Researchers from the University of California, Los Angeles, analyzed data from nine studies involving a total of nearly 195,000 people. Findings: Compared with people who drank less than one cup of tea daily, those who drank at least three cups daily of green or black tea (both of which come from the Camillia sinensis plant) had a 21% lower risk for stroke… risk dropped 42% for those who drank six or more cups of green or black tea daily. It is the flavonoid epigallocatechin gallate and the amino acid theanine, both of which are found in green and black teas, that might reduce stroke risk, researchers say.
Note: Though not included in the study, oolong tea and white tea (but not herbal teas) also come from the Camillia sinensis plant and therefore may have similar stroke-preventing benefits. There was not enough data on decaffeinated tea to include it in the study.