Green Tea is a great alternative to coffee for that caffeine buzz, since each cup contains anywhere between 35-100 milligrams of caffeine, depending on how long it's been steeped.
Green tea is also a great source of antioxidants—called catechins—that help support immune function, cardiovascular health, and fat loss.
Green tea extract is a herbal derivative from green tea leaves (Camellia sinensis). Containing antioxidant ingredients – mainly green tea catechins (GTC) – green tea and its derivatives are sometimes used as dietary supplements and in alternative medicine.
Numerous epidemiological studies show that regular consumption of green tea has many positive effects on overall health, including preventing and resisting cancers, preventing radiation, anti-bacteria, relieving fatigue, refreshing mind, protecting teeth and clearing eyes，and reducing high blood pressure, blood sugar, and blood fat.