But there is hope, says Dr. Kerry Hanson a University of Illinois researcher who developed a technique to peer into the skin and study how it is affected by ultraviolet radiation. She says the addition of anti-oxidants such as vitamins E or C may help prevent skin cancer and keep skin firm.

Hanson and her colleagues at the University of Illinois Laboratory for Fluorescence Dynamics will present their findings at the Eighth Biennial Sunscreen Symposium Sep. 13-16 in Orlando, Fla.

“Ultraviolet radiation is known to cause several forms of skin cancer, including basal cell carcinoma, squamous cell cancer and deadly melanoma,” said Hanson in a press release. “But many important questions remain, such as in which layers of the skin, and in which parts of skin cells, the initial damage occurs.”

Sunscreens with a sun protection factor of 15 can block up to 94 percent of the ultraviolet light, Hanson said, but the residual light that does penetrate the skin can create free radicals -- highly reactive molecules that can weaken or destroy cell membranes. Free radicals can also damage DNA, create age spots and wrinkles, and depress the immune system, increasing the risk of skin cancer.

To study the effects of ultraviolet radiation on free radical generation and the role this plays in skin damage, Hanson used a high-tech imaging device, called a two-photon laser fluorescence-imaging microscope. The machine produces images of the skin at varying depths after ultraviolet exposure, looking for fluorescent markers that reveal the presence of free radicals.

Using the technique, Hanson found that the stratum corneum -- the skin’s main protective barrier against environmental assault -- generated a tremendous number of free radicals when exposed to ultraviolet light.

“These free radicals caused considerable damage to both the cytoplasm (the portion of a cell outside the nucleus) and the lipid matrix (the cell membrane),” she said. “The cytoplasm of the lower epidermis was also dramatically damaged.”

In a recent study funded by the Cancer Research Foundation of America and the Skin Cancer Foundation, Hanson examined the quenching effectiveness of three anti-oxidants: vitamin E acetate, vitamin E alcohol and sodium ascorbyl phosphate (stable vitamin C).

“Vitamin C was by far the best quencher,” she said. “The best results were achieved after multiple applications of the anti-oxidants when a significant amount of vitamin C accumulated within the skin. Any free radicals that are generated will be quenched by the vitamin C stored in your skin.”

While typical sunscreens offer no protection against free radical damage, Hanson believes the addition of anti-oxidants could significantly reduce the generation of free radicals.

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