SCIENCE FILE / An exploration of issues and trends affecting science, medicine and the environment : A Few Minutes of Sunlight Can Spark Aging Process, Study Says

It takes only a few minutes of sunlight to start production of chemicals that set off the aging process in skin, according to Michigan dermatologists. They said enzymes known as metalloproteinases, which are also involved in the development of cancer, arthritis and multiple sclerosis, can get out of control and destroy the collagen and elastin that keep skin looking plump and youthful.

Dr. Gary Fisher and colleagues at the University of Michigan Medical School subjected the buttocks of light-skinned volunteers to ultraviolet light from a sunlamp. Within minutes of sun exposure, they reported in Nature, the skin began producing large amounts of metalloproteinases. Levels of the skin-destroying chemicals did not fall back to normal for 48 to 72 hours.