Green tea’s ability to fight cancer is even more potent and varied than scientists suspected, say researchers who have discovered that chemicals in green tea shut down one of the key molecules that tobacco relies upon to cause cancer. It’s a find that could help explain why people who drink green tea are less likely to develop cancer.

Christine Palermo and Thomas Gasiewicz, PhD, set out to measure the effects of the chemicals found in green tea on a molecule known as the aryl hydrocarbon (AH) receptor, a molecule that is particularly susceptible to toxic substances like tobacco smoke and dioxin. The team isolated the chemicals that make up green tea and found two that inhibit AH activity. The two substances, epigallocatechingallate (EGCG) and epigallocatechin (EGC), are close molecular cousins to other flavonoids found in broccoli, cabbage, grapes and red wine that are known to help prevent cancer.

“Right now we don’t know if drinking the amount of green tea that a person normally drinks would make a difference, but the work is giving us insight into how the proteins work,” says Palermo, who enjoys cold green tea herself. “There are a lot of differences between various kinds of green tea, so a lot more research is needed.”

University of Rochester Medical Center, Aug 4, 2003