Serious flaws in study on vitamin C treatment in cancer

Mar 5 2009

Serious flaws in a recent study, which concluded that high doses of vitamin C reduce the effectiveness of chemotherapeutic drugs in the treatment of cancer, are revealed in the current issue of Alternative and Complementary Therapies.

This report is available free online at www.liebertpub.com/act

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 antitumor effects of the chemotherapeutic agents.

Challem points out two main problems with the study: the oxidized 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 tumor cell death. In addition, it may promote postsurgical healing by enhancing collagen formation, and increase tissue resistance to tumor spread.

Challem suggests that, "The ideal therapeutic approach would be to tailor individual treatment, including IV vitamin C, from a menu of options."