Life Extension Magazine August 2010
Protect your DNA from CT Scans and X-rays
By Robert Klein
S-adenosylmethionine (SAMe) is a powerful methyl group donor that’s essential for keeping up cellular levels of the vital antioxidant glutathione.79,80 Enzymes vital for DNA repair (and hence cancer protection) can’t function properly in the absence of methyl donors such as SAMe.81 In early 2010 we learned that ionizing radiation actually suppresses SAMe levels in animal models.82 Increasing the animals’ SAMe levels, on the other hand, minimized DNA damage from ionizing radiation.82
Vitamins and Trace Minerals
The “ACE” vitamins (A, C, and E) offer proven antioxidant protection as a result of their molecular structures. High intakes of these vitamins and other antioxidants protect airline pilots from radiation-induced chromosomal damage,83 an occupational hazard in those who work at high altitudes. In fact, ACE supplements have been proposed as “space foods” to protect astronauts from high radiation levels.84
Beta-carotene, the precursor of vitamin A was first used clinically in the wake of the Chernobyl nuclear accident in treatment of children from the region. Supplementation reduced the amount of radiation-induced oxidized lipids.85 More controlled animal studies showed that vitamin A could reverse radiation-induced gene expression abnormalities that could lead to cancer.86-88 Other studies show that vitamin A ameliorates other radiation effects and enhances death of cancerous cells.89 Still other studies reveal that vitamin A can actually prevent radiation-induced death of healthy cells.90
Vitamin C, together with natural antioxidant systems such as glutathione, helps protect DNA and chromosomes from oxidative damage.91-93 Vitamin C also inhibits radiation-induced death of human blood cells.94 Remarkably, vitamin C can counteract radiation-induced “long-lived radicals” (LLRs) that destabilize chromosomes and induce cancerous mutations.95 The ability to counter both classical radicals and LLRs may be vital in preventing genetic damage from radiation.95
Like vitamin C, vitamin E stabilizes free radicals once they form, reducing their toxicity, an effect vital in radioprotection.7 Importantly, vitamin E enhances the growth-inhibiting effect of radiation on cancer tissue while simultaneously protecting normal cells.96 Animal studies show that vitamin E significantly protects mice from dying after exposure to otherwise lethal levels of gamma rays.97 Intriguingly, this effect is the result of modulation of cytokines; it is accompanied by valuable increases in new blood cell formation suppressed by radiation.97,98
A remarkable study among X-ray technicians reveals just how powerful antioxidant vitamins can be. Radiology techs are nominally protected by elaborate shielding, but they’re still exposed to unnaturally high levels of radiation over the course of a lifetime. As a result they tend to have higher levels of tissue oxidation. But when a group of techs was supplemented with vitamins C (500 mg) and E (150 mg) daily for 15 weeks, their markers of tissue oxidation plummeted, and their levels of natural antioxidants (such as glutathione in red blood cells) rose significantly.99
Our endogenous antioxidant systems such as superoxide dismutase, catalase, and glutathione peroxidase all depend on trace minerals as cofactors for their function. That makes those minerals, especially zinc and manganese, vitally important for sustaining whole-body resistance to ionizing radiation. Zinc supplements protected rats from oxidant damage to their red blood cells induced by radioactive iodine.100,101 And a zinc supplement protected bone marrow, but not tumor cells, from radiation-induced damage.102 Since mitochondria produce huge amounts of free radicals, they are especially susceptible to radiation damage. Both zinc and manganese provide powerful mitochondria-specific radioprotection in animal studies.103
Other Potent Radioprotective Nutrients
As we’ve noted, most nutrients with powerful antioxidant activity can be expected to help protect us against radiation exposure from CT scans.104 In addition to those we’ve discussed, there’s good evidence for radioprotection by spirulina extracts, which protect bone marrow cells from DNA damage.105 Melatonin also protects dividing cells and circulating blood cells from chromosomal injury by radiation.106,107 Licorice extracts block DNA damage and protect lipids from radiation-induced peroxidation.108 The Indian gooseberry (Emblica officianalis) increases survival time and reduces mortality of mice exposed to whole-body radiation.109 Effects include protection against lipid peroxidation and protection of rapidly-dividing cells in the intestine.110 Carnosic acid and other rosemary extracts protect against DNA damage through their antioxidant activity, both before and after radiation exposure.111
Summary and Suggestions
Radiation from “routine” diagnostic studies, especially CT scans, poses a substantial and largely unrecognized threat to our health. But radiation damage primarily stems from free radical formation. That means we can protect ourselves powerfully with antioxidant nutrients. Naturally, you should already be using a comprehensive antioxidant regimen for health maintenance. But should you find yourself (or a loved one) in line for a CT scan, X-ray, or other high-radiation procedures, consider the following suggestions as soon as you learn you’ll undergo the test:
No one wants to take unnecessary risks with their health—ask your doctor if a planned test is truly the only way to get desired diagnostic information. But these steps can offer significant protection in the event that such a study is truly unavoidable.
If you have any questions on the scientific content of this article, please call a Life Extension® Health Advisor at 1-866-864-3027.
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