Study Looks at Green Tea Benefits

(November 6, 2009) - Although scientists are reluctant to officially endorse green tea as a cancer prevention method, evidence continues to grow about its protective effects, including results of a new study, which suggests some reduction in oral cancer. (Read about "Oral Cancer") The study is published in Cancer Prevention Research, a journal of the American Association for Cancer Research

Researchers tested green tea extract taken orally for three months at three doses among 41 patients: 500 mg/m2, 750 mg/m2 or 1,000 mg/m2.

The researchers assessed clinical response in oral pre-malignant lesions and found 58.8 percent of patients at the highest doses displayed clinical response, compared with 18.2 percent among those taking placebo. They also observed a trend toward improved histology, and a trend towards improvement in a handful of biomarkers that may be important in predicting cancer development.

Patients were followed for 27.5 months and at the end of the study period, 15 developed oral cancer. Although there was no difference in oral cancer development overall between those who took green tea and those who did not, patients who presented with mild to moderate dysplasia had a longer time to develop oral cancer if they took green tea extract.

Although encouraged by the results, Vassiliki Papadimitrakopoulo, M.D, the lead researcher, cautioned against any recommendations that green tea could definitely prevent cancer.

"This is a phase II study with a very limited number of patients who took what would be the equivalent of drinking eight to 10 cups of green tea every single day," said Papadimitrakopoulo. "We cannot with certainty claim prevention benefits from a trial this size."