PREVENTION AGENTS

Tea Polyphenols

What are they?

Tea polyphenols are compounds in tea leaves that are natural plant antioxidants. Antioxidants have been shown to prevent damage caused by free radicals to DNA and other molecules.

How do they work?

Tea polyphenols have demonstrated several cancer preventive properties. In addition to antioxidant activity, these compounds may reduce abnormal cell growth and inflammation; help the body get rid of cancer-causing agents; and restore communication between different cells in the body.

What do the data show?

The relationship between tea consumption and human cancer has been studied in several different populations and at various cancer sites. Some of the studies comparing tea drinkers to non-tea drinkers support the claim that tea-drinking prevents cancer, others do not. Dietary, environmental, and population differences may account for these inconsistencies. In animal studies, different tea extracts, tea polyphenol mixtures, purified tea components, and tea infusions as the sole drinking fluid have more consistently been shown to prevent cancer, including cancers of the colon, esophagus, liver, stomach, lung, breast, pancreas, and skin. The purified component, epigallocatechin gallate (EGCG), prevented colon cancer, but did not prevent cancer of the esophagus in animal models. A polyphenol mixture with EGCG, called Polyphenon E, has also shown cancer preventive properties in animals. Animal studies were inconclusive as to whether EGCG or Polyphenol E caused DNA mutations that might trigger cancer growth. Both EGCG and Polyphenon E are being tested for safety and efficacy in humans.

Complementary Names

Chemical name:	Various
Also known as:	Green Tea Polyphenols, Green Tea Water Extract, Black Tea Polyphenols, Black Tea Water Extract, Epigallocatechin Gallate (EGCG), Polyphenon E (Mitsui-Norin, Ltd.), Topical Polyphenon E (Epitome Pharmaceuticals Ltd.)
Category:	Phytochemical