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Title: Purified Green Tea Polyphenol Capsules Taken Daily Appear to Substantially Reduce Prostate Cancer in High Risk Patients: Presented at AACR

"Purified Green Tea Polyphenol Capsules Taken Daily Appear to Substantially Reduce Prostate Cancer in High Risk Patients: Presented at AACR"

By Ed Susman ANAHEIM, CA -- April 22, 2005 -- A preparation of polyphenols that are extracted from green tea appear to prevent progression to prostate cancer in men at high risk of the disease. In the small, double-blind, placebo-controlled trial, researchers reported a 90% decrease in the rate of prostate cancer in men who received 200 mg doses of the polyphenol capsules three times a day for 1 year. "We were hoping that maybe we could have a 50% reduction. So we were very surprised by these results," said Saverio Bettuzzi, PhD, associate professor of biochemistry, University of Parma, Italy, at the 96[^th annual meeting of the American Association for Cancer Research.

The men in the trial were all diagnosed with high grade prostatic intraepithelial neoplasia (PIN). In the natural history of high grade PIN, about 30% of patients are expected to progress to cancer within a year -- exactly the percentage than progressed in the placebo group of Dr. Bettuzzi's trial (9 men out of 30), the researcher said.

Of the 32 patients assigned to receive caplets of green tea catechins, only one progressed to cancer -- a 3% rate. "That represents a highly significant 90% reduction in the risk of developing prostate cancer," he said here on April 20^th.

"This is a tantalizing result and study," said William Nelson, MD, professor of oncology, urology, pharmacology and molecular science, medicine, pathology and radiation oncology at the Johns Hopkins University School of Medicine. "However, I think a large study is necessary to confirm the results of this trial before we all start taking these polyphenols. We also need to see what happens after a year. We need to know if the green tea extracts healed the PIN lesions or just delayed their progression."

Dr. Bettuzzi said that the patients in the trial would be followed for 5 more years. He is also trying to find partners interested in developing a larger trial with at least 300 men in each arm.

Dr. Bettuzzi said that the amount of green tea extract in the caplets would amount to drinking about 15 to 20 cups of the tea a day -- which could be associated with adverse effects such as insomnia due to high caffeine intake. He said the caplets used in the study were decaffeinated.

The researchers from the University of Parma and the University of Modena recruited men undergoing biopsy for a suspicious prostate gland. In most cases the men had a benign enlargement of the gland, but in other cases the biopsy showed PIN.

The men who volunteered were between the ages of 45 to 75 and were randomized to take the daily caplets of catechins or placebo. They underwent biopsy at 6 months and at a year.

Dr. Bettuzzi and colleagues said that in addition to reduced cancer risk, patients taking the green tea extract also showed some shrinkage of their prostate glands.

Previous studies have shown that green tea catechins and other polyphenols appeared to inhibit cancer cell lines, and epidemiologic studies have indicated lower prostate cancer rates in patients who consume high levels of dietary polyphenols.

[Presentation title: Chemoprevention of Human Prostate Cancer by Oral Administration of Green Tea Catechins in High Grade PIN Subjects: a Preliminary Report From a 1 Year Proof of Principle Study. Abstract 4400]

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