Cancer is a complex disease. Many factors contribute to cancer development, such as tobacco use, diet, lifestyle, the environment, and genetics. Two-thirds of all cancers are linked to tobacco use and dietary factors such as alcohol consumption and diet rich in high-fat foods. But, diet can also play an important role in lowering cancer risk. Population studies suggest that eating a diet rich in plant foods such as fruits, vegetables and tea is associated with lower risk for cancer. According to the American Cancer Society Guidelines on Diet, Nutrition and Cancer Prevention, people should eat a balanced diet that includes fruits, vegetables, and grains; limit their intake of high fat foods, particularly animal sources; be physically active to achieve and maintain a healthy weight; and limit consumption of alcoholic beverages (151).

Animal studies suggest that both black and green tea may help prevent or delay formation of tumors-specifically in the skin, lung, esophagus, stomach and colon. Tea appears to do this by preventing damage to cells caused by cancer-causing chemicals (69, 70,120) and by slowing down the growth rate of precancerous cells, as well as by enhancing the body’s ability to naturally kill precancerous and cancerous cells. Research has found that tea flavonoids protect cells from damage caused by free radicals and other carcinogens by acting as antioxidants and by helping the body rid itself of carcinogens. Studies also show that the flavonoids in tea help control progression of cancer by maintaining normal cell growth rate and by increasing the natural turnover of precancerous and cancerous cells. (122-125) Population-based studies have associated drinking tea with lower risk for a number of cancers. Based on data from the United States Centers for Disease Control and Prevention’s NHANES I Follow-Up study (NHEFS), researchers found that tea drinkers (1-2 cups per day) had about a 42 percent reduced risk of colon cancer as compared to non-tea drinkers. Men who drank more than 1 1/2 cups of tea per day were found to have a 70 percent lower colon cancer risk (128). The Iowa Women’s Study which followed post-menopausal women between the ages of 55 and 69 years of age for 12 years found that participants who drank two or more cups of tea per day had a 32 percent reduced rate of developing digestive cancer and a 60 percent reduced rate of urinary tract cancer(129).

Studies in people are underway at medical centers in the US, Japan and China to determine the potential of tea flavonoids in cancer prevention. Preliminary studies have found that tea flavonoids reduce measures of oxidative damage in people (69,70, 152) and may prevent progression of precancerous lesions of the mouth (124)

*While tea is a naturally rich source of antioxidants, it is not a substitute for fruits or vegetables which provide a wide range of antioxidants and essential vitamins and minerals. Please consult your doctor regarding a diet/nutritional plan that is right for you.