Research indicates that tea may work against heart attacks, stroke, and thrombosis. Tea contributes to this in several ways. It does so in a general way through its role as gentle stimulant to the heart and circulatory system. Secondly, it appears to keep the blood vessel walls soft. Thirdly, there is evidence that the phenols in tea inhibit the absorption of cholesterol in the digestive tract, which could help decrease the cholesterol in the bloodstream. Fourthly, it may decrease the blood's tendency to form thrombi, or unwanted clots. Often several of these functions operate together against stroke or heart attack. Strokes and thrombosis often occur because the blood vessels have lost their elasticity. Rutin, found in green tea, has long been prescribed to keep these walls soft.

Green tea has turned out to be a double-barrelled threat to tooth decay because of the natural polyphenols (tannin) and the fluoride it contains. Polyphenols tend to reduce the formation of plaque, while fluoride strengthens tooth enamel so that it can resist decay.

Considerable research is being carried out on the role of tea drinking in preventing cancer. Out of 25 papers related to health presented at the Hangzhou Symposium, seven reported on research on cancer and tumors. Green tea seems to get the best results, with Lung Ching Preferred. Stomach cancer, the number one cause of death in Japan, is at its lowest rate in Shizuoka prefecture along the coast southwest of Tokyo. One explanation is that Shizuoka is a tea-growing district and its inhabitants drink large amounts of green tea.

Researchers believe that green tea has an effect against cancer because it inhibits the formation or action of cancer-causing substances. Green tea may block the action of nitrosamines which can cause cancer, said Dr. Han Chi, and associate professor at the Institute of Nutrition and Food Hygiene under the Chinese Academy of Preventative Medicine. In a test of 145 types of tea, she and her colleagues rated green tea highest, with a blocking rate of 90 percent. Brick, Jasmine, oolong, and black tea followed in that order.

In China it is widely stated that green tea is a source of vitamin C. Since this vitamin is destroyed by heat and tea is made in hot water, this statement seems somewhat contradictory. However, recent tests in China have found that heat destruction of vitamin C does occur, but not in tea. Something in tea, as yet undetermined, apparently helps stabilize vitamin C. The amount of vitamin C contained in green tea varies greatly depending on growing conditions, the age of the leaves at picking, and how long they have been stored. According to Chinese calculations, typical green tea made with three grams of dry leaves to a cup should yield about six milligrams of vitamin C in three infusions in water at 158 to 212 degrees Fahrenheit (70 to 100 degrees centigrade). Eighty-five percent of the vitamin C is released in one five minute infusion at 176 degrees Fahrenheit (80 degrees centigrade). Tea also contains vitamins B1, B2, K and bioflavonoids plus niacin, folic acid, and manganese, but in such small amounts as to be negligible.

Another way tea may help fight cancer is through preventing cell mutation. The antioxidant actions of the polyphenols in green tea inhibit mutation of the DNA in healthy cells, which can cause them to become cancer cells. In rats injected with a cancer-causing substance and fed green tea, cancer did not develop, but it did in the control group without tea.

An antioxidant made from green tea applied to the skin significantly inhibited growth of induced skin cancer in mice. In similar tests in Fujian province, green tea markedly decreased the incidence of Lung cancer in rats. It seems to be the epigallo catechin gallate (EGCC) that reduces the occurence of aberrant DNA replication in epithelial cells.

Some researchers claim tea acts as a mild germicide in the digestive tract to help prevent food poisoning and diseases like cholera, typhoid, and dysentery. "The antibacterial effects of tea have been well documented in Chinese scientific literature," writes Dr. Albert Y. Leung in Chinese Herbal Remedies. "Green teas have stronger effects than black teas. They are effective against any types of bacteria, including those that cause dysentery, diphtheria, and cholera... in treating bacillary dysentery, amoebic dysentery, acute gastroenteritis (inflammation of stomach and intestine), and enteritis (inflammation of the intestine)."

When pregnant or nursing only small amounts of green tea should be used, it may also interfere with the action of MAO inhibitors and blood thinning medication. Also the consumption of green tea may interfere with the absorption of medicines. This article is intended to be for information about the nutritional benefits of green tea only and should not be regarded as medical advice in its own right. You should seek the assistance of a qualified physician if you require medical advice on any condition mentioned in this article.