A New Look at Vitamin C

For 3000 years, sailors, soldiers, and explorers lived in fear of developing scurvy. No one knew the cause or the cure of this often-fatal disease. Then, in 1740, an Englishman, Dr James Lund, showed that citrus fruit could cure scurvy. Fifty years after Lund's discovery, rations for British sailors included one lime per day, earning the British the nickname "limey."

It took almost another 200 years for scientists to discover that the substance in citrus fruits that cured scurvy was vitamin C. Since then, vitamin C has been considered a wonder worker, its powers attributed to many so-called cures, from the common cold to heart disease and cancer. In the 1970s, Nobel prize winner Linus Pauling conducted studies that suggested that large doses of vitamin C cold extend the lives of terminally-ill cancer patients. Pauling's research was subsequently discounted by studies at the Mayo Clinic, which found large doses of vitamin C to be ineffective in treating cancer. And vitamin C in cancer treatment has recently been back in the news because researchers have found that cancer patients who take large doses of it might actually be protecting their tumors from radiation and chemotherapy.

Apparently cancer cells contain large amounts of vitamin C, which appears to protect them from oxygen damage. Many cancer treatments, particularly radiation therapy, work by damaging cancer cells through oxidation. A high level of vitamin C intake could give cancer cells some protection from this oxidizing process, rendering cancer treatments less effective.

Dr. David Golde, physician-in-chief at Memorial Sloan Kettering Cancer Center, is leader of the team that discovered that cancer cells have a high concentration of vitamin C. The team has yet to determine the function of the vitamin C inside cancer cells, but Dr. Golde hypothesizes that "the cancer cell wants vitamin C because it wants the antioxidant protection."

At a meeting of the American Cancer Society in March 2000, Dr. Golde warned cancer patients against taking too much vitamin C. However, although taking big doses of vitamin C supplements is not advised, Dr. Golde says that multivitamins and vitamin-rich foods are safe.