Green tea extract has been found effective in preventing oral cancer, say researchers at The University of Texas M. D. Anderson Cancer Centre.
Green tea is rich in polyphenols, which have been known to inhibit carcinogenesis in preclinical models.
"While still very early, and not definitive proof that green tea is an effective preventive agent, these results certainly encourage more study for patients at highest risk for oral cancer," said Dr Vassiliki Papadimitrakopoulou, professor in M. D. Anderson's Department of Thoracic/Head and Neck Medical Oncology, and the study's senior author.
"The extract's lack of toxicity is attractive - in prevention trials, it's very important to remember that these are otherwise healthy individuals and we need to ensure that agents studied produce no harm," Papadimitrakopoulou added.
During the study, 41 oral leukoplakia patients were randomized to receive either green tea extract or placebo.
"Collecting oral tissue biopsies was essential in that it allowed us to learn that not only did the green tea extract appear to have benefit for some patients, but we pointed to anti-angiogenic effects as a potential mechanism of action," said Dr Anne Tsao, assistant professor in the Department of Thoracic/Head and Neck Medical Oncology, and the study's first author.
"While preliminary because our patient population was so small, this gives us direction for further study," Tsao added.
The study also showed that of those taking green tea at the two highest doses, 58.8 percent had a clinical response, compared with 36.4 percent in the lowest extract dose and 18.2 percent in the placebo arm.
"While these are encouraging findings, much more research must be done before we can conclude that green tea may prevent oral or any other type of cancer. It's also important to remind people that this trial enrolled very few participants who, at the highest dose levels took the equivalent of eight cups of green tea three times a day," said Papadimitrakopoulo.
"We need to further understand if green tea offers longer-term prevention effects for patients."
The study is published online in Cancer Prevention Research.