A shocking new study reveals that there may be a new tool in the battle against cancer, and it’s surprisingly common. According to a report from Science Magazine, researchers have found that vitamin C can in fact kill tumor cells in mice that carry a deadly mutation, confirming decades of speculation about the benefits of vitamin C.

The study, published in the journal Science, shows that high doses of vitamin C can slow the growth of tumors in mice with a common mutation that leads to the spread of cancer throughout the body. Scientists have yet to test the effects on humans, but they are hopeful that the findings could open the door to a wide range of new treatments for several types of cancerous growths.

According to Channing Der, a molecular biologist at the University of North Carolina Chapel Hill, the study could open the door for more robust research into the cancer-treating benefits of vitamin C. Vitamin C researcher Mark Levine from the National Institute of Diabetes and Digestive and Kidney Diseases agrees, hoping that more people will begin to pay attention to recent studies on the benefits of ascorbic acid.

Treating cancer with vitamin C first arose as a viable idea in 1971 when Nobel Prize-winning chemist Linus Pauling and a Scottish colleague reported successfully treating cancer patients with vitamin C pills. After two clinical trials failed, however, people stopped believing in the viability of vitamin C as an effective treatment for cancer cells.

Levine’s studies suggested that instead of administering vitamin C in pill form, intravenous vitamin C treatment at high doses is what it took to destroy cancerous cells. Despite recent small trials that suggested vitamin C could work in conjunction with chemotherapy to extend cancer survival, a cloud of doubt loomed over Levine and other researchers.

It wasn’t until Jihye Yun, a graduate student at Johns Hopkins University, discovered that colon cancer cells carrying a mutation in the genes KRAS or BRAF produced large amounts of a certain protein that transports glucose through the cell membrane, that vitamin C treatment seemed viable once again. The glucose transporter in the cells, GLUT1, was found to also carry the oxidized form of vitamin C, or dehydroascorbic acid into the cell. This was extremely effective at stopping the cancer cell from producing a chemical that consumes free radicals. By flooding the cancer cells with DHA, they became vulnerable and easier to kill.

According to Lewis Cantley, a researcher at Weill Cornell Medicine in New York City, large doses of vitamin C were found to kill cultured cancer cells with the BRAF and KRAS mutations. The vitamin C raised the overall level of free radicals inside the cell, shutting down an enzyme that was needed to metabolize glucose. This deprived the mutated colon cancer cells of energy, leading to their demise. The doses of vitamin C were extremely high – roughly the same as eating 300 oranges.

The researchers are looking to begin clinical trials that will target cancer patients with KRAS or BRAF mutations. High doses of vitamin C are safe, but doubters fear that the results will not be replicable in humans. Treatment would need to occur every few days over the course of a few months, but Cantley hopes that one day a pill form capable of delivering a high enough dose will be available.

A press release from the University of Toronto outlining the details of the study can be found here.