yeah ,you are telling a very real & practical thing ,I really appreciate your thinking ,but normally what I am using is green tea of china from teanaga and as for the Chinese doctors prescriptions ,they are telling It is also very helpful in boosting immunity in the body of a person. Polyphones as well as Flavonoids are very helpful in building the immunity of a body as they are the agents that help in boosting the immunity. Vitamin C is also present in the Chinese Green tea that is helpful is keeping the flu away from the body of a person.