The Japanese have a tea study
 

One cup of coffee and four cups of green tea daily lead to a lower risk of stroke. Not yet replicated on Caucasians. It would at least lead to a lower risk of sleeping through the night. Toci

Thanks for the info. We drinks our green tea faithfully and is nice to know the prescribed amounts and the coffee ratio. I know the Chinese folks seem to drink it all day long. I aint never seen a sick Chinese person that I can recall. It must work.

Green tea is a very popular drink in Japan. But some people drink more than others do. Women who drink five or more 3.4-ounce cups of green tea every day cut their risk of heart disease by 31 percent compared with women who drink one or fewer 3.4-ounce cups. Men who drink this much green tea cut their heart disease risk by 22 percent.

I normally consumed 2 cups of coffee and and 2 cups of tea daily.