Saturday, April 01, 2006

Could Linus Pauling Have Been Right?

Scientists from the National Institutes of Health and McGill University in Canada are re-examining the effectiveness of vitamin C treatment of cancer. There are indications that the problem with some past studies may have been the method of administering the vitamin.

Oral dosing was used in the studies that found no benefit for vitamin C in treating cancer, instead of intravenous dosing, or a combination of the two as Linus Pauling and Dr. Ewan Cameron had done when they reported success with the treatment in the 1970's and 1980's. Pauling has long been considered a quack by the conventional medical community, but that assessment may need revising if these latest findings are confirmed with further research.

Intravenously administered vitamin C as cancer therapy: three cases
Sebastian J. Padayatty et al, CMAJ • March 28, 2006; 174 (7). doi:10.1503/cmaj.050346.
The National Institutes of Health and McGill University

“Larger doses (50–100 g) given intravenously may result in plasma concentrations of about 14 000 µmol/L. At concentrations above 1000 µmol/L, vitamin C is toxic to some cancer cells but not to normal cells in vitro.”

High-dose vitamin C therapy: Renewed hope or false promise?
Sarit Assouline and Wilson H. Miller, CMAJ • March 28, 2006; 174 (7). doi:10.1503/cmaj.060228.
McGill University

“…there is recent evidence from laboratory experiments to support the possibility that high-dose intravenous treatment might be more effective. Chen and associates report that vitamin C levels achievable in vivo only by intravenous infusion are selectively cytotoxic in vitro to various cancer cell lines but not to normal cells by a mechanism involving formation of hydrogen peroxide.9This is consistent with a growing literature that reactive oxygen species play an important role in the mechanism of action of proven cancer treatments and that impaired oxidation-reduction balance in cancer cells might cause induced reactive oxygen species to selectively kill cancer cells.10–12 Indeed, additional mechanistic studies may help define tumour types more likely to respond to this and other strategies that induce reactive oxygen species.

There is, therefore, both ample interest and evidence to support research of high-dose vitamin C administered intravenously as a treatment for cancer. At our institution, we have taken the next step of conducting a phase I trial to establish the safety and dosage of high-dose intravenous vitamin C therapy for patients with advanced cancer; we are collecting preliminary efficacy, quality-of-life and pharmacokinetic data.”

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