Vitamin C's cancer preventative qualities have long been suspected, but the mechanisms by which it inhibits the disease have not been fully understood. Recently, researchers at Cornell University in Ithaca, N.Y., and Seoul National University in Korea discovered that vitamin C's anticancer activity may block the carcinogenic effects of hydrogen peroxide on intercellular communication. This recent research confirms that vitamin C is a potent cancer fighter; however, the scientists also found that the phytochemical quercetin works in the same manner but is even more powerful.
Quercetin, a natural antioxidant found in apples, red wine, grapefruit, onions and black tea, has been credited with reducing heart attack and stroke risk by protecting blood vessels against free radical damage. This research indicates quercetin may be an important player in the fight against cancer as well.
"Our results showed that quercetin had a more inhibitory effect than vitamin C on prevention of gap junction communication induced by hydrogen peroxide," said Chang Y. Lee, a professor of food science at Cornell University. Lee and Seoul National University colleagues Ki Won Lee, Hyong Joo Lee and Kyung-Sun Kang reported that gap junction intercellular communication inhibition is related to the carcinogenic process, especially tumor growth. Although vitamin C prevents inhibition of GJIC, according to the researchers, quercetin—a bioflavonoid—has an even stronger effect.
Lee and his colleagues see great promise in quercetin and vitamin C's cancer preventative actions, but they promote a varied and balanced diet as the best defense. "We strongly believe that people should take in a variety of fruits and vegetables in their daily diet because one food item, including food supplements, does not supply all the necessary nutrients and phytochemicals [antioxidants]," Lee said.
Barbara Hey is senior editor for Delicious Living.
Natural Foods Merchandiser volume XXIII/number 3/p. 9