This compares to a cup of black tea which has about 40 milligrams and a cup of brewed coffee which has 100 milligrams. With interest in green tea surging, a number of decaffeinated products have come onto the market. The obvious question is whether the decaffeination process affects the potential health benefits of green tea. Several studies have identified potentially powerful antioxidants in green tea. One of these antioxidants, known as EGCG is found only in green tea leaves.
Researchers theorize that antioxidants contribute to good health by neutralizing free radicals.
Free radicals are believed to help cause certain diseases such as cancer. The catechins in green tea are also believed to work in other ways to prevent some types of cancer as well as cardiovascular disease. The answer to the question depends on how the tea was decaffeinated. There are two accepted methods of decaffeination in the United States. One process uses a solvent, Ethyl Acetate, to remove the caffeine.