Photoaging

While genetics play a significant role, the development of wrinkles is highly dependent on the amount of sun exposure.

Photoaging is a separate process and largely involves damage to the collagen and elastin fibers in the skin.

The lines apparent on mature skin, especially for those who spend a considerable amount of time outdoors, is a consequence of oxidative damage due to overexposure to ultraviolet (UV) sunlight. Sun tanning is a response to the damaging effects of ultraviolet radiation. UV sunlight includes UVA (responsible for tanning, wrinkling, and melanoma), and UVB (responsible for sunburn and basal and squamous cell carcinoma).

The amount of photoaging that develops depends on a person’s skin colour, and their history of long-term or intense sun exposure. People with fair skin who have a history of sun exposure develop more signs of photoaging than those with dark skin. In the darkest skin, the signs of photoaging are usually limited to fine wrinkles and a blotchy complexion.

Some exposure to ultraviolet B (UVB) is necessary as it is essential for vitamin D production in the skin. However, the amount required is minuscule, and 15 minutes a day is probably sufficient even in cloudy countries. Occasional exposure to visible sunlight is believed to enhance psychological well-being. For many years the treatment of skin disorders such as psoriasis has relied on deliberate controlled exposure to solar simulated sunlight and to UVA lamps.

In spite of these benefits, the UV radiation from the sun is the environmental factor that is overall most damaging to the skin. People who haven’t been over-exposed to the sun for many years tend to have pale and unmarked skin.