> Unleashing an ancient remedy for the future of skin protection
Beyond cosmetic damages, such as wrinkles and age spots, exposure to the sun’s ultraviolet light is the environmental culprit repeatedly blamed for the most common form of cancer—skin cancer, which the American Cancer Society estimates accounts for half of all cancers in the United States. Finding innovative techniques to guard skin against ultraviolet light damage is a focal point and driving motivation of physician-researchers at Case Western Reserve University School of Medicine and University Hospitals Case Medical Center, who have zeroed in on what may seem to be an unexpected interest: the teakettle.
Green tea has grabbed headlines for years for its antioxidant properties, which have been credited for its ability to lessen the risk of developing cancers of the breast, stomach, esophagus, prostate and pancreas. Green tea and its less-known cousin, white tea, have long been hailed by the Chinese for their medicinal benefits and more recently have been marketed as cures for everything from bad breath to arthritis.
Tea is abundant in unique catechin polyphenols, especially epigallocatechin gallate, or EGCG—a chemical substance often cited as giving tea its healthy punch and the compound that makes it an attractive target for research.
“Tea’s benefits have been known for many ages, but they’ve never been well studied in a controlled, randomized trial,” says Elma Baron, MD, associate professor of dermatology at the School of Medicine and director of the Skin Study Center, a core facility of the NIH-funded Skin Disease Research Center and a joint center of the School of Medicine and University Hospitals Case Medical Center. “Ours is the first study to examine the role of white tea on sun protection.”
Dr. Baron, the lead investigator of the study, explains that antioxidants play a major role in the prevention of damage caused by sunlight. Ultraviolet light emitted by the sun causes oxidative stress on the skin cells, which has been implicated as the cause of many diseases, including cancer. Antioxidants, which are plentiful in teas, citrus fruits and tomatoes, for instance, have the potential to counteract this process. Therefore, Dr. Baron theorizes, “If you look at botanical agents, like tea, that have the potential to counteract oxidative stress, you will find something that will be good for the skin.”
The stage was set for a multi-faceted, multi-year collaboration between experts in the Department of Dermatology and the Estée Lauder Companies that examined two topical formulations—one with green tea and another with white—to determine if either could prevent the cellular damages caused by exposure to ultraviolet light.
“Tea in general has antioxidant properties, whether it’s black, green or white,” Dr. Baron says. “There have been studies that have demonstrated the benefits of drinking tea, and by doing so, you might derive benefits in other organ systems. For tea to make a difference in your skin’s ability to withstand ultraviolet light damage, however, some studies have shown you would have to drink nearly eight glasses a day. That’s why we’re looking toward topical application instead of oral ingestion.”
In the study, conducted from the Skin Disease Research Center and published in Experimental Dermatology, green and white tea lotions were applied to a group of healthy volunteers prior to, and immediately following, exposure to simulated radiation that mimicked a typical midsummer afternoon. Then, a biopsy was taken of all exposed areas.
“We found that the application of each green and white tea prevented the formation of 8-hydroxyguanine, a marker of oxidative damage to the DNA ,” says Kevin D. Cooper, MD, professor of dermatology, chair of the Department of Dermatology and co-investigator of the study. “Both the green tea and the white tea were effective in reducing the evidence of sun damage to the skin.”
The next generation
Dr. Cooper says this research revealed that tea extracts offer a deeper level of protection than simply shielding the skin from sunburn. “Sun protection factor—SPF—is a misnomer because it’s really only a redness-protection factor,” Dr. Cooper says. “We need to test for the bigger picture of damage to the skin.”
Mary S. Matsui, PhD, is executive director of external research for the Estée Lauder Companies, which has partnered with the experts in skin biology and immunology at the School of Medicine since the mid-1990s. She says the organizations are collaborating on a three-year study to scrutinize the molecular changes that occur when skin sees the sunlight—going far beyond the visible redness.
“This way, we can better track the progress and the efficacy of products to counteract the negative effects of sunlight,” she says. “It’s a very big project and we’re really digging deeper.”
In the meantime, however, tea polyphenols are being considered among the compounds that can complement already well-known sun protection strategies, such as sunscreens.
“We did not test a final product that I can tell people, ‘Go to your local drugstore and grab that one,’” Dr. Baron says, “but hopefully it will streamline our efforts and develop sun protection options that would truly be of help to consumers.”