Short‐term low zinc intake alters DNA damage and zinc transporter expression without changing plasma zinc (122.2)

Abstract

Zinc deficiency continues to be a major concern of international nutrition, yet there are still few sensitive and reliable biomarkers for identifying moderate zinc deficiency or monitoring changes in zinc status. Plasma zinc content is used most frequently, but it is influenced by conditions other than zinc intake and, therefore, is not reliable except when zinc intake is very low. In this study, the sensitivity of leukocytic zinc transporter gene expression and genomic integrity were evaluated in a moderate depletion/repletion study. Eighteen healthy men were provided a low zinc (6 mg/day) diet with added phytate for two weeks followed by an adequate zinc (10 mg/day) diet for four weeks. They then consumed an ad libitum diet while taking a 25mg zinc supplement for three weeks. Leukocyte DNA damage increased (p<0.0001) during the depletion phase, as detected by the Comet Assay. ZIP1, ZIP4, and ZnT1 zinc transporter gene expression was evaluated in isolated leukocytes and measured using qPCR. ZnT1 gene expression increased (p=0.02) during the depletion phase, although total plasma and leukocyte zinc levels did not change. These results suggest that a short‐term, low zinc intake alters genomic integrity and zinc transporter expression, but not plasma zinc. These potential biomarkers may be useful to evaluate zinc deficiency and the effectiveness of zinc interventions in conditions where plasma zinc remains unchanged.Grant Funding Source: This study was funded by a grant from HarvestPlus.