Vitamin C, Cancer, Heart Disease,
and Cataracts

In his book Vitamin C and Cancer (1979) twice Nobel prize winner Linus Pauling claimed that high doses of vitamin C may be effective against cancer. Pauling and Scottish surgeon Ewan Cameron conducted a study in which 100 patients with advanced cancer resistant to other therapies were given 10 g of vitamin C per day. (The RDA for vitamin C is 60 mg/day; 100 mg/day for smokers.) Patients given the vitamin C survived four times longer than did 1,000 historical controls who had not received megavitamin treatment.

In How to Feel Better and Live Longer (1986), Pauling stated that megadoses of vitamins “can improve your general health . . . increase your enjoyment of life and can help in controlling heart disease, cancer, and other diseases and in slowing down the process of aging.” Pauling himself reportedly took at least 12,000 mg daily and raised the amount to 40,000 mg if symptoms of a cold appeared. In 1993, after undergoing radiation therapy for prostate cancer, Pauling said that vitamin C had delayed the cancer's onset for twenty years. This was not a testable claim. He died of the disease in August 1994 at the age of 93.

Pauling’s Claims Met with Skepticism

Mainstream nutritionists were more than a little skeptical about Pauling’s claims, and many still are. Studies published by researchers at the Mayo Clinic rejected the contention of Pauling and others that megadoses of vitamin C can treat cancer. The American Cancer Society issued guidelines suggesting that consuming C-rich foods might reduce the risk of certain types of malignancies. But once you have cancer, vitamin C won't help.

New research suggests that cancer patients who take large doses of vitamin C in the hope of a cure might actually make their disease worse by inadvertently protecting their tumors from radiation and chemotherapy. The concern is based on the discovery that cancer cells actually contain large amounts of vitamin C, which appears to protect them from oxygen damage. Many cancer treatments, especially radiation therapy, work by triggering oxygen damage to the genes of cancer cells.

Other sources, however, cite numerous studies that show the benefits of giving high doses of vitamin C to cancer patients. Frequently unmentioned in the ongoing debate between Linus Pauling and the Mayo Clinic is the fact that Pauling's work has already been independently verified by Japanese researchers. Murata and Morishige's high doses of vitamin C (five grams or more per day) extended patients' lives from an average of 43 to 246 days, a change remarkably similar to that reported by Cameron and Pauling.

While the issue has not been resolved (the Japanese study also lacked a placebo control), two articles in the Canadian Medical Association Journal suggest the Mayo research was flawed and the scientists were biased against the use of “alternative” cancer treatments. Some experts suspect the Mayo Clinic, which tried the treatment for only 10 days, abandoned it too soon. Another theory, proposed by U.S. molecular scientist Dr. Mark Levine, is that the Mayo Clinic erred by giving only oral vitamin C, instead of injecting it intravenously. What was widely overlooked at the time was that patients on the Cameron-Pauling protocol were given vitamin C not only orally but also via intravenous injection. Taken orally, much of the vitamin is lost in urine instead of accumulating in the body's tissues.

Protection against Heart Disease and Cataracts

Although the jury is still out on the issue of vitamin C's protective role against cancer, we certainly have nothing to lose, and potentially much to gain, by a diet rich in fruits and vegetables that contain the vitamin, says Elizabeth Ward in an article entitled Vitamin C: still key for immunity, cancer, heart disease, eye health. “Studies suggest that eating foods rich in antioxidant nutrients, including vitamin C, protects against heart disease. Getting at least 220 milligrams of vitamin C a day was more protective against heart disease than 141 milligrams a day or less, according to a recent study from Korea. In a recent Dutch study, researchers found that those with the lowest intakes of C were 30% more likely to suffer a stroke than those with the highest.

“Researchers at Tufts University and Harvard University, who studied nearly 250 women with no history of cataracts, found that those who took vitamin C supplements for at least 10 years were 77% less likely to show the initial signs of cataracts and 83% less likely to have moderate opacities than those who took no supplemental C. It's uncertain how much vitamin C is necessary to saturate eye tissues, but experts estimate it's between 150 and 250 milligrams a day.

“In combination with other nutrients, vitamin C has also shown benefit in slowing the progression of age-related macular degeneration, a condition that damages the retina and can destroy vision.”