The Controversy Over Vitamin C and Cancer

A recent study – in cells and mice – was published in the journal Cancer Research and immediately followed by newspaper and internet headlines screaming that vitamin C interfered with the cancer-killing effect of several chemotherapeutic drugs.

The finding contradicted several promising studies – in cells, animals, and people – showing that large amounts of vitamin C enhance the body’s ability to fight cancer. What gives?

The study, conducted by researchers at the Memorial Sloan-Kettering Cancer Center in New York City, used an awful methodology. That’s what gives. I’ll explain.

Most of the vitamin C found in foods and supplements is chemically known as ascorbic acid. The Sloan-Kettering researchers did not use this type of vitamin C. Instead, they used dehydroascorbic acid, which is the “oxidized” form of the vitamin, and found that it reduced the effectiveness of chemo drugs on cells. Meanwhile, in the mouse study, the researchers used dehydroascorbic acid in doses known to be toxic.

No one in the entire world sells dehydoascorbic acid supplements. In fact, when dehydroascorbic acid is formed in the body, it is quickly broken down because of its inherent toxicity. It makes absolutely no sense to (1) call dehydroascorbic acid vitamin C or (2) to use it in cancer experiments.

Several studies have successfully used large amounts of real vitamin C to destroy cancer cells in cell experiments, animals, and people. The current theory is that large amounts of vitamin C – large intravenous doses of vitamin C in people – generate hydrogen peroxide, which functions as a natural chemotherapeutic agent but does not harm normal cells.