An established South African tea can offer more than 50% more antioxidants than green tea, according to Alvaro Viljoen, from the pharmacy department at the University of the Witwatersrand . Speaking to WebMD, Viljoen added that the tea is also extremely rich in vitamin C, while being caffeine-free and low in tannins: "If you don't capture a market with those attractions, I don't think much else will sell it."