Next to water, tea is presently the most widely consumed beverage in the world. The three forms of tea, which are differentiated by processing method, are green, oolong, and black tea. Of these, green tea undergoes the least amount of processing, and it has been used for medicinal purposes for thousands of years. Green tea has become well known for its antioxidant, antimutagenic and anticarcinogenic effects. Other possible benefits include treatment of cardiovascular disease, diabetes, dermatological problems, obesity, and oral health problems.