Science to practice: can antioxidant supplements protect against the possible harmful effects of ionizing radiation from medical imaging?

A novel mixture of antioxidants was shown to reduce formation of double-strand DNA breaks (DSBs), as indicated by phosphorylated histone variant g-H2AX foci, in human lymphocytes following in vitro radiation with a radiation dose equivalent to 10 mGy (1). While provocative, it is too soon to conclude that antioxidant supplements should be used to protect against any future harmful effects of ionizing radiation potentially associated with medical imaging (2). It is unclear whether g-H2AX foci are associated with increased cancer rates, no experimental study has found any protective agent to reduce future cancer rates, and exposures typical of diagnostic imaging examinations are in the range that epidemiologic investigation is unable to detect an increase in cancer rates (even if one exists). Nonetheless, such research is encouraged as medical radiation is the number one source of population exposure in the United States. Patients who undergo frequent medical imaging examinations can accumulate doses that are in the range at which excess cancers have been demonstrated, and any protection afforded by a nontoxic antioxidant compound would be an exciting accomplishment.