The book The Chemistry of Calmsays …
“Make pure water your main beverage. … If you like green tea, you can drink it throughout the day.” [page 69-70]
Green tea is our second most healthy beverage — second to water.
Unsweetened green tea can contain zero sugar. Its health benefit comes from its antioxidant capabilities. Green tea contains catechins such as epigallocatechin-3-gallate (EGCG) which inhibits cancer growth. Green tea is also good for the heart since it helps dilate blood vessels.[reference]
In his talk about nutrition and cancer, Dr. Donald Abrams says he drinks 4 cups of green tea each day. See video above.
Although green tea has relatively low caffeine as compared to coffee. If you are concerned about caffeine, don’t drink green tea before bed so as to not affect your sleep.