Green Tea Slows The Progression Of Prostate Cancer

By Margarita Nahapetyan

Green tea appears to slow the progression of prostate cancer, researchers reported on Friday. Men with the disease who consumed the active compounds found in green tea, showed lower levels of protein that tumors use to grow, a U.S. study found.

The difference between green tea and the black tea is in that green tea is not fermented before drying. This fermentation process appears to decrease the content of flavonoids - which have beneficial antioxidant properties, believed to protect against cell damage - by up to 90 per cent.

Previous studies have demonstrated that green tea may have a positive effect on a large number of serious conditions, such as heart disease, cancer and Alzheimer's disease. Green tea is also beneficial for the arteries, it brings down the levels of 'bad' cholesterol and blood pressure, and reduces harmful liver enzymes as well.

Drinking green tea could help slow down the process off cancer, with some studies finding that with only 4 cups of green tea per day, cell damage in heavy smokers, that might result in the development of tumors, can be prevented. For the new study purposes, the investigators from Philadelphia have analyzed a compound called Polyphenon E. They were testing a number of biomarkers - molecules - such as vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) which are the indicators of developing cancer. Researchers also looked for prostate specific antigen (PSA) - a a protein marker used to chart progress of the disease and which can only be found in the prostate. In case of cancer, the levels of PSA can be increased.

The study involved 26 men, with the ages between 41 and 72 years, who had been diagnosed with prostate cancer. All patients were scheduled to undergo radical prostate surgery. The participants were asked to take 4 capsules containing Polyphenon E for an average of 34 days, up before the day of operation. Four capsules were the equivalent of approximately 12 cups of normally brewed concentrated green tea.

The results revealed that there was a noticeable drop in scores of PSA and two other biomarkers in the majority of patients. Some patients showed reductions of more than 30 per cent. There were few reported side effects, and the men's liver function remained within a normal range, according to Dr. James A. Cardelli, a professor and director of basic and translational research at the Feist-Weiller Cancer Center at Louisiana State University Health Sciences Center-Shreveport, and his fellow colleagues. The present study follows a year-long trial in Italy which also found that drinking green tea cut the risk in men with pre-cancerous signs of prostate.

Dr. Cardelli said: "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." He added that there is good evidence that many types of cancers can be prevented, and that their studies using herbal substances add to the idea that plant compounds found in a healthy diet can play a significant role in preventing development and progression of the disease.

Prostate cancer is the second leading cause of cancer death among men in the United States. The American Cancer Society projects that the condition will be diagnosed in 192,280 men and will kill 27,360 in 2009. The current study that included just 26 prostate cancer patients was a small trial and the scientists say that further investigation involving a larger number of patients would be needed in order to support the results.

The study is published in the Cancer Prevention Research journal.