• 10/8/2004
  • Medical College of Georgia
  • Medical News Today (online)

The health benefits of green tea are finding their way into gum, mints, skin cream and other products with the help of a Medical College of Georgia cell biologist. Dr. Stephen Hsu, a researcher in the MCG Schools of Dentistry and Graduate Studies whose work has revolutionized the understanding of green tea’s healing and preventive properties, recently began an arrangement with New Jersey-based CCA Industries, Inc. to make those properties readily available in everyday products. The first of these products, Mega-T Green Tea Chewing Gum, is on store shelves now. Each piece of the mint-flavored, sugar-free gum equals two cups of green tea.

Dr. Hsu has been intrigued by the properties of green tea since observing that populations that drink green tea regularly have much lower cancer rates than populations that don’t. His research helped determine that green tea polyphenols help eliminate free radicals, which can damage DNA and lead to cancer. He further found that green tea-induced p57–a protein that helps regulate cell growth and differentiation–changes the behavior of healthy cells as polyphenols target cancer cells for destruction. This change of behavior protects the healthy cells.

Dr. Hsu discovered that the polyphenols activate two separate pathways, one for normal cells and one for cancer cells. The polyphenols serve as a sentinel, separating cells with p57 from cancer cells, which lack p57. He found that while the normal cells are shuttled to safety, the polyphenols destroy the mitochondria of cancer cells.

A National Cancer Institute grant is helping him determine the exact genetic behavior involved in this process. For instance, he has already found that a green tea polyphenol called EGCG increases reactive oxygen species, or ROS, a form of oxidative stress in oral cancer cells. “Cells with abnormally high levels of ROS become damaged,” he said. “If the level is very high, the cells will be killed. On the other hand, ROS is brought to background levels by EGCG in normal skin and salivary gland cells, suggesting a protective role of EGCG in normal cells.”

Some methods of bolstering ROS are inadvertent; for instance, excessive sun exposure can increase ROS to the point of irreversible cell damage. Chronic exposure to carcinogens and certain drugs also can damage salivary gland cells.

Dr. Hsu and his colleagues found that when they added EGCG to cells, the polyphenols increased ROS levels in cancer cells but reduced them in healthy salivary gland and skin cells.

“All of our data indicate that EGCG can lower the ROS level [of healthy cells] and keep it low,” Dr. Hsu said. “This is very exciting because perhaps we can use EGCG to protect healthy cells and prevent side effects from medications that impair salivary function and cause dry mouth.”

For instance, oral cancer treatment can severely damage the salivary gland. “When this happens, the patient can no longer effectively secrete saliva and has a chronically dry mouth,” Dr. Hsu said.

Dry mouth also affects some people without cancer, including fully 30 percent of the elderly, Dr. Hsu noted. The green tea gum not only protects the tissue but stimulates the salivary glands to produce more moisture.

Healthy people can chew the gum for preventive health, or just to enjoy a piece of gum, Dr. Hsu said, noting that the cost is comparable to that of regular gum. He suggests chewing a piece at least 15 minutes for optimal health benefits.

Mints and skin-care products will be on store shelves soon, he said, noting that fitness leader Denise Austin is creating a signature brand of green-tea skin care products and cosmetics for CCA Industries.