It should be emphasized that only about 10% of the 500 studies were done on
humans; the rest were done on mice or in test tubes. In addition, some studies
were done with the compound EGCG rather than with green tea. Most studies
showed that the more tea consumed, up to ten cups a day, the better. Even
though many studies are only suggestive, none has shown that green tea does any
harm so drinking five to ten cups a day seems like a good idea.