Oct. 29, 2003 -- A mélange of pomegranates, grapes, and citrus fruits may sound like an exotic fruit salad, but new research shows it may also be a powerful new weapon against skin cancer.
Researchers say the incidence of skin cancer is rising faster than any other type of solid tumor in the U.S. and new approaches in preventing and treating skin cancers are needed to prevent an epidemic of skin cancer. Skin cancer is already the most common type of cancer in the U.S., and more than 1.3 million cases are diagnosed each year.
If further studies confirm these results, researchers say skin cancer-fighting creams and sunscreens containing extracts of pomegranates, grapes, and citrus fruits may be coming to a cosmetics counter or pharmacy near you soon.
Fruit Extracts Fight Sun Damage
The studies, presented in Phoenix today at the American Association for Cancer Research's second annual International Conference on Frontiers in Cancer Prevention Research, looked at the effects of three different fruit extracts in preventing sun-related skin damage in animal and laboratory tests.
In the first study, researchers applied pomegranate fruit extract to the skin of laboratory mice 30 minutes before they were exposed to chemically induced skin cancer and compared the results to mice that received only the chemical that causes skin cancer.
Researchers say the pigment that gives pomegranates and other fruit their dark red color have higher levels of antioxidant activity than both red wine and green tea, and even small amounts of pomegranate extract was enough to produce significant results.
The study showed that only 30% of the animals treated with the extract developed skin cancer after 16 weeks compared with 100% of the nontreated mice. Those animals that did develop skin cancer despite the extract treatment had on average smaller tumors than those animals not receiving the pomegranate extract treatment.
In the second study, researchers looked at the effects of applying resveratrol, an antioxidant found in the skins of grapes and in red wine, to hairless mice who were then exposed to skin cancer-causing ultraviolet (UVB) rays.
They found that resveratrol significantly inhibited UVB-related skin damage that commonly precedes skin cancer.
In the third study, researchers tested the effects of perillyl alcohol, a compound found in citrus fruits, mint, and tart cherries, on human skin cells that were treated with the compound and then exposed to UVB rays. Again, the fruit extract inhibited cellular changes in the skin cells that commonly occur after UVB exposure.
Fruity Ways to Prevent Skin Cancer
"The real impact of these papers is that in each case there is an attempt to really evaluate the mechanistic effects of these food ingredients and take the voodoo and mysticism out of nutrients, which in this area of skin cancer prevention is very important," says David Alberts, MD, of the University of Arizona, who moderated a discussion of these studies at a briefing today.
"Ultimately, if we can identify what the targets are and where these agents are inhibiting, I think it adds fuel to interest in this area," says Alberts.
Researchers say if further research confirms these preliminary findings, skin care products such as creams, patches, and sunscreens containing these elements may be developed to protect the skin against cancer.
Though eating fruits or drinking beverages containing these compounds may also offer some skin cancer protection, researchers say the amount of the cancer-fighting elements that reaches the skin is not nearly as significant as when the extracts are applied directly to the skin.