A new research indicates that vitamin C might have cancer-fighting properties, but at very high doses, possible only through injection into the bloodstream.
The study, by researchers from the National Institutes of Health in Bethesda, Maryland, studied the action of vitamin C as ascorbate on cultures of nine cancer and four normal cells. They found that ascorbate increased the production of hydrogen peroxide that in turn killed cancer cells while leaving normal cells safe. If found effective, the vitamin can revolutionize cancer treatment and eliminate damage to healthy cells that are also affected when a patient undergoes chemotherapy.
The findings, however, don't hold true for high oral doses of vitamin C, as many previous studies have discounted any cancer-fighting benefits of the vitamin.
“These findings give plausibility to intravenous ascorbic acid in cancer treatment, and have unexpected implications for treatment of infections where hydrogen peroxide may be beneficial,” the researchers said in a report published in the
Proceedings of the National Academy of Sciences. “Because intravenous ascorbate is easily available to people who seek it, a phase 1 safety trial in patients with advanced cancer is justified and underway,” the report added.
Mark Levine, the lead author of the study, said that further tests, especially on animals and humans, are required to take these findings seriously.
“If it were to work, even in a couple of cancers, that would be wonderful for patients. So the message is that there may be new hope coming, but it's certainly not here. What this does is provide plausibility that we should be reinvestigating ascorbic acid in cancer treatment. It's not ready for patients. Patients shouldn't get the wrong idea. We don't want to provide false hope,” Levine asserted.
He added that a 10-gm dose of vitamin C administered intravenously showed blood concentrations 25 times higher than the concentration produced by the same dose taken orally. “At the highest concentration of ascorbic acid, if given intravenously, they don't touch normal cells and they kill lots of cancer cells. We don't know why,” he said, adding, “You don't want hydrogen peroxide in the blood itself. But if hydrogen peroxide is present outside the blood, there is the potential that it could work as a drug.”
Oral vitamin C is ejected by the blood's regulatory mechanism if it is in excess. But Levine said that intravenous vitamin C manages to bypass such regulatory action. “I realized that concentrations given intravenously at higher doses could be much higher than could ever be achieved by mouth. This is not nutrition use of ascorbic acid. This is potential use of ascorbic acid as a drug, and it must be said, it's not ready for prime time,” he said.
However, the researcher recommended consuming adequate amounts of vitamin C through fruits and vegetables. “Independent of this work, our recommendations are to consume vitamin C through foods and eat at least five varied fruits and vegetables a day,” he said.
