Dietary intake and impact of zinc supplementation on the immune functions in elderly: Nutrigenomic approach

Abstract

Nutrient zinc is a relevant micronutrient involved in maintaining a good integrity of many body homeostatic mechanisms, including immune efficiency, owing to its requirement for the biological activity of many enzymes, proteins, and for cellular proliferation as well as genomic stability. Old people aged 60-65 years and older have zinc intakes below 50 % of the recommended dietary allowances on a given day. Many causes can be involved: among them, impaired intestinal absorption and altered subcellular processes (zinc transporters including Zip and ZnT family, metallothioneins, divalent metal transporter 1) are the most relevant. Zinc supplementation can remodel the immune alterations in elderly leading to healthy ageing. Several zinc trials have been carried out but with contradictory data on immunity, perhaps due to incorrect choice of old subjects who effectively need zinc supplementation. Old subjects with specific metallothioneins and IL-6 polymorphisms are more prone for zinc supplementation. Foods containing zinc (Mediterranean diet) may be enough to restore immunity in other elderly. We report the main causes of low zinc dietary intake in elderly and the impact of zinc supplementation upon the inflammatory/immune response on the basis of individual interleukin-6 and metallothioneins polymorphisms (nutrigenomic approach).