Green Tea

Green tea (Camellia sinensis) has been used by the Chinese for thousands of years as a medicinal remedy to treat such ailments as migraine headaches, body ache, poor digestion, and to improve general well-being and life expectancy.
Green tea is rich in bioflavonoids,and one of its main uses is fighting free radicals in your body. Green tea also contains high level of polyphenols (a bioflavonoid), and it's also a rich source of EGCG (an antioxidant), which is over 200 times more potent than vitamin E in fighting free radicals and pro-oxidants.
Green tea is now found to be useful in the fight against cancer, see this BBC article entitled Green tea extract 'is cancer aid'

The EGCG in green tea is said to protect against digestive and respiratory act infections. Also since the leaves contain a natural fluoride, may be helpful in preventing tooth decay. It can help to regulate blood sugar and insulin levels. Green tea may also prevent and help reduce the severity of osteoarthritis. Studies have shown that if you consume approximately four cups of green tea a day you may be able to protect yourself from developing arthritis, and if you already have arthritis, consuming green tea can help to diminish the inflammation it causes.

Green Tea can ease mental fatigue and has been used in treating digestive tract infections. It is also said to treat migraine headaches, and since the leaves contain a natural source of fluorine, it may be helpful in preventing tooth decay. It can help to regulate blood sugar and insulin levels.

The reason other Chinese and Indian teas don't posses similar health-giving properties, is despite Green, oolong, and black tea all being made from the leaves of the Camellia sinensis plant. What sets green tea apart is the way it is processed. Green tea leaves are steamed, which prevents the EGCG compound from being oxidized. By contrast, black and oolong tea leaves that have been left to ferment. Which results in the EGCG being converted into other compounds that are not nearly as effective in preventing and fighting various diseases.

To sum up, some of the medical conditions in which drinking green tea is reputed to be helpful are: cancer, rheumatoid arthritis, high cholesterol levels, cariovascular disease, infection, impaired immune function.

Properties:
analgesic, anti-viral, antioxidant, astringent, cardiotonic, carminative, digestive, diuretic, expectorant, nervine, stimulant, stomachic.

A source in the UK is available here

Chinese Green Tea in USA

Another great source is here