The study involved 26 prostate cancer patients ages 41 to 68, who were given green tea extract capsules. These capsules were made from the polyphenols in green tea and are named Polyphenon E. The tablets are manufactured by Polyphenon Pharma and contain epigallocatechin gallate or EGCG.

In the current study, participants were asked to consume four Polyphenon E capsules a day. This routine for followed for 30 days prior to their prostate surgery.

The researchers reported that after one month the levels of three proteins considered important for the spread of the cancer were reduced in the blood
* Hepatocyte growth factor or HGF was reduced by 18.9%
* Vascular endothelial growth factor or VEGF fell by 9.9%
* Prostate specific antigen PSA fell by 10.4%

Lead researcher Dr James Cardelli, from the Feist-Weiller Cancer Center said the study was evidence that some cancers can be prevented and that such options need to be further explored, "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.

The details of the study are reported in the July issue of Cancer Prevention Research.

Polyphenols are thought to be important nutrients for human health especially in combating oxidative stress, which is a leading cause of various diseases. Dietary sources of polyphenols include apples, blackberries, blueberries, cantaloupe, cherries, cranberries, grapes, pears, plums, raspberries, strawberries, broccoli, cabbage, celery, onion, parsley, chocolate and green tea.

Green tea has proved useful in preventing heart disease, cancer and Alzheimer's disease in previous studies. This study further reinforces its utility in cancer-prevention.