The majority of today's medical research involving tea is linked to green tea, but new studies are being conducted to include black tea. The Chinese have always believed that tea has strong medicinal uses. Through research, tea has been linked to the reduction of the risk of cancers, artherosclerosis, and heart disease because of its strong antioxidant properties. Tea derived from Camellia sinensis contains polyphenols, also called tannins, and small amounts of theophylline. Theophylline is an alkaloidal drug used in medicine as an anti-asthmatic, coronary vasodilator, and diuretic.
Theophylline is administered orally and rectally to treat asthma.
It facilitates breathing by relaxing the bronchioles in the lungs. It is given by injection to treat congestive heart failure, and orally to act as a diuretic by inhibiting reabsorption in the kidney tubules. Most theophylline is chemically synthesized, but potential exists for the use of natural theophylline. The mechanisms of tea's broad cancer chemopreventive effects are not yet completely understood. However, frequent consumption of green tea enables the body to maintain a high level of tea polyphenols so regular tea consumption can help protect against various types of cancers and other various types of oxidative stress.