Green Tea Extract May Inhibit Tumor Growth

Over the past decade, green tea and green tea extract have been the subject of a significant amount of research. Studies have linked the polyphenols in green tea to a myriad of potential benefits, including possible cancer benefits, heart benefits, and even reduced risk of "all-cause mortality."¹

Now, a new study at Rutgers University has found that the green tea compound Epigallocatechin-3-gallate (EGCG) may inhibit human lung cancer tumor growth.² Previous studies have found that EGCG may inhibit tumor growth in animal models, but this is the first study to demonstrate the dose-dependent response in lung cancer. For the study, the researchers tested the response of human lung cancer H1299 cells in culture and in xenograft tumors in rats (human lung cancer tumors were grafted onto the lungs of lab rats).

Tumor growth was inhibited in the by EGCG at doses of 0.1 percent, 0.3 percent and 0.5 percent in the diet. The tumor inhibition was caused by tumor cell apoptosis and oxidative DNA damage, which were dose-dependently increased by EGCG treatment. While EGCG is classified as an antioxidant, it seems to have a pro-oxidant effect on the tumor cell's DNA.

The cultured tissue was used to estimate the IC50 (half maximal inhibitory concentration) that the EGCG levels would need to reach to inhibit cell growth in the xenogaft tumors. It was estimated that the IC50 would be 20 microMols; however, the IC50 turned out to be much lower, at just 0.15 microMols. This level means that the use of EGCG as an adjunct therapy may be possible through oral supplementation.

EGCG is the primary polyphenol in green tea. Previous studies have tied it to a wide range of potential health benefits ranging from weight loss and improved metabolic health to improved prostate health to improved oral health.

Learn more about the potential benefits of Green Tea Extract here.

1. Kuriyama, S., T. Shimazu, et al. (2006). "Green tea consumption and mortality due to cardiovascular disease, cancer, and all causes in Japan: the Ohsaki study." Jama 296(10): 1255-65.

2. Li, G. X., Y. K. Chen, et al. "Pro-oxidative Activities and Dose-response Relationship of (-)-Epigallocatechin-3-gallate in the Inhibition of Lung Cancer Cell Growth: A Comparative Study in vivo and in vitro." Carcinogenesis.