While coffee appears to have both positive and negative health effects, especially green tea is basically a superfood.. but according to TSCC it's not so. When I've asked about this in various situations, the response has always been: "We don't fully understand how the human body works." Right.
After about 12,000 years of drinking tea, I think we have a pretty good idea of what it does for the human body.
There aren't many things that we know better, actually.
The reaction against "hot drinks" was part of the early temperance movement in the U.S. Members of the "Cold Water Army" took a pledge against hot drinks on the fear that they were entry drugs to hard liquor.