How It Works
Green Tea Polyphenols (GTP), particularly EGCG or EGCg (epigallocatechin gallate) are thought to inhibit an enzyme required for cancer cell growth, and also kill cancer cells with no ill effects on healthy cells. (1)
Dry green tea leaves are about 40 percent polyphenols by weight, and it is suggested the most potent of these is EGCG. A team of scientists at Purdue University determined: “In the presence of EGCg, the cancer cells literally failed to grow or enlarge after division then presumably because they did not reach the minimum size needed to divide they underwent programmed cell death, or apoptosis.” EGCG, an antioxidant, is considered many times more potent than the Vitamin E or Vitamin C antioxidant properties. In a 1997 study, researchers from the University of Kansas determined that EGCG is twice as powerful as resveratrol, which itself is known to kill cancer cells (see the Grape Cure page).
Green Tea is also theorized to be a key element of cancer prevention. (2) Researchers have known for years that the incidence of prostate cancer is considerably lower in Asian countries. One possible explanation advanced by scientists is the high consumption of plant foods among Asian populations. Another is the growing number of laboratory studies indicating that green tea — the most popular tea in China, Japan and other Asian countries — has anti-tumor effects.” (4) Black tea is more popular in Western countries.
Worldwide, about 80 percent of the tea consumed is black tea. Both teas come from the same plant (Camellia sinensis). Black tea is fermented; green tea is not. Next to water, tea is the most widely consumed beverage in the world. Green tea contains more polyphenols — chemicals that act as powerful antioxidants and nontoxic, cancer preventive agents — than black tea. (3) It has been speculated that the low lung cancer rate in Japan — despite the high rate of smoking — is due to green tea consumption.