April 20, 2004 -- Green tea, black tea, seems it doesn't matter. Drinking tea may slow prostate cancer growth, a new study shows.
The newest findings on prostate cancer were presented at the annual Experimental Biology 2004 meeting held this week in Washington.
For their study, researchers recruited 20 men being treated for prostate cancer. They were randomly assigned to drink five cups of green tea, black tea, or soda each day before surgery to remove the tumor and prostate. Their blood was analyzed before the study for levels of phenols -- an antioxidant that may have antitumor effects.
After their surgery, the men's blood was analyzed again -- as was their prostate tissue.
While phenols were also found in the men's blood samples, there were no significant differences between the groups, reports researcher Susanne Henning, PhD, with the Center for Human Nutrition at UCLA.
However, the men's prostate tissue samples revealed a different story:
- Those drinking the most tea had the most tea phenols in their prostate tissue samples.
- They also had lower levels of polyamines, a chemical associated with malignancy (cancer cells).
In a laboratory experiment, Henning looked at cancer cell growth when the men's tissue samples were exposed to black tea, green tea, or soda in a petri dish. Cancer cell growth was significantly slower with both black and green tea, reports Henning.
Henning plans more studies of green tea extract in supplement capsule form, to see if it can help prevent prostate cancer.