Green tea linked to cancer prevention

Long considered one of the healthiest beverages, green tea may prevent the development of prostate cancer. Moffitt Cancer Center is testing the safety and effectiveness of Polyphenon E, an extract from green tea.

Moffitt is looking for men between 30 and 80 years old who have been diagnosed with prostate cancer within the past three months and have no previous history of cancer or liver disease. The patients must be able to attend monthly sessions for one year.

The study was inspired by population studies that have shown lower occurrences of prostate cancer in Asian men. In a study administered by the California Cancer Registry, Asian men were 34 percent less likely to die of prostate cancer.

“The effect of Polyphenon E has been tested on animals with precancerous cells,” Nagi Kumar, Ph.D., a member of the Green Tea Study team said. “It has shown that if you put green tea in the foods of these animals it prevents the cancer from becoming worse.”

Moffitt is one of the first groups to look into the effects of green tea on prostate cancer. Funded by the National Cancer Institute, the study is now in its second stage. If the results are promising, the study will continue to accommodate more patients.

“Not only are we testing the effectiveness of preventing prostate cancer, we are also looking for any negative side effects that could be caused by taking Polyphenon E,” Dr. Theresa Crocker, a member of the Moffitt team, said.

The investigation is on a national level, with several other research institutes conducting research as well, including the University of Chicago, Jefferson Regional Medical Center in Philadelphia and the James A. Haley Veterans Hospital in Tampa.

More than 30,000 men die of prostate cancer each year. Once diagnosed, most men survive for five years or more but can develop symptoms including impotence, incontinence, osteoporosis and bowel disorders.

Moffitt wants to be sure that the extract is safe to take for a long period of time, Crocker said. But they know that participating in the research won’t necessarily be every man’s cup of tea.

“In this intervention we will be treating participants with the extract Polyphenon E, but they won’t be drinking tea,” she said. If successful, the extract would be given for medicinal purposes.

The study will consist of randomized groups. Some will receive the extract in pill form and others will get a placebo to be sure that any prevention of cancerous cells is the result of the drug and not outside circumstances.

Kumar said there is no conclusive research to suggest that green tea reduces the risk of prostate cancer, but she doesn’t discount the idea. As far as casual green tea drinking, Dr. Kumar recommends the drink.

“We suggest drinking green tea instead of soft drinks, but we don’t know if it will be effective in preventing cancer as of yet,” she said.