Prostate cancer is one of the most common types of cancer found in American men and it is estimated that 1 man in 6 will get prostate cancer during his lifetime.
A new study investigated the effects of a botanical antioxidant in subjects with prostate cancer. The botanical antioxidant? Green tea extract.
In this new study, 26 men with confirmed prostate cancer were given a supplement of green tea constituents. The supplement contained a total of 1.3 grams of green tea polyphenols, which included 800 mg of epigallocatechin-3-gallate ( EGCG ) and lesser amounts of epicatechin, epigallocatechin, and epicatechin-3-gallate.
The men received the green tea supplement until the time of their radical prostatectomy surgery, averaging a supplementation period of 34.5 days.
Blood tests were performed at the beginning of the study and again on the day of surgery. The blood tests included:
prostate-specific antigen (PSA), a test commonly performed to monitor prostate health
hepatocyte growth factor (HGF) which is a factor that regulates cell and tumor growth
vascular endothelial growth factor (VEGF) which is a signaling protein believed to influence cancer progression
insulin-like growth factor (IGF)-I which is a protein that has been shown to play a role in the development of cancers
IGF binding protein-3 which regulates the activity of IGF
liver function tests to monitor possible toxicity.
In addition, cancer-associated cells known as fibroblasts were treated in vitro with EGCG and were tested for HGF and VEGF.
The study showed a significant reduction in the levels of the serum cancer biomarkers HGF, VEGF, PSA, and liver enzymes in the test subjects after treatment with the green tea supplement. Additionally, some patients demonstrated reductions in levels of these biomarkers greater than 30 percent. The in vitro study of the fibroblasts showed a decrease in the production of HGF and VEGF as well.
The researchers concluded that the findings support a potential role for green tea "in the treatment or prevention of prostate cancer."
McLarty J, Bigelow RL, Smith M, Elmajian D, Ankem M, Cardelli JA. Tea Polyphenols Decrease Serum Levels of Prostate-Specific Antigen, Hepatocyte Growth Factor, and Vascular Endothelial Growth Factor in Prostate Cancer Patients and Inhibit Production of Hepatocyte Growth Factor and Vascular Endothelial Growth Factor In vitro. Cancer Prev Res (Phila Pa). 2009 Jun 19. Published Online Ahead of Print.