What It Is; Why It Works
Green Tea contains caffeine, which stimulates the central nervous system, and tannins, which combat diarrhea. Taken in moderation, it settles the stomach and has mild stimulant effects. In excess, it can cause insomnia and digestive problems.
Green Tea's cancer-fighting properties have been verified in two recent studies. In China, researchers found that as tea consumption increased, the risk of cancer declined. Women who drank the most tea enjoyed a 33 percent reduction in the risk of colon cancer, a 43 percent reduction in the risk of rectal cancer, and a 47 percent reduction in the risk of pancreatic cancer. In Japan, a study of 472 breast cancer patients revealed a significant drop in the rate of recurrence among those drinking 5 or more cups of Green Tea daily.
Green and black tea come from the same plant and differ only in their method of production. Green Tea is dried for a shorter time, and is heated sooner to prevent fermentation. Green Tea is produced in China and Japan; black tea comes from India, Sri Lanka, and Kenya. The plant is also cultivated in Indonesia, Turkey, Pakistan, Malawi, and Argentina.
Take Green Tea cautiously if you have a weak heart, kidney disease, an overactive thyroid, a susceptibility to spasms, or a tendency to anxiety or panic attacks.
Source: The American Institute for Cancer Research (AICR).
Green tea contains caffeine. Although green tea's caffeine content is less than that of black tea or coffee, in fact, three or four cups of green tea contains approximately the same amount of caffeine found in a single cup of coffee, it is important to be aware that caffeine has deleterious effects in large doses.
For this reason, people who suffer from heart or kidney problems, stomach ulcers or anxiety should avoid green tea. Pregnant and breastfeeding women should not drink green tea.