In the first study of its kind to determine the absorption and antitumor effects of tea polyphenols in human tissue, researchers from the University of California, Los Angeles found tea polyphenols in prostate tissue when subjects consumed tea for only a short amount of time. Polyphenols are the compounds in tea that have been found to be responsible for the many health benefits of the drink. The findings were reported at the Experimental Biology 2004 meeting held in April in Washington, DC.
Twenty prostate cancer patients scheduled for radical prostatectomy were administered five cups of green tea, five cups of black tea, or soda containing no polyphenols for five days. Blood was collected before and after the treatment period and serum added to prostate cancer cell line samples. Following the surgeries, polyphenols were detected in all of the prostates excised from men who received black tea, six out of eight of the prostates taken from men who received green tea, and in two out of five of those who received soda (which may have been because they were consuming chocolate or tea before the study). Serum obtained from participants after five days of drinking tea was associated with slower growth when added to the prostate cancer cell cultures compared to serum obtained before the treatment period. No reduction in cancer cell growth was observed when serum from men who drank soda for five days was administered to prostate cells.
Additionally, levels of polyamines, which have been associated with malignancy in humans, were found to be negatively correlated in the prostate with the presence of tea polyphenols .
"This is the first human study to show that EGCG (epigallocatechin gallate, a polyphenol in the tea) shows up in the prostate after drinking tea," says Dr. Henning, "This strengthens the idea that green tea and black tea help prevent prostate cancer."
Lead author Dr Susanne Henning, of the UCLA Center for Human Nutrition, believes that these findings suggest that black and green tea are promising dietary supplements for the prevention of prostate cancer.
Susanne Henning, Ph.D., R.D., associate researcher, Center for Human Nutrition, UCLA David Geffen School of Medicine, Los Angeles; Herman Kattlove, M.D., spokesman, American Cancer Society; Thomas Walle, Ph.D., professor, pharmacology, Medical University of South Carolina, Charleston; April 18, 2004, presentations, Experimental Biology 2004, Washington, D.C.