Consumption of green tea may help prevent cancer, suggest epidemiological studies conducted by researchers at the University of Toledo, Ohio, USA. Green tea contains chemicals called cathechins, including epigallo-cathechin-3 gallate (EGCG). EGCG inhibits urokinase (uPA), an enzyme which promotes cancerous growth. Researchers say that cancers need enzymes like uPA to invade cells and start metastases