HOUSTONThe first clinical study in the United States of green tea as an anticancer agent is underway at The University of Texas M.D. Anderson Cancer Center and Memorial Sloan-Kettering Cancer Center. If this trial and future studies show a benefit, the next step would be to get Americans to switch from their usual black tea to the Asian green variety, which has a milder flavor.
The phase I study will determine the amount of the tea a cancer patient can take before experiencing the side effects of caffeine such as heartburn or difficulty sleeping.
Katherine Pisters, MD, the principal investigator of the study and assistant professor of medicine at M.D. Anderson, said that M.D. Anderson has obtained an IND (investigational new drug) permit from the FDA to begin the research.
Research in Japan has shown that individuals who drink green tea have a lower incidence of cancer and that Japanese who drink green tea and are diagnosed with cancer generally are diagnosed at an older age. In addition, laboratory studies have shown that green tea inhibits tumor growth and metastases in animals.
The researchers plan to enroll up to 30 patients with advanced solid tumors. The study subjects will take daily capsules of formulated powdered green tea for up to six months, or possibly longer if the treatment appears beneficial. The powder will be the equivalent of up to 10 cups of green tea a day. The study should be completed in less than two years.
We are studying a plant that has been used as a beverage in Asia for hundreds of years, Dr. Pisters said. 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. She added that since 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 effects of the extract, it is important to conduct the research with individuals who do not already drink green tea on a regular basis, she said. 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.
The phase I trial is being supported by the ITO-EN Central Research Institute in Shizuoka, Japan, which was founded by the ITO-EN Company, the largest manufacturer and distributor of green tea in Japan.