Green Tea Extract Slows Prostate Cancer
Extracts in green tea are shown to slow the progression of prostate cancer according to a new study from researchers in the Feist-Weiller Cancer Center, LSU Health Sciences Center-Shreveport. The study is the second phase of a clinical trial using the investigational agent Polyphenon E, an extract from green tea. Polyphenols are active ingredients found in green tea, previously implicated for their positive effect on prostate cancer, but studies have been contradictory.
The researchers conducted the impact of short-term use of the active compounds in green tea on men with prostate cancer. The scientists monitored blood tests that show progression of prostate cancer in 26 men, aged 41 to 72 years, diagnosed with prostate cancer and scheduled for removal of the prostate gland.
The men took four capsules containing Polyphenon E until the day before prostate surgery, equal to about 12 cups of concentrated green tea. The average study time was just over one month (34.5 days). The researchers found significant slowing of prostate cancer. In some of the men, prostate cancer growth slowed by thirty percent, with minimal side effects.
Recent studies show that men with abnormal prostate cells, high-grade prostate intraepithelial neoplasia (HGPIN), also benefited from polyphenols extracted from green tea. James A. Cardelli, Ph.D., professor and director of basic and translational research at the LSU health sciences center say, "These studies are just the beginning and a lot of work remains to be done, however, we think that the use of tea polyphenols alone or in combination with other compounds currently used for cancer therapy should be explored as an approach to prevent cancer progression and recurrence." Polyphenols may benefit other forms of cancers, as well as slowing the progression of prostate cancer.
The study is not conclusive. More research needs to be done with better controls to be certain there were no other factors besides green tea extract responsible for slowing the progression of prostate cancer in the men studied. The study supports the notion that beneficial compounds found in plants and derived from a healthy diet can help prevent and slow cancer. The researchers are planning more studies to find out why prostate cancer progression was affected more in some men than others who were given Polyphenon E, a drug produced from green tea extracts.
American Association for Cancer Research