According to a study on mice from Case Western Reserve University’s School of Medicine, antioxidants in green tea may protect from rheumatoid arthritis and reduce the severity of the symptoms. The study was published in the Proceedings of the National Academy of Sciences (April 13, 1999 vol. 96 no. 8 4524-4529).

Antioxidants in green tea, known as polyphenols, may protect the body from the oxidative stress that causes the disease. Oxidative stress is caused by free radicals, which are like chemical “bullets”. Antioxidants are like “bullet-proof vests”. Some of the polyphenols in green tea possess much more potent antioxidant activity than more well-known antioxidants like vitamin C and vitamin E.

The polyphenols were given to mice with a type of arthritis similar to rheumatoid in humans. Of the 18 mice that were given the green tea extract, only eight (44%) developed arthritis. The mice that received green tea polyphenols but got arthritis, had a less severe form of arthritis. All but one of the mice getting the green tea-extract (94%) developed arthritis. The extract given to the mice was an equivalent dosage to that of a human consuming four cups of green tea each day.