What is Green Tea Extract?When we first learned of the incredible new discoveries concerning
green tea, we thought we were in for a long and tedious education on teas (we're all devoted coffee drinkers!). But we were pleasantly surprised (and our science writer quit coffee in favor of green tea!). Don't be daunted by the apparent myriad varieties of tea; by "tea" we mean the leaf of the plant, Camellia sinensis - other so-called "herbal teas" (a misnomer because Camellia sinensis is an herb) are meant to be any infusion other than that of Camellia sinensis. There are really only three categories of teas: green, oolong, and black. Each of these is the leaf of Camellia sinensis and differs only in duration of fermentation: "black" is fully fermented, "oolong" is partially fermented, and "green" is not fermented at all, only steamed. Types of tea such as Ceylon and Darjeeling refer to the region in which they are grown.
For What, and How is Green Tea Extract Used?
What is amazing about
green tea is its reported ability to ward off many types of cancer. Much of the initial evidence that green tea is anti-carcinogenic is based on epidemiological studies which show lower rates of many types of cancer among populations such as Japan and China that drink green tea as part of a daily cultural habit. Recently, however, controlled studies on green tea extract have yielded impressive results, identifying the polyphenol (-)-epigallocatechin gallate (EGCG) as the responsible component. EGCG is able to force certain cancer cells into a situation in which, incredible as it may seem, they must die or be killed; the cancer cells die in a sort of cellular suicide, a condition scientists call "apoptosis". Further evidence shows EGCG as having an inhibitory effect on the enzyme, urokinase, which is required for tumor formation, thus preventing the formation of tumors in the first place.3,4,8-11,14-20,22-27,35
Not only are the polyphenols in green tea protective against certain cancers, but they are also potent antioxidants. Green tea's antioxidants have been shown to be highly beneficial to the heart - they help prevent the oxidation of LDL cholesterol.29-33
Things to know about Green Tea: Epidemiological studies have examined green tea drinkers; controlled studies have largely been done on the extract of green tea. Both are beneficial. One cup of green tea contains from 100-200mg of EGCG. Green tea should not be steeped in boiling water, but hot water (around 160-200 degrees). Use 1 Teaspoon of loose tea per cup, and a little more than 1 cup of water. Decaffeinated green tea does not show the same benefits as green tea left in its natural state. Adding milk negates green tea's beneficial properties. Black tea may increase the incidence of certain cancers. More than 5 cups a day may increase your odds for pancreatic cancer; 1-4 cups shows only benefits, so 1 or 2 cups a day is probably just right.
