A chemical found in green tea appears to increase the effectiveness of cancer drugs, according to Japanese researchers. The finding lends support to research which suggests that green tea has anti-cancer properties. Masami Suganuma and colleagues at Japan's Saitma Cancer Research Institute found that epigallocatechin gallate (EGCG), one of many polyphenols contained in green tea, increases the potency of the anticancer drugs sulindac and tamoxifen. EGCG and sulindac killed two to eight times more cancer cells than sulindac alone. Adding the polyphenol to the breast cancer drug tamoxifen doubled the effectiveness of the treatment, the team discovered.