Zinc status affects DNA damage and oxidative stress in healthy adult men

Abstract

Zinc plays an important role in the maintenance of DNA integrity and antioxidant defense in cells. Our lab has shown in rats that zinc depletion increases DNA damage and perturbs oxidative stress. In the current human dietary intervention study, we aimed to evaluate the effects of zinc depletion and repletion on DNA damage, oxidative stress and antioxidant defenses in humans. Total 9 healthy men with daily zinc intake >11mg/d were recruited. Subjects underwent three consecutive dietary periods: baseline (2 wks, 11mg Zn/d), zinc‐depletion (0.6 mg Zn/d for 1 wk and 4 mg Zn/d for 5 wks), and zinc‐repletion (4 wks, 11 mg Zn/d). DNA damage in peripheral blood cells, plasma oxidative stress and antioxidant defenses were assessed at different time points. Human dietary zinc depletion caused a significant increase in DNA strand breaks in peripheral blood cells (P<0.05), but did not alter lipid peroxidation, as indicated by plasma F2‐isoprostanes. The increased DNA strand breaks were reduced to baseline levels following zinc repletion (P<0.05). Although plasma tocopherol levels significantly increased after zinc depletion, plasma total antioxidant capacity and erythrocyte SOD were not changed. This is first study that demonstrates increases in DNA with human zinc depletion and suggests that zinc may be essential for maintaining DNA integrity in humans. This work is supported by the NCBA (KHB) and USDA 2005‐35200‐15439 (EH).Grant Funding SourceNCBA (KHB) and USDA 2005‐35200‐15439