Results from a recent study suggest interactions among zinc deficiency, DNA integrity, oxidative stress and DNA repair and suggested a role for zinc in maintaining DNA integrity (J Nutr. 2009;139(9):1626-31). Sprague-Dawley rats were fed zinc-adequate (ZA; 30 mg Zn/kg) or severely zinc-deficient (ZD; less than 1 mg Zn/kg) diets or were pair-fed zinc-adequate diet to match the mean feed intake of ZD rats for three weeks. After zinc depletion, rats were repleted with a ZA diet for 10 days. In addition, zinc-adequate (MZA 30 mg Zn/kg) or marginally zinc-deficient (MZD; 6 mg Zn/kg) diets were given to different groups of rats for six weeks. Severe zinc depletion caused more DNA damage in peripheral blood cells than in the ZA group and this was normalized by zinc repletion. Researchers also detected impairments in DNA repair, such as compromised p53 DNA binding and differential activation of the base excision repair proteins 8-oxoguanine glycosylase and poly ADP ribose polymerase. MZD rats also had more DNA damage and higher plasma F(2)-isoprostane concentrations than MZA rats and had impairments in DNA repair functions. However, plasma antioxidant concentrations and erythrocyte superoxide dismutase (SOD) activity were not affected by zinc depletion.
