Tea for two — plus several hundred
In the e-Alert “Tea Off” (4/27/05) I told you about laboratory research that revealed how green tea may inhibit an enzyme that promotes cancer cell growth.
In 2003 a team of researchers from the Department of Preventive Medicine at the University of Southern California (USC) took green tea research out of the laboratory and into the homes of hundreds of women, with promising results concerning the prevention of breast cancer.
The USC team interviewed almost 1,100 Asian American women (aged 25 to 74) living in Los Angeles. 501 women had been diagnosed with breast cancer, and 594 were cancer-free.
Between 1995 and 1998, each subject was interviewed in person to determine a wide variety of factors, including food and beverage intake, personal medical history, family health history, and general lifestyle details such as smoking habits and alcohol intake. An examination of the data showed that women in the non-cancer group were much more likely to be regular green tea drinkers. In fact, on average, those who drank at least 8.5 milliliters (less than half a cup) of green tea each day, had a reduced breast cancer risk of nearly 30 percent. Those who consumed more than 8.5 milliliters reduced their risk even more.
But while more may be better when it comes to green tea, a high intake comes with a note of caution. EGCG is a type of flavonoid that’s abundant in green tea and is believed to be the active ingredient responsible for fighting cancer. But high levels of EGCG may reduce folate levels. The average green tea drinker can address this by increasing dietary sources of folate (chicken liver, lentils, asparagus and spinach) and by taking a folic acid supplement.
Pregnant women, however, should be cautious about green tea intake because low folate levels increase the risk of causing neural tube disorders to unborn children. Patients with cardiovascular problems also need to keep folate levels high.
“Low Carb Out, Slow Carb In?” Daniel DeNoon, WebMD Medical News, 5/11/05, my.webmd.com “Green tea and risk of breast cancer in Asian Americans” International Journal of Cancer, Vol. 106, No. 4, 574-579, 9/10/03, interscience.wiley.com