Antioxidants to Protect Against Radiation

Using Antioxidants to Protect Against Radiation from Medical Imaging.

CT scans, mammograms, X-rays, and PET scans are all common forms of imaging that expose the patient to radiation. This exposure is a common concern as it can increase the risk of cancer, primarily by damaging DNA through the generation of free radicals and hydrogen peroxide. The risk increases with greater radiation exposure and is significantly higher in certain populations such as children and people with a hereditary BRCA mutation. The radiation exposure from medical imaging is necessary in most cases, but should not be overlooked, particularly in people who need to receive regular scans for diagnostic purposes or to monitor diseases such as cancer.

The carcinogenic risk from medical imaging is traditionally mitigated by external factors such as shielding, using the lowest possible radiation dose, and only performing scans when necessary. Unfortunately, there is less discussion around internal factors that may minimize DNA damage such as oral antioxidants to scavenge free radicals. This approach has many advantages including its low cost, ease of administration, and safety.

Several antioxidants can be considered for reducing the free radicals generated by medical imaging, including N-acetyl cysteine (NAC), vitamin C, vitamin E, carotenoids, glutathione, and alpha-lipoic acid. Ideally, the antioxidants are administered to achieve peak blood concentrations at the time of the radiation exposure. This can be estimated by looking at the pharmacokinetics of the antioxidant – the profile of how it is absorbed, metabolized, and excreted from the body. Many antioxidants like NAC, vitamin C, and melatonin are absorbed and excreted rapidly, which allows for dosing shortly before the radiation exposure. Others like glutathione and lycopene can take days of build to peak concentrations.

The use of antioxidants to protect against radiation exposure from medical imaging should be individualized. Which antioxidant, its dose, and the timing of administration may differ based on each person’s medical history, concurrent medications, and health goals. For example, vitamin E needs to be used cautiously in people on blood thinners or at risk of bleeding events. NAC may also be useful for other goals such as preventing radiocontrast-induced kidney and nerve toxicity.

Further research is needed to confirm a reduction in DNA damage following medical imaging with oral antioxidant use, but preliminary studies are promising, and for many this approach could be considered after a discussion with their physician.

If you have questions contact the clinic via our website at or 604-888-8325

Dr. Sarah Soles, ND