Drinking green tea may do more than just thwart a head cold, according to research presented at the American Association for Cancer Research Second Annual International Conference on Frontiers in Cancer Prevention Research. Green tea already is believed to help lower cholesterol and prevent heart disease, fight bacteria and dental cavities, and possibly aid weight loss. New studies are now suggesting the various potential anti-cancer benefits of the age-old beverage.
"Laboratory studies have suggested that green tea consumption may produce many health benefits, including the prevention of cancer, but the beneficial effects in humans are not clearly known," said C.S. Yang, Ph.D., of Rutgers University, N.J.
"Research is now showing how this novel chemopreventive agent might work at the molecular level and in the human population," he added.
EGCG (epigallocatchin-3-gallate) is the most abundant and active chemopreventive agent in green tea, and has been associated with reduced risk of breast, pancreatic, colon, esophageal and lung cancers in humans. However, EGCG has a low oral bioavailability, meaning that to sustain effective levels for biological activity, individuals would need to drink at least seven to eight cups of tea a day, or ingest large amounts of green tea polyphenol extract.
As a first stop toward overcoming this problem, researchers from SRI International in Menlo Park, Calif., have successfully synthesized several EGCG analogs (a chemical compound structurally similar, but different in composition) that inhibit the growth of tumor cell lines with potencies equal to or greater than EGCG itself.
"These analogs are not only valuable tools to clarify how green tea may fight cancer, but are also potential chemopreventive drug candidates themselves, with perhaps better pharmacokinetic properties than have been seen with EGCG thus far," said SRI's Nurulain Zaveri, Ph.D., lead author of the study.
SOURCES:
Second Annual International Conference on Frontiers in Cancer Prevention Research, October 28, 2003, Phoenix, AZ
American Association for Cancer Research (http://www.aacr.org)
