Antioxidants: Truth or hype?

Popular ingredients may not improve wrinkles
Feb 1, 2008
By:Lisette Hilton
Dermatology Times

Key Points
Best antioxidant is sunscreen, expert says
Antioxidants can prevent damage, but may not correct
Some ingredients are photoprotective

National report — Zoe Diana Draelos, M.D., says the best antioxidant available today is a sunscreen.

“All the others are really secondary,” Dr. Draelos says. “Sunscreens function as antioxidants just by protecting the skin from the sun.”

While antioxidants have a place in prevention, treatment is another matter, according to James Spencer, M.D., M.S., dermatologist, professor of clinical dermatology, Mount Sinai School of Medicine in New York, and in private practice in St. Petersburg, Fla.

“When added to sunscreens, they can help prevent sunburns, for example. There is good evidence that they can prevent skin cancer,” Dr. Spencer tells Dermatology Times.

Dr. Spencer
“But what they are often being sold as are beauty treatments — wrinkle treatments. There is very little evidence that that is true.

“So, there is good evidence that it will prevent you from getting wrinkles, but not so good that they will treat them,” he says.

Proven benefits

Dr. Draelos
Dr. Draelos, who practices in Highpoint, N.C., and is editor of the Journal of Cosmetic Dermatology, says the first thing antioxidants do when added to topicals is preserve the products.

“All products that contain lipids have to be protected against oxidative damage,” Dr. Draelos says.

On the prevention of sunburns, photodamage and skin cancer front, Dr. Spencer says many antioxidants have been studied, and some have shown efficacy, such as green tea, resveratrol from grapes and genistein from soy beans.

Dr. Matsui
“These things help prevent cancer. But treatment and prevention are different things,” Dr. Spencer says.

UV exposure generates considerable oxidative stress; so, antioxidants have naturally been candidates for prevention of photoaging and actinic damage.

There have been a limited number of published studies in human subjects that address this question, however, says Mary S. Matsui, Ph.D., executive director, external research, the Estée Lauder Companies, Melville, N.Y.

“The studies that do exist fall primarily into those that examine the ability of topical antioxidants to control sun-induced DNA damage and immune suppression,” Dr. Matsui says.

According to Dr. Matsui, a review of the literature shows that tea extracts (epigallocatechin gallate, EGCG) have the most data associated with photoprotection. The vitamins C and E in combination and a fern extract (Polypodium sp.) also show promise.

One study using human subjects has been conducted on topically applied tamarind extract.

“Topically applied EGCG, in particular, has been shown to reduce specific UV-induced DNA lesions, to preserve the antigen-presenting cells of the epidermis, the Langerhans cells and to prevent UV-induced immune suppression,” Dr. Matsui says.

CEVAP VER

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