Where there're sponsors there're studies. Don't trust those. Not saying that they're scientifcly wrong, but similar studies have been made for red wine and dark chocolate. Also, there was / is the green tea trend. You need to take all effects of a substance into account when judging the health benefits.

If you want to do something good for your health, drink herbal tea. But why do most of the people prefer coffee or green / black tea? Or drink red wine or eat lots of dark chocolate. Because those are stimulants.