Public release date: 10-Aug-2007

PHILADELPHIA – Concentrated chemicals derived from green tea dramatically boosted production of a group of key detoxification enzymes in people with low levels of these beneficial proteins, according to researchers at Arizona Cancer Center

These findings, published in the August issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, suggest that a green tea concentrate might help some people strengthen their metabolic defense against toxins capable of causing cancer

In a study of 42 people, the concentrate – composed of chemicals known as green tea catechins in amounts equal to that found in 8-16 cups of green tea – boosted production of the enzymes, which belong to the glutathione S-transferase (GST) family, by as much as 80 percent in some participants.

“They actually convert known carcinogens to non-toxic chemicals, and studies have shown a correlation between deficient expression of these enzymes and increased risk of developing some cancers,” Chow said.

“This is the first clinical study to show proof that chemicals in green tea can increase detoxification enzymes in humans,” Chow said. “There may be other mechanism in play by which green tea may protect against cancer development, but this is a good place to start.”