| Concern regarding increased cancer risk from exposure to ionizing radiation has resulted in some authorities questioning the wisdom of frequent X-rays and computed tomography (CT) scans. However, in many cases, the benefits of these imaging procedures can outweigh their harm. At the Society of Interventional Radiology's 36th Annual Scientific Meeting held in Chicago this month, Kieran J. Murphy, MD, FSIR reports that a combination of antioxidants consumed prior to medical imaging studies involving ionizing radiation could help protect against their damaging effects. Dr Murphy and his colleagues tested the effects of antioxidants on blood samples drawn from two volunteers. The antioxidant nutrients vitamin C and glutathione were administered to the samples prior to 2 Gy gamma irradiation and DNA damage was assessed. Additional samples were tested with higher concentrations of vitamin C prior to receiving diagnostic doses of ionizing radiation. The subjects then were given vitamin C, glutathione and uric acid orally for five days during which blood was drawn daily and subjected to CT radiation, and DNA injury to white blood cells was evaluated. The researchers observed a reduction in DNA injury in blood samples treated with vitamin C and glutathione compared with control samples. Oral administration of the antioxidants also resulted in a reduction in DNA injury. The trial is the first of its kind to evaluate the protective effect of antioxidants against CT radiation in humans. Dr Murphy, who is deputy chief of radiology at the University of Toronto and University Health Network in Toronto, explained that humans are 70 percent water, and when X-rays collide with water molecules, free radicals are produced. Free radicals react with cellular components, damaging the body's genetic material, which can lead to cancer. "There is currently a great deal of controversy in determining the cancer risks associated with medical imaging exams," Dr Murphy stated. "Although imaging techniques, such as CT scans and mammograms, provide crucial and often life-saving information to doctors and patients, they work by irradiating people with X-rays, and there is some evidence that these can, in the long run, cause cancer." "In our initial small study, we found that pre-administering to patients a proprietary antioxidant formulation resulted in a notable dose-dependent reduction in DNA injury," he reported. "This could play an important role in protecting adults and children who require imaging or a screening study." "Pre-administering this formula before a medical imaging exam may be one of the most important tools to provide radioprotection and especially important for patients getting CT scans," he emphasized. | 
