Researchers Studying Effects of Green Tea on Cancer Patients

Researchers at The M.D. Anderson Cancer Center and Memorial Sloan-Kettering are embarking on a study that may evolve into a series of studies examining the potential benefits of green tea for treating and preventing cancer. The protocol is the first ever in the United States to be conducted with green tea.

The phase I clinical study will determine the amount of the tea a cancer patient can take before experiencing the side effects of caffeine.

Research in Japan has shown that individuals there who drink green tea—which has a milder flavor than the black tea that Americans generally prefer—have a lower incidence of cancer. Studies also have shown that Japanese who drink green tea and who are diagnosed with cancer generally are diagnosed at an older age.

Additionally, laboratory studies have shown that green tea inhibits tumor growth and metastases in animals, paving the way for similar studies in cancer patients.

“We are very excited to have this opportunity to perform the first clinical study of green tea in the United States,” says Dr. Waun Ki Hong, chairman of the Department of Thoracic/Head and Neck Medical Oncology at M.D. Anderson.

“There is tremendous interest right now in using natural substances to treat and prevent disease. Green tea has been shown to inhibit many kinds of cancer in laboratory and population-based studies in Japan, and since it appears to have very few side effects. it has tremendous potential for widespread use,” Dr. Hong continued.

Dr. Katherine Pisters, the principal investigator of the study and assistant professor of medicine at M.D. Anderson, pointed out that M.D. Anderson has obtained an investigational new drug permit from the Food and Drug Administration to begin the research.

Study to Be Completed in Under 2 Years

As many as 30 cancer patients with advanced solid tumors will participate in the study, and they will take daily capsules of formulated powdered green tea for up to 6 months—or possibly longer if the treatment appears to be beneficial. The study, which will be conducted both at M. D. Anderson and Memorial Sloan-Kettering Cancer Center in New York, should be completed in less than 2 years, reports Dr. Pisters.

Dr. Pisters explained that the “dose-escalation” study will examine the safety of taking the equivalent of up to 10 cups of green tea a day.

“We are studying a plant which has been used as a beverage in Asia for hundreds of years. If green tea proves to be safe, which seems likely, we can expand our studies to phase II and phase III trials to test its effectiveness in preventing and treating various types of cancer,” Dr. Pisters said.

Because green tea is not the tea generally preferred by Americans, the United States is fertile ground for conducting such a study. “In order to precisely determine the effect of the extract, it is important to conduct the research with individuals who do not already drink green tea on a regular basis. In the United States, green tea is currently almost unknown. However, I believe it will become more popular as people become aware of its possible health benefits,” Dr. Pisters added.