The CancerWeb Report, What's New In Cancer: November, 1996
Head and Neck Cancer

• Dietary flavonoids may have a preventive action against oral cancer, in rats at least - The flavonoids are substances that are found in a wide range of plants. A diet that includes plenty of fruits and vegetables may provide as much as 1 gram per day of these compounds. One of the flavonoids in particular, namely quercetin, has been studied intensely. It produces mutations in bacteria and increases the incidence of intestinal, bladder and liver tumors in rats, yet it has also been shown to inhibit the growth of cells from squamous cell tongue and other human cancers, and to antagonize the formation of breast, colon and skin cancers in rats that were treated with carcinogens. Similar anticancer actions have been found for the chalcones, another type of flavonoid. Researchers at the Gifu Medical School in Japan described a 68-88% reduction in oral tumor induction by the carcinogen 4-nitroquinoline-1-oxide in rats given dietary quercetin, chalcone, or 2-hydroxychalcone at 500 ppm in their diet over a 10-week period. The results of their study, published in the November 1, 1996 issue of Cancer Research, also indicated that these flavonoids reduced the rate of proliferation of cells in the mouth, and the levels of certain chemicals, polyamines, that are associated with cell division. (Makita, Cancer Res 56:4904, 1996)