Green Tea May Reduce the Risk of Breast Cancer
Results from a small pilot study suggest that regular green tea drinkers had lower blood estrogen levels, while regular black tea drinkers had higher blood estrogen levels.
10/05/07 While tea has been used as an alternative medicine in China for the last several thousand years, it is only recently that the Western hemisphere started to take notice of the beverage¹s potential health benefits, according to University of Southern California researchers. Now, tea is being hailed as a miracle elixir with the power to do everything from lower stress hormones and sooth the symptoms of PMS to protect against disease.
Although many of the claims are unproven, tea has been shown to reduce the risk of certain kinds of cancer, says Carol Koprowski, Ph.D., R.D., assistant professor of preventive medicine at the Keck School of Medicine of USC.
The tea that has been studied the most is green tea, she notes. Its one of the few teas out there that has been shown to have antioxidants that may protect against cell damage Epidemiologist Anna Wu, Ph.D., professor of preventive medicine at the Keck School, is studying the relationship between green tea consumption and breast cancer risk. An earlier study about breast cancer risk among Asian-American women showed that green tea intake had a strong protective effect, while the more commonly consumed black tea had no effect at all, she says.
While both green and black teas come from the same Camellia sinensis plant native to Asia, the leaves are processed differently. Black tea leaves go through a fermentation process that strips the plant of its natural polyphenol compounds, which are believed to give the tea its antioxidant properties, Wu says.
Results from a small pilot study suggest that regular green tea drinkers had lower blood estrogen levels, while regular black tea drinkers had higher blood estrogen levels. Higher levels of estrogen are associated with breast cancer risk, Wu explains.
While green tea is gaining in popularity around the world in part due to reports of its disease fighting properties, consumption still lags far behind black tea in most cultures. Regardless of whether the benefits are as widespread as some reports claim, a few cups of either green or black tea is a smart addition to a diet as a replacement for high-calorie sodas and fruit drinks.
Wu, a life-long black tea drinker, says she hasn¹t given it up but now drinks at least one cup of green tea a day as well.
