Green Tea Time
By Deborahann Smith
Tea is the world's most consumed beverage, although you might not think so from the number of coffee shops popping up on street corners across the country. Perhaps all those people waiting in line for cappuccinos and lattés haven't heard that drinking green tea can fight infections, cancer, heart disease and high blood pressure as well as help control inflammation and promote weight loss.
The Tale of Tea
Tea comes from the leaves of the common tea plant (Camellia sinensis), an evergreen shrub native to China. There are three basic types of tea: black, green and oolong. What distinguishes them is the process by which they are made. Black tea is made by fermenting and roasting the leaves, which gives it its characteristic dark color and rich taste, but also destroys some of the nutrients contained in the original plant. Oolong, however, is only partially fermented. Green tea, on the other hand, is lightly steamed, so it retains the chlorophyll of the leaf—hence, the green color—and most of the healing compounds as well.
Sometimes called a nutraceutical—a component of food that has a pharmacological benefit—green tea is full of compounds called polyphenols, which have shown significantly stronger antioxidant effects than vitamins C and E. Polyphenols also contain antibacterial and anticancer properties and can boost muscles' antioxidant enzymes, says James Duke, Ph.D., author of The Green Pharmacy Herbal Handbook (Rodale, 2000).
Green Tea Science
The number of studies conducted worldwide on this simple green beverage—more than 100 in the last year alone—is impressive. "Green tea has been researched for the last 15 years," says Mindy Green, director of education at the Herb Research Foundation, based in Boulder, Colo. "It's been studied mainly for its effects on cancer and dental caries. A recent discovery is that green tea is also a good herb for weight loss because its thermogenic ability to produce heat in muscle and fat allows calories to burn faster," says Green.
Also notable among the findings is green tea's capacity to lower blood pressure, reduce the risk of several forms of cancer and decrease incidences of heart disease, especially atherosclerosis. An article published in Alternative Medicine Review (2000, vol. 5) cited that green-tea polyphenols have demonstrated significant antioxidant, anti-carcinogenic, anti-inflammatory, thermogenic, probiotic and anti-microbial properties in numerous studies.
It's long been documented that the polyphenols in green tea fight bacteria such as E. coli and help prevent the plaque buildup that leads to cavities, oral cancers and gum disease. Other significant research reports that when applied topically, green tea may protect against a variety of skin disorders, including melanoma and other skin cancers (European Journal of Cancer; 2000, vol. 36; and Journal of Dermatology, 2000, vol. 27). Additional research has suggested even more uses for green tea. For example, one Chinese study showed that green tea lowered serum and liver cholesterol levels (Life Science, 2000, vol. 66). Green tea has also been found to support liver health. In fact, many health practitioners recommend adding green tea to liver-detoxification programs because it helps cleanse the liver, offers energy support and promotes clear thinking.
How much green tea do you have to drink to get therapeutic benefits? "The research recommends two to five cups a day," says Green, who notes that while green tea contains caffeine, one cup has only 15 mg of caffeine as opposed to 85 mg in a cup of coffee. Even so, if you're caffeine-sensitive, green tea is available decaffeinated with all the healing properties of the caffeinated brew.
Deborahann Smith is author of several books including Work with What You Have: Ways to a Creative & Meaningful Livelihood (Shambala, 1999) and a frequent contributer to Delicious Living.