Thursday, May 14, 2009 by: Henri Junttila
(NaturalNews) 30 years ago the famous Nobel laureate Linus Pauling said that vitamin C supplements can prevent cancer, a highly controversial statement at the time. Now a team of Johns Hopkins scientists have shown that vitamin C stops the growth of some tumors in mice.
The study was lead by Chi Dang, M.D., Ph.D., professor of medicine and oncology and Johns Hopkins Family Professor in Oncology Research. Their work is detailed in Cancer Cell, Volume 12, Issue 3, 230-238, 11 September, 2007. They found that the antioxidants' actual role may be to destabilize a tumor's ability to grow under conditions where there isn't enough oxygen to feed it. The conventional belief is that vitamin C helps prevent cancer growth by grabbing up volatile oxygen free radical molecules and preventing the damage they do to our DNA. "The potential anticancer benefits of antioxidants have been the driving force for many clinical and preclinical studies," Says Dang. "By uncovering the mechanism behind antioxidants, we are now better suited to maximize their therapeutic use."
The researchers caution that while vitamin C is crucial to our health, you should not rush out and buy antioxidant supplements in bulk just to prevent cancer. This study is only preliminary and more research will be needed. The researchers discovered the antioxidant mechanism while looking at mice that had been implanted with human lymphoma (blood cancer) or human liver cancer cells. Both cancers produce high levels of free radicals; they found that they could suppress the free radicals by feeding the mice supplements of vitamin C or N- acetylcysteine (NAC), both powerful antioxidants.
When the researchers examined the cancer cells from the diseased mice not fed the antioxidants, they noticed that their DNA had not been significantly damaged. "Clearly, if DNA damage was not in play as a cause of the cancer, then whatever the antioxidants were doing to help was also not related to DNA damage," says Ping Gao, Ph.D. This discovery led Gao and Dang to suspect that other factors were involved, such as a protein called HIF-1 (hypoxia-induced factor). They found that this protein disappeared in mice that received vitamin C treatment; it is usually abundant in untreated cancer cells. "When a cell lacks oxygen, HIF-1 helps it compensate," explains Dang. "HIF-1 helps an oxygen-starved cell convert sugar to energy without using oxygen and also initiates the construction of new blood vessels to bring in a fresh oxygen supply."
Fast growing tumors can consume enough energy to effortlessly suck the available oxygen from everything that is close to them, thus making HIF-1 crucial for survival. HIF-1 can only function normally if it has fuel to keep it going; it needs free radicals. The researchers found that antioxidants remove the free radicals, thus stopping HIF-1, and the tumor. They confirmed the importance of the hypoxia protein by creating cancer cells with a variant of HIF-1 that did not require free radicals to function. In these cells antioxidants had zero effect on the cancer.
Vitamin C Sources
There are many natural sources of vitamin C, fruits and vegetables are the main foods. Getting your vitamins from natural organic foods is always better than getting them from supplements. Here is a brief list of the fruits and vegetables highest in vitamin C.
And the vegetables: