PRAGUE, June 22, 2006 (RFE/RL) -- "When the days are very hot I drink green tea, because when I drink another tea it doesn't quench my thirst, but green tea does," says one Bishkek, Kyrgyzstan, resident who asked to be identified only by his first name, Alisher. "I like to drink green tea when it's hot, and I've heard it's good for your health."
Millions of people already drink it for pleasure, or thirst.
But as Alisher points out, there's growing evidence green tea is good for you, too.
Reducing Cancer Risk
"I can tell you that if you are a [laboratory] rat, you should be drinking lots of tea, it will reduce your risk of cancer," says Jeffrey Blumberg, a nutritional scientist at Tufts University.
"There have been a number of laboratory studies that have shown that green tea may have an effect on inflammatory conditions like arthritis, on cognitive problems like Alzheimer's and Parkinson's diseases," Blumberg continues. "Some studies have suggested that people who consume more tea have a lower risk of bone fracture, that is it may reduce osteoporosis, and there have been a number of studies particularly from the U.K. that suggest that adolescents and teenagers who drink tea have a lower instance of dental cavities. But the strongest reports to date are those that suggest that tea may reduce our risk of heart disease."
The Asia Phenomenon
In particular, researchers say, green tea might explain why some Asian countries have high smoking rates, but relatively few deaths from heart disease or lung cancer, both of them smoking-related diseases.
Japan, for instance, has about half the death rate from heart disease as the United States, even though the Japanese smoke far more cigarettes.
Bauer Sumpio calls this the Asian paradox. Sumpio, who published a review article on the topic last month, says the explanation might lie in all the green tea people in Asian countries drink.
"They sit at their desk or wherever they work, with a big tall glass or jar and in the beginning of the day they put a handful of green tea leaves there and add hot water in it, and when they finish drinking that they'll add more hot water to it and they do that throughout the day," Sumpio says.
How It Works
Sumpio, a vascular surgeon at Yale University, says green tea contains chemicals called polyphenols -- and one in particular called epigallocatechin gallate (EGCG).
EGCG is an antioxidant that neutralizes harmful particles known as "free radicals" that can damage cells in the body.
"It's thought that this is what confers beneficial effects in terms of both the cardiovascular system as well as in some cancer cells, there's a lot of evidence that some of these cancer cells, at least in the laboratory, can be inhibited from growing when you add these polyphenols to them," Sumpio says.
The evidence that green tea is good for you is not yet rock solid.
Blumberg of Tufts says all tea -- whether green, white, oolong, or black -- comes from the same bush, so the health benefits should actually be the same.
Whatever the case may be, its reputed health benefits have led to green tea growing in popularity in some western countries like the United States.
Kevin Moore sells green tea all around the world from his company in Fukushima, Japan.
"I've been involved in Japan for 20 years; my wife is Japanese," Moore says. "When I was going to college at Arizona State University, I was looking for a side business to do. As I was familiar with Japan and green tea -- it was very hard to find a good green tea in 1998, actually it's still hard to find a good green tea in the United States -- I started doing it as a side business, and I guess my timing was right as it's boomed ever since then."
Green tea, though, is not everyone's cup of tea.
But there's good news for those who don't like the taste.
Other foods -- chocolate, red wine, apples, and vegetables like turnips and cabbage -- contain some similar chemical compounds.
(Ainura Asankojoeva of RFE/RL's Kyrgyz Service and staff at the Bishkek bureau contributed to this report)