Health benefits of green tea unclear

While green tea may be the latest in health crazes, there's still little evidence of its benefits, researchers say.

Hundreds of studies have been done on the benefits of green tea, but the results of human tests are conflicting, says pharmaceutical researcher Heather Boon of the University of Toronto.

"Some of the studies suggest that people who take green tea may have less chance of getting cancer, but some of the studies found no difference," said Boon.

As well, people who drink green tea regularly may also make diet choices that improve their health, so it's hard to know if it's the tea that's making the difference, Boon said.

"Overall, there's no scientific evidence that green tea is proven to be effective in treating any health condition at this time," said Boon.

Any studies that have shown benefits from green tea have required subjects to drink up to 10 cups a day.

Dr. Stephen Lam of the B.C. Cancer Agency is conducting a placebo-controlled study on green tea, to test whether it can prevent cancer in long-time smokers.

"Tea is the second most common beverage in the world and has been consumed for centuries, so we know it's very safe," said Lam.

Lam's patients are taking pills with the equivalent of 10 cups of tea antioxidants. He says early results suggest the supplements appear to lower cholesterol and blood pressure.

Believers in the health benefits of green tea point to Chinese and Japanese lore, and to early scientific results, as evidence of its effectiveness.

"If you were to compare with, say, orange juice, we're looking at about 70 times the antioxidants," says Brian Takeda, owner of the Vancouver tea house Infuze.

Takeda predicts that green tea, especially the Japanese matcha, will sweep the continent because of its health benefits.