Genetic polymorphisms and zinc status: Implications for supplementation in metabolic diseases

Background: Zinc is an essential component for all living organisms, representing the second most abundant trace element, after iron. This element is widely distributed in the tissues of a human body where it is involved in normal growth, reproduction and several biological functions including immunity, energy metabolism and antioxidant processes. Because of its essential role, zinc levels in the human body must remain constant, independently of dietary intake fluctuations. The homeostasis of zinc is a well-regulated cellular process and has been reported to be chiefly mediated by the expression and activity of zinc-binding proteins such as metallothioneins and zinc transporters. Genes encoding for these proteins are subjected to genetic variants.Conclusion: New studies are needed to clarify the interaction between individual genetic profile and zinc status. Moreover, there is a need for a better interaction between the scientific bodies and health professionals to allow better dietary and behavioural recommendations to promote human health, with particular concern to elderly people. Methods: We performed a multi-database electronic search to provide an overview on the relationship between specific polymorphisms (SNP) of genes encoding for metallothioneins and zinc transporters and their relationship with zinc status, immune function and some non-communicable diseases. Results: A number of SNP are implicated in a range of metabolic disease. Some SNP may affect the impact of zinc supplementation on immune function, diabetes, and obesity. Conclusion: New studies are needed to clarify the interaction between individual genetic profile and zinc status. Moreover, there is a need for a better interaction between the scientific bodies and health professionals to allow better dietary and behavioural recommendations to promote human health, with particular concern to elderly people.