Aging Skin -- The Sun and Skin Aging -- Harmful Rays

The sun emits two types of ultraviolet (UV) radiation -- UVB and UVA rays -- that are responsible for photoaging and skin cancer.

• UVB rays have a shorter wavelength than UVA rays but can still penetrate the surface layers of skin, causing sunburns and damage to DNA.
• UVA rays have a longer wavelength and penetrate more deeply into the skin, contributing to the formation of free radicals, which damage skin structures and DNA. This process alters the breakdown and regeneration of collagen, making skin appear tougher, thicker, and more wrinkled. Just a few minutes of exposure will begin to alter collagen production.

Although researchers at one time thought only UVA rays contribute to skin cancer risk, research now reveals that both UVB and UVA rays play a role. Both types of rays damage skin. Skin cancer can occur when, in attempting to repair this damage, the skin's regenerative process fails to work correctly.

Tanning Equals Damage
Exposure to UVA rays causes tanning, but tans are an indication of skin injury. Tans result from an overproduction of melanin by the skin in an effort to protect the body from the sun's harmful radiation. There is no such thing as a healthy tan.