"Matcha green tea has many antioxidants."

For years, studies have indicated that the antioxidants in green tea offer protection against diseases, including cancer, and even fight dental cavities. One of the most beneficial of these antioxidants is called epigallocatechin gallate. At the University of Colorado at Colorado Springs, [scientiest] used the chemical separation technique known as micellar electrokinetic chromatography to analyze matcha and a green tea commonly available in U.S. markets. The researchers found that samples of matcha had 200 times the concentration of epigallocatechin gallate in the common U.S. tea. Although most green teas are prepared in the familiar way-by steeping leaves in water-matcha is prepared by mixing hot water with powdered leaves. This is probably why matcha contains so much epigallocatechin gallate.

Science News, Apr 12, 2003