Connection Between Green Tea, Cancer Prevention Found

A new study of 1.6 million people has turned up “limited” proof that green tea can help avoid some kinds of cancer.

“We can say for certain that green tea consumption can never account for cancer prevention alone,” Dr. Katja Boehm of the Unconventional and Complementary Methods in Oncology Study Group in Nuremberg, Germany, said to Reuters Health.

“The lack of interventional studies in this field, where many health claims have been made in the past, is one of the most salient points of the review,” she said.

Boehm and her colleagues reviewed literature on green tea consumption and discovered 51 studies compatible for their research.

Only one of them was a randomized trial. The investigations of green tea use and cancers had “highly contradictory” results, Boehm and her team noted, with “limited evidence” that green tea could prevent liver cancer.

For prostate cancer, several studies implied a connection between drinking a lot of green tea and a lower chance of cancer, the researchers discovered. Bladder and lung cancer proof was “limited to moderate,” while there was some data that green tea might increase bladder cancer risk.

Forty-seven studies were conducted in Asia, Boehm and her colleagues wrote, where green tea is much more popular than other places.

“It is impossible to generalize the findings to the world more widely since the main bulk of evidence derives mainly from Asian cultures,” the researcher wrote.

To develop a better connection between green tea and cancer prevention, it will be important to conduct a “large, well-designed” study with adequate green tea consumption.”

“We need to aim at creating high-level evidence in this much talked about but little researched topic area. Funding and infrastructure for clinical trials remain major challenges for the future.”

Nonetheless, they wrote, people who frequently drink green tea should go ahead and enjoy it.

“Drinking green tea appears to be safe at regular, habitual and moderate use, within its recommended dose of 1200 milliliters per day, which is about 5-6 average cups per day,” Boehm said.