What Effect does Ascorbic Acid have on Cancer?

The results of several trials are conflicting Since the late 1960s several studies, which test the efficacy of ascorbic acid [vitamin C) in inhibiting

malignant tumour growth, have been undertaken. There was some evidence which led to the hypothesis that ascorbic acid could raise the resistance of the host against tumour cells. A further retrospective study substantiated this theory by showing that tumour patients taking ascorbic acid survived longer. A double-blind trial at the Mayo Clinic has since demonstrated that ascorbic acid was no more efficacious than placebo in either halting tumour growth or patient survival time. However, the design of this trial was questioned; prior to the study many patients had received cytotoxic chemotherapy which could have interfered with action of ascorbic acid. In a recent well designed, double-blind study [see Therapy section, this issue, p9] patients with metastatic colorectal carcinoma, who had not previously received cytotoxic therapy, took either oral ascorbic acid 10 g/day or placebo. The results concurred with the findings of the Mayo Clinic trial, namely that ascorbic acid had no effect on advanced tumour disease. Still, at present, results from in vitro studies are promising and if the evidence becomes more substantial further clinical studies should be performed. Wittes. R.E.: New England Journal of Medicine 312: 178-179 (17 Jan 1985)

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