5-8 cups of green tea is a lot...especially if you are drinking tea with a higher caffeine content (some green teas can actually be very high in caffeine).
I recently wrote an article about how the health benefits of tea vary among different kinds of tea...it may be interesting to anyone who thinks that green tea is better (for any purposes). I'm pretty strongly convinced that it's not any better--rather, some teas are better for you than others, but there are black teas, green teas, oolong teas, pu-erh teas, and more which are beneficial.
What do others think?
(Note: Link to site selling tea removed by EmpowHer moderator in accordance with solicitation policy.)