In the Medical Journal Watch column of the latest issue, Jack Challem, a personal nutrition coach and nutrition author from Tucson, Arizona, and a regular contributor to the Journal, challenges the findings of a study published in Cancer Research (2008;68:8031-8038), in which the authors conclude that vitamin C given to mice or cultured cells treated with common anti-cancer drugs reduces the anti-tumor effects of the chemotherapeutic agents.
Challem points out two main problems with the study: the oxidised form of vitamin C (dehydroascorbic acid) and not actual vitamin C (ascorbic acid) was used; and in the mouse experiments, the animals were given toxic doses of dehydroascorbic acid, a compound that is not used as a dietary supplement in humans.
"This study and the subsequent headlines [it generated] were a grievous disservice to physicians and patients with cancer," says Challem. He adds that "considerable positive research...has shown striking benefits from high-dose vitamin C (ascorbic acid) in cancer cells and animals-and in actual human beings."
High-dose intravenous vitamin C is a common form of alternative and complementary therapy for patients receiving chemotherapeutic drugs and is believed to help bring about tumour cell death. In addition, it may promote postsurgical healing by enhancing collagen formation, and increase tissue resistance to tumour spread.
Challem suggests that, "The ideal therapeutic approach would be to tailor individual treatment, including IV vitamin C, from a menu of options."
