filters, usually fluid and non-sticky, contribute to a smoother application and texture of the product. However, their effectiveness relies on absorption into the epidermis, which takes around 30 minutes after application. The application of mineral filters, on the other hand, provides immediate protection.
Additional info : The term chemical filters is often used for organic filters. Organic and inorganic filters, however, are derived from chemical processes and are, therefore, chemical filters.