This is good news, because tea offers important health benefits. Green tea was the first tea studied for its cancer-fighting benefits. The leaves of this tree contain chemicals called polyphenols, which give tea its antioxidant properties. Herbal teas are not derived from this leaf and so do not have this particular health-promoting chemical. The degree of processing determines whether a tea will be green, black or red.
Green teas are the least processed.
They are simply steamed quickly before packaging. Black and red teas are partially dried, crushed and fermented. The length of fermentation, which causes the leaves to blacken, determines whether the tea will be red or black. Regardless of the processing method, all teas contain polyphenols. Although oxygen is vital to life, it's also incorporated into reactive substances called free radicals.