Researchers have found evidence to suggest that vitamin C may dramatically reduce the effectiveness of anti-cancer drugs.
Results of the laboratory study by Dr Mark Heaney and colleagues at the Memorial Sloan-Kettering Cancer Center found that pre-treating cells with vitamin C resulted in a dose-dependent decrease in the cytotoxic properties of the anti-cancer drugs doxorubicin, cisplatin, vincristine, methotrexate, and imatinib. With high doses of vitamin C reducing the efficacy of some of the drugs tested by as much as 70%.
Further investigations revealed that vitamin C appears to prevent anti-cancer drugs from disrupting the electrical potential of the surface membrane of the mitochondria, thus protecting the mitochondria from damage. Many chemotherapy drugs target the mitochondria as mitochondrial damage typically leads to cell death.
The researchers conclude: “These results support the hypothesis that vitamin C supplementation during cancer treatment may detrimentally affect therapeutic response.”
Heaney ML, Garder JR, Karasavas N, Golde DW, Scheinberg DA, Smith EA, O’Connor OA. Vitamin C antagonizes the cytotoxic effects of antineoplastic drugs. Cancer Research. 2008;68:8031-8038.
