Dietary zinc restriction and repletion affects DNA integrity in healthy men

Abstract

Background: Zinc plays an important role in antioxidant defense and the maintenance of cellular DNA integrity. However, no experimental human studies have been performed to examine the role of zinc status on DNA damage. Objective: We evaluated the effects of dietary zinc depletion and repletion on DNA strand breaks, oxidative stress, and antioxidant defenses in healthy men. Design: Nine healthy men with reported mean daily zinc intakes .11 mg/d were recruited. Subjects completed 3 consecutive dietary periods: baseline (days 1 to 13; 11 mg Zn/d), zinc depletion (days 14 to 55; 0.6 mg Zn/d for 1 wk and 4 mg Zn/d for 5 wk), and zinc repletion (days 56 to 83; 11 mg Zn/d for 4 wk with 20 mg supplemental Zn for first 7 d). Blood samples were collected on days 1, 13, 35, 55, and 83. DNA damage in peripheral blood cells, plasma oxidative stress, and antioxidant defense biomarkers were assessed. Results: Dietary zinc depletion (6 wk) was associated with increased DNA strand breaks in peripheral blood cells (day 13 compared with day 55; P , 0.05), changes that were ameliorated by zinc repletion (day 55 compared with day 83; P , 0.05). Plasma zinc concentrations were negatively correlated with DNA strand breaks (r = 20.60, P = 0.006) during the zinc-depletion period. Plasma a-and c-tocopherol concentrations, plasma total antioxidant capacity, and erythrocyte superoxide dismutase activity did not change significantly, and plasma F 2 -isoprostanes were unaffected by dietary period. Conclusions: Changes in dietary zinc intake affected DNA singlestrand breaks. Zinc appears to be a critical factor for maintaining DNA integrity in humans.

Zinc deficiency or excess within the physiological range increases genome instability and cytotoxicity, respectively, in human oral keratinocyte cells

“…In contrast, micronuclei and nucleoplasmic bridges may occur due to mis-repair of DNA strand breaks which leads to the formation of acentric chromosome fragments and dicentric chromosomes (Fenech 2007). An increase in DNA strand breaks was found in Zn-depleted cells, which is consistent with previous studies (Ho and Ames 2002;Ho et al 2003;Yan et al 2008;Song et al 2009a;Song et al 2009b;Song et al 2009c;Sharif et al 2011). Higher concentrations of Zn further reduced DNA strand breaks (4 and 16 lM), but at the highest concentration tested (32 lM), an increase in DNA strand breaks was observed suggesting a potential genotoxic effect for both Zn compounds when present in excess; however, this increase may have also been affected by a contribution of damaged DNA in necrotic cells which tended to increase at 32 lM Zn.…”

“…Extensive research has been undertaken to investigate the effect of zinc deficiency on DNA damage events in both in vitro and in vivo systems (Ho and Ames 2002;Ho et al 2003;Song et al 2009a;Song et al 2009b;Song et al 2009c;Yan et al 2008). However, little is known on the effect of zinc concentration on epithelial cells within the buccal mucosa.…”

Telómeros Y Calidad De La Dieta: Una Revision Sistematica

“…En los seres humanos se ha demostrado que la deficiencia de zinc en la dieta causa daño en el ADN (120). En los sujetos mayores, el porcentaje de células con telómeros críticamente cortos y la disminución de la longitud de los telómeros se asocian con disminución de la concentración de zinc lábil intracelular y la proteína de unión al zinc metalotioneina en células mononucleares de sangre periférica (121).…”

Essential Role of Vitamin C and Zinc in Child Immunity and Health

“…41 -43 It is even estimated that a considerable proportion of the Western population is at risk of marginal zinc deficiency. 41,43 Zinc deficiency increases the risk and severity of a variety of infections, restricts physical growth, results in hypogonadism in male adolescents, causes delayed wound healing, affects specific outcomes of pregnancy and may increase the risk of some chronic diseases, including cancer. 26,31,36,41,44,45 This link is attributed to the role of zinc in antioxidant defence and DNA damage repair.…”