The polyphenols present in green tea help prevent the spread of prostate cancer by targeting molecular pathways that shut down the proliferation and spread of tumor cells, as well as inhibiting the growth of tumor nurturing blood vessels, according to research published in the December 1 issue of Cancer Research.

A team of researchers from the University of Wisconsin, Madison, Wis., and Case Western Reserve University, Cleveland, Ohio, documented the role of green tea polyphenols (GTP) in modulating the insulin-like growth factor-1 (IGF-1)-driven molecular pathway in prostate tumor cells in a mouse model for human prostate cancer. "Consumption of GTP led to reduced levels of IGF-1," said Hasan Mukhtar, Ph.D., Department of Dermatology at the University of Wisconsin, the senior author of the paper.

"Consumption of GTP led to reduced levels of IGF-1," said Hasan Mukhtar, Ph.D., Department of Dermatology at the University of Wisconsin, the senior author of the paper. "GTP also led to increased levels of one of the binding proteins for IGF-1, the insulin growth factor binding protein-3. These observations bear significance in light of studies that indicate increased levels of IGF-1 are associated with increased risk of several cancers, such as prostate, breast, lung and colon."

The green tea polyphenols contributed to minimizing tumor development by governing the amount of vascular endothelial growth factor (VEGF) in the serum of the prostate cancer mouse model. The reduction of VEGF may result from GTP-induced suppression of IGF-1 levels. VEGF functions to recruit and develop new blood vessels that carry nutrients to developing tumors. By reducing the amount of VEGF, GTP works to minimize nutrients flowing to and supporting tumor growth.