Previous studies have suggested that this antioxidant may protect against
breast cancer and other cancers, but this research has been limited, and the
mechanism behind these effects isn't clear.
Researchers say the results suggest that green tea's anticancer effects may
be largely because of its high content of EGCG, which helps the body's cells
from becoming damaged and aging prematurely.
Behind Green Tea's Anticancer Effect
In the study, presented this week at the Experimental Biology 2008
conference, researchers examined the effects of the green tea antioxidant on
several indicators of breast cancer growth in laboratory mice.
One group of the female mice was fed a solution of the antioxidant in water
for five weeks while the other received regular drinking water. During the
second week of the study, researchers injected both groups with breast cancer
At the end of the study, researchers measured tumor size, weight, and
density as well as VEGF protein levels associated with tumor growth.
The results showed that treatment with the green tea antioxidant decreased
tumor size by 66% and weight by 68% compared with the control group. Mice fed
the antioxidant also had significantly lower density of small blood vessels
within tumors and VEGF protein levels.
Researcher Jian-Wei Gu, of the University of Mississippi Medical Center in
Jackson, says the green tea antioxidant may work against breast cancer by
suppressing blood vessel growth in breast tumors as well as slowing the
proliferation and migration of breast cancer cells.
Gu, J. "Oral Administration of EGCG, an Antioxidant Found in Green Tea,
Inhibits Tumor Angiogenesis and Growth of Breast Cancer in Female Mice,"
presented at Experimental Biology 2008, April 6-9, 2008, San Diego.
News release, The American Physiological Society.