At the start of the study – and again five years later – 53,793 women completed questionnaires about their green tea intake. Over the course of 13.6 years, 581 subjects developed breast cancer. Analyzing their findings, the researchers found no link between green tea consumption and breast cancer risk.
Rich in antioxidants, green tea is thought to fight cancer by neutralizing free radicals (chemical byproducts known to damage DNA). However, research on green tea’s anti-cancer effects has yielded mixed results. For instance, a 2009 review of 51 studies (with a total of more than 1.6 million participants) found limited or conflicting evidence that green tea consumption could protect against cancers of the digestive tract, liver, stomach, colon, and pancreas.