For definition of Groups, see Preamble Evaluation . Tea is an aqueous infusion prepared from the dried leaves of Camellia sinensis , which has been consumed since ancient times in Asia and since the late seventeenth century in most other parts of the world. Tea is the most widely consumed beverage in the world. Annual tea consumption varies from country to country, ranging from a high level of about 3 kg per caput to negligible values in many countries. World consumption is approximately 0.5 kg per caput .
Green tea is the primary form consumed in China, Japan and some Middle Eastern countries.
Some black and green teas have traditionally been flavoured with natural agents such as oil of bergamot and jasmine flowers. Tea was tested for carcinogenicity in one study in rats by repeated subcutaneous injection of a total aqueous extract of tea leaves. A nonsignificant increase in the incidence of local tumours was observed. In a number of studies, various known carcinogens were administered by different routes either simultaneously or sequentially with tea or its constituents by various routes. N -nitrosoguanidine, within a limited period of observation.