Green Tea Detox Cleansing - EGCG Boost Anti-Cancer Enzymes

by Julian
(Horsham)

12 August 2007 - In a study of 42 people, green tea was found to boost the production of detoxifying enzymes, which belong to the glutathione S-transferase (GST) family, by as much as 80 percent in some participants.

GST enzymes are believed to be crucial to the body's defense against cancer-causing chemicals and other toxins, according to the study's lead investigator, H.-H. Sherry Chow, Ph.D., a research associate professor at the University of Arizona.

"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.

"Expression of this enzyme varies dramatically in people due to genetic variation and environmental factors," Chow added. "Green tea catechins somehow increase gene expression of these enzymes, which can be an advantage to people with low levels to start with."

To find out if green tea can protect against cancer, the NCI has sponsored a number of rigorous scientific studies testing capsules of the extract, Polyphenon E, that have been prepared in Japan to meet exact specifications. These pills contain epigallocatechin gallate (EGCG), a catechin known for its potent antioxidant activity, and are currently being tested against a variety of cancers in clinical trials.

This study was designed to see if green tea catechin concentrate had any effect on the levels of GST enzymes in healthy individuals  research that could explain the tea's anti-cancer properties. Volunteers were asked to take four Polyphenon E capsules, for a total of 800 milligrams of EGCG, each morning on an empty stomach for four weeks.

Researchers found that use of Polyphenon E enhanced GST activity. But it had its most significant effect in volunteers whose baseline blood measurements showed low GST activity -- an 80 percent increase compared to baseline GST activity. Activity did not change in volunteers with medium GST expression, or in those with the highest levels, GST seemed to decrease slightly although researchers believe that decline was due to random variation.

"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."

American Association for Cancer Research (2007, August 12). Green Tea Boosts Production Of Detox Enzymes, Rendering Cancerous Chemicals Harmless. ScienceDaily. Retrieved August 12, 2008, from http://www.sciencedaily.com­ /releases/2007/08/070810194923.htm