Studies Reinforce Possible Anticancer Properties of Tea

According to the results of a studies, several compounds in tea show anticancer potential. These studies were conducted by researchers at the USDA-ARS Western Regional Research Center, Albany, CA; The Center for Traditional Microorganism Resources, Keimyung University, Daegu, South Korea; College of Human Ecology and Kinesiology, Yeungnam University, Gyeongsan, South Korea; and the Department of Food Service Industry, Uiduk University, South Korea. The results of this research were published in the Jan. 24 issue of the Journal of Agricultural & Food Chemistry (see http://pubs.acs.org/cgi-bin/abstract.cgi/jafcau/2007/55/i02/abs/jf062276h.html).

Researchers studied the anticancer potential of theanine, an amino acid, in 15 commercial black, green, specialty and herbal tea leaves. In order to define relative anticarcinogenic potencies of tea compounds and teas, they evaluated nine green-tea catechins and three black-tea theaflavins in addition to theanine. The results showed that most tea catechins, theaflavins and theanine reduced the cell count of several types of cancer. However, statistical analysis of the data showed that the anticarcinogenic effects of tea compounds and of tea leaf extracts vary widely and that efficacy is directly related to the concentration of those compounds. Analysis showed that flavonoid levels of the teas did not have a direct effect on anticarcinogenic activities.

These results led the researchers to conclude that tea ingredients show good anticancer potential and that consumers may benefit more by drinking both green and black teas.