Rosemary is a very rich source of antioxidants, which makes it an excellent anti-inflammatory agent. This also makes rosemary tea a great blood-purifying agent, which in turn helps to improve blood circulation and boosting the immune system. Not just that; rosemary tea also contains antioxidants which help in fighting free radicals which in turn help in reducing the incidence of cancer and other life threatening illnesses. Rosemary is also a traditional medicine for treating indigestion. Drinking rosemary tea for a prolonged period of time has been shown to improve digestion and reduce the incidence of digestive problems.