How does tanning function as a protective measure for the skin?

Tanning serves as a protective measure for the skin primarily by stimulating the production of melanin. When the skin is exposed to ultraviolet (UV) radiation from the sun or tanning devices, it responds by increasing melanin production, which is the pigment responsible for skin color. This increased melanin acts as a natural sunscreen, helping to absorb and deflect harmful UV rays to protect deeper layers of skin from damage. This protective response is crucial because it reduces the risk of UV-induced skin damage, including sunburn and long-term issues such as skin cancer.

Though thickening the skin and healing sunburn might seem related to skin protection, they do not directly result from the tanning process itself. The destruction of skin cells would also be counterintuitive to protective measures, as skin cells play important roles in overall skin health and function.