For the tea study, Susanne Henning, an associate researcher at the Center for Human Nutrition at UCLA's David Geffen School of Medicine, assigned 20 men, all scheduled for prostate removal due to cancer, to drink either black tea, green tea or soda, five cups a day for five days before surgery.
The aim was to see if substances called polyphenols found in tea might slow prostate cancer cell growth. Other researchers have found these polyphenols induce death in cancer cells. Green and black tea can slow down the spread of prostate cancer, while a highly touted antioxidant found in red wine, grapes and peanuts does not perform well as a cancer preventive, two new studies have found, report yahoo.com
According to telegraph.co.uk recent animal and epidemiological studies have suggested that tea may have anti-tumour effects and, in studies of tea-drinking rats and mice, the polyphenolic components of tea were found in the prostate and other tissues.
They found that prostate cancer cells grew more slowly when exposed to the blood serum of men who had consumed either green or black tea for five days compared with serum collected before the men began their tea-drinking regimen.
Serum from a control group of men who drank comparable amounts of carbonated drink showed no such slowing in cancer cell proliferation. Analysis of the prostate tissue showed a large variation in tea polyphenol content between study participants.
Tea polyphenols were found in six out of eight participants drinking green tea, seven out of seven drinking black tea, and two out of five drinking soda. The fact that two of the control participants showed polyphenols in the prostate sample might be because they were eating chocolate regularly or drinking tea before entering the study.
Chocolate does contain the polyphenols epicatechin and epicatechingallate, and the turnover rate of these polyphenols - how long they might remain in tissue - is not known. They are water-soluble and are all excreted after eight hours. The maximum concentration in plasma is after two to three hours.
Prostate cancer is one of the common cancers among males in the United States, and more than a fourth of all those patients with prostate cancer are known to use alternative therapies, including green tea. This study suggests that both black and green tea are promising natural dietary supplements useful for chemoprevention of prostate cancer, according to Dr. Henning. She plans to investigate if this effect can be enhanced by consuming larger amounts of tea polyphenols in the form of green tea extract supplement capsules, inform eurekalert.org