genotoxic? Vitamin C spurs chemical production DNA damaging, at least in a test tube.
Vitamin C has long been touted as a healthy and balanced dietary supplement because it can protect against certain types of DNA damage. It also now seems to have an unpleasant chemical side effect. In the June 15 issue of Science , the researchers report that vitamin C may also stimulate the formation of molecules known to scramble the DNA.
Antioxidants such as vitamins C and E can disarm the highly destructive molecules called free radicals, so that many people believed that antioxidant supplements might help prevent cancer. This has not proven to be true in human trials, however. Now researchers led by Ian Blair of the University of Pennsylvania in Philadelphia may have an explanation.
In the process of destruction of free radicals, vitamin C is transformed into what is called a radical vitamin C. When certain metal ions are close to the radical vitamin C can transform compounds called lipid hydroperoxide in genotoxic, which switch bases around the DNA, disrupting its delicate code. However, these metal ions are rare in human blood
Something had to be the formation of genotoxic, although :. Even healthy people showed characteristic DNA damage induced by genotoxic. Blair and his colleagues decided to see if vitamin C alone would do. Working in the solutions thoroughly cleaned of all relevant metal ions, the researchers showed that the equivalent of an additional 0 milligrams of vitamin C could trigger the formation of genotoxic suspects.
It is not known how a great risk this reaction arises, however. Vitamin C concentrations researchers used are not much higher than those found in normal human blood. But not all people have high levels of commodity genotoxic lipid hydroperoxide. Blair and his colleagues plan to look more closely at the two patient populations that are :. Women with breast cancer and children who take certain drugs for leukemia
The prevalence of these genotoxic and DNA damage they cause was Puzzling cancer biologists for years because the relevant metal ions are rare in the blood and the conditions are not quite right. "No one had any idea where they came from," said Larry Marnett, a biochemist at Vanderbilt University in Nashville, Tennessee. The new explanation, that vitamin C could be the trigger, "a lot of chemical sense. "
Center for Cancer Pharmacology at the University of Pennsylvania
website laboratory Blair
Learn more about vitamin C Linus Pauling Institute
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