Introduction to tea catechins as antioxidant compounds Tea is a rich source of catechins, which are known for their potent antioxidant activity. These compounds exist in four main forms, namely EC, ECG, EGC, and EGCG. Together they contribute to the various health benefits of tea. Catechins act by neutralizing dangerous free radicals that can cause cellular damage and inflammation. This helps prevent chronic diseases such as cancer, heart disease and Alzheimer's in the long run.