Green tea is a type of tea that is made from Camellia sinensis leaves that have not undergone the same withering and oxidation process used to make oolong and black tea. Green tea originated in China, but its production has spread to many countries in Asia.
Several varieties of green tea exist, which differ substantially because of the variety of C. Sinensis used growing conditions, horticultural methods, production processing, and time of harvest.
Regular green tea is 99.9% water, provides 1 Calorie per 100 mL serving, is devoid of significant nutrient content (table), and contains phytochemicals, such as polyphenols and caffeine. Polyphenols found in green tea include epigallocatechin gallate (EGCG), epicatechin gallate, epicatechins, and flavanols.