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| Vitamin C Is Not Effective against Cancer | Aug. 2, 2000 | |
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| Provided by: Special to CANOE | ||
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| Written by: 3 | ||
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| The claim that vitamin C is useful in the treatment of cancer is largely attributable to Linus Pauling, Ph.D., a distinguished chemist who became enamored with vitamins late in his career. In 1976 and 1978, he and a Scottish surgeon, Ewan Cameron, M.B., Ch.B., reported that patients treated with high doses of vitamin C had survived three to four times longer than similar patients who did not receive vitamin C supplements. The study was conducted at a hospital in Scotland where Dr. Cameron treated 100 advanced cancer patients with 10,000 milligrams grams of vitamin C per day. The clinical course of these patients was then compared with that of 1,000 patients of other doctors whose records were obtained from the same hospital, but who had received no vitamin C. The findings were published in 1976 in the Proceeding of the National Academy of Sciences.
The 1976 report emphasized that all of the patients had been "treated initially in a perfectly conventional way, by operation, use of radiotherapy, and administration of hormones or cytotoxic substances." The vitamin C patients were reported to have survived an average of 300 days longer than that of the controls. They were also reported to have shown an improvement in their quality of life. In response to doubts about the study's quality, Cameron and Pauling replaced some of the patients and controls and published another analysis in 1978 in the same journal. In 1979, two Japanese researchers affiliated with the Linus Pauling Institute claimed similar results in two studies totaling 130 cancer patients treated during the 1970s. The Pauling/Cameron study was not a clinical trial in which patients were compared to carefully matched patients chosen at random. Instead, Pauling and Cameron attempted to reconstruct what happened to the control group by examining their medical records. In 1982, William D. DeWys, M.D., chief of the clinical investigations branch of the National Cancer Institute's cancer therapy program, pointed out that the vitamin C and control groups had not been properly matched. First, he observed that no data had been published to demonstrate that the patients had been matched by stage of their disease, functional ability, weight loss, and sites of metastasis, all of which are important judging the stage of the disease. Then he noted that Cameron's patients began getting vitamin C when Cameron judged them "untreatable" and their subsequent survival was compared to that of the control patients from the time they had been labeled "untreatable." DeWys reasoned that if the two groups were comparable, the average time from the initial diagnosis to "untreatable" status should be similar for both groups. But they were not. He concluded that many of Cameron's patients had been labeled untreatable earlier in the course of their disease and would therefore be expected to live longer. DeWys also noted that more than 20% of the patients in the control group had died within a few days of being labeled untreatable, whereas none of Cameron's patients had died. This, too, suggested that Cameron's patients had had less advanced disease when they were labeled untreatable. In the Japanese study, the treatment and control groups were treated with various doses and at different times, which made the conclusions even more questionable. Nevertheless, to test whether Pauling might be correct, the Mayo Clinic conducted three double-blind studies involving a total of 367 patients with advanced cancer. The studies, reported in 1979, 1983, and 1985, found that patients given 10,000 mg of vitamin C daily did no better than those given a placebo. Moreover, high doses of vitamin C can have significant adverse effects. High oral doses can cause diarrhea. High intravenous dosage has been reported to cause kidney failure due to clogging of the kidney tubules by oxalate crystals Given these hard facts, it is foolish for cancer patients to seek treatment with megadoses of vitamin C. |
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