vitamin-c-350x122Decades ago, Nobel Prize-winning scientist Dr. Linus Pauling discovered that vitamin C can be effective in treating cancer and other life-threatening illnesses. Because vitamin C is such a simple and safe approach, the conventional medical establishment has been slow to accept Pauling’s work, and the work of other like-minded physicians. Now a new study offers yet more evidence that vitamin C does indeed have cancer-fighting properties. This study shows the powerful antioxidant may be effective in treating a particular class of malignant tumors, including colorectal cancer cells.

The study was published in the journal Science. Researchers from Harvard Medical School, Weill Cornell Medicine, The Sidney Kimmel Comprehensive Cancer Center, Cold Spring Harbor Laboratory and Tufts Medical Center joined forces to assess the effect of high doses of vitamin C on colorectal tumor formation. Employing approximately as much vitamin C as is found in 300 oranges, the researchers documented impaired development of KRAS-mutant and BRAF-mutant colorectal tumors in cultured cells as well as in mice.

The operating theory is that vitamin C protects cells because it is such an effective antioxidant. This study, however, showed the vitamin actually induces oxidation in cancer cells. Inside arteries, which are an oxygen-rich environments, a portion of vitamin C is oxidized and changed into a new compound, dehydroascorbic acid, or DHA. DHA then acts as a “Trojan horse” and permeates the cancer cell membrane, with the assistance of a protein glucose transmitter.

When the DHA has penetrated the cancer cell, the cell’s natural antioxidants try to convert the DHA back into ascorbic acid. Because they cannot be successful, they instead become depleted and die of oxidative stress. Colorectal cancer cells produce larger amounts of reactive oxygen than other cells, so they require more antioxidants to survive. Thus they are more susceptible to the action of the DHA than most types of cancer cells.

Human clinical trials are still pending, but researchers think these preclinical findings indicate promise for a new treatment strategy for colorectal cancer. They also hold out hope that vitamin C may be effective in renal cell carcinoma, bladder cancer and pancreatic cancer. If scientists are able to develop biomarkers, these could help doctors to determine treatment protocols in these cancers.