In a study published in October 2016(1), a group of scientists and doctors suggested that individuals should accumulate sufficient sun exposure, and specifically what they call “non burning sun exposure”, to maximize their vitamin D intake and trigger a natural sun protection process called photo-adaptation. Let’s get things straight here: there’s mindful and reasonable, non-burning sun exposure vs prolonged, unreasonable and burning sun exposure. The first situation is what scientists consider as beneficial, the second is obviously considered dangerous and harmful.
Melanin, a natural sunscreen?
Here is what research tell us: human skin has developed two main defense mechanisms to guard against the damaging effects of UV: epidermal thickening and the stimulation of melanin synthesis, more important with regard to photo-protection. Several epidemiological as well as experimental data demonstrates the important role of melanin in photo-protection, and not merely as a sunscreen(2).
Still according to scientific research, the efficacy of melanin as a sunscreen is assumed to be about 1.5-2.0 sun protective factors (SPF); possibly as high as 4 SPF, implying that melanin absorbs 50% to 75% of UV radiation. An SPF of 2 means the doubling of protection of the skin against sunburn. Dark skin, which contains more eumelanin than fair skin is better protected against UV-induced damage, and eumelanin is thought to be superior to pheomelanin in its photo-protective properties (the darker your skin, the more eumelanin you have compared to pheomelanin, and vice versa). Melanin in black skin is considered more effective compared to white skin in inhibiting UVB radiation from penetrating. While black epidermis allows only 7.4% of UVB and 17.5% of UVA to penetrate, 24% UVB and 55% UVA pass through White skin(3).
Why does melanin stimulation matter?
But why stimulating melanin actually matters? Photo-adaptation, starting with the stimulation of melanin, is a natural attribute of our body, an amazing machine where nothing happens randomly.
Photo-adaptation is specifically meant to help the skin make the most of sporadic and reasonable amount of time spent in the sun: allowing the synthesis of vitamin D while fending off the harmful effects of UV rays, both UVB and UVA. Since 80% of our time outside year-round is sporadic and passive, most likely without sunscreen (this will be treated in a next article), we should actually be happy to know that our skin is equipped to perfectly deal with it: not only protect us, but also get a health benefit out of it. But for this protection to happen, we need to intentionally spend some time outdoors when UVBs are around (spring-summer mostly in the US), in order to stimulate our melanin. Or we can use Skinergies Incidental Sun Smart Serum, that mimics the action of sunlight ad stimulates the melanin. Perfect to use through the fall-winter, and make the skin “sun -ready” when spring comes.
(1) The risks and benefits of sun exposure 2016. David G. Hoela, Marianne Berwickb, Frank R. de Gruijlc, and Michael F. Holick
(2) Photoprotection by melanin--a comparison of black and Caucasian skin. Kaidbey KH, Agin PP, Sayre RM, Kligman AM J Am Acad Dermatol. 1979 Sep; 1(3):249-60
(3) Skin cancer in African Americans. Halder RM, Bridgeman-Shah S Cancer. 1995 Jan 15; 75(2 Suppl):667-73.