GENEVA, N.Y. – A team of scientists from Cornell University and Seoul National University of Korea have reported a new mechanism by which vitamin C fights cancer.
“Vitamin C has been considered one of the most important essential nutrients in our diet since the discovery in 1907 that it prevents scurvy,” said C.Y. Lee, food scientist at the New York State Agricultural Experiment Station in Geneva, NY.
“In addition, vitamin C has several important functions in our body for the synthesis of amino acids and collagen, wound healing, metabolism of iron, lipids and cholesterol, and others. In particular, vitamin C is a well known antioxidant that scavenges free radicals.”
Remained unknown. Except for vitamin C’s free-radical scavenging activity against oxidative DNA damage, the mechanism for its inhibitory effects on carcinogenic tumor formation was not known until now. Lee and three Korean colleagues found that vitamin C blocks the carcinogenic effects of hydrogen peroxide on intercellular communication.
“Vitamin C prevents the inhibition of gap-junction intercellular communication, essential for maintaining normal cell growth, induced by hydrogen peroxide,” said Lee. Inhibition of GJIC is strongly related to the carcinogenic process, especially to tumor promotion.
Different theory. Since other free-radical scavengers, such as propylgallate and Trolox did not prevent inhibition of GJIC by hydrogen peroxide, as reported previously, Lee and his coworkers believed that vitamin C’s antitumor activity operated through a mechanism other than by scavenging free radicals.
The report adds that quercetin, a phytochemical found in apples, has stronger anticancer activity than vitamin C.
“The most powerful weapon we have in the fight against cancer is prevention,” concluded Lee. “A diet rich in phytochemicals and vitamin C will reduce the risk of cancer. These phytochemicals and nutrients are most readily available in fresh fruits and vegetables.”
In cancer prevention, the team suggests that inhibiting tumor promotion, a reversible and long-term process, may be a more practical strategy than preventing tumor initiation, an irreversible and short-term process.
