Zinc in Human Health and Infectious Diseases

Abstract

During the last few decades, the micronutrient zinc has proven to be an important metal ion for a well-functioning immune system, and thus also for a suitable immune defense. Nowadays, it is known that the main cause of zinc deficiency is malnutrition. In particular, vulnerable populations, such as the elderly in Western countries and children in developing countries, are often affected. However, sufficient zinc intake and homeostasis is essential for a healthy life, as it is known that zinc deficiency is associated with a multitude of immune disorders such as metabolic and chronic diseases, as well as infectious diseases such as respiratory infections, malaria, HIV, or tuberculosis. Moreover, the modulation of the proinflammatory immune response and oxidative stress is well described. The anti-inflammatory and antioxidant properties of zinc have been known for a long time, but are not comprehensively researched and understood yet. Therefore, this review highlights the current molecular mechanisms underlying the development of a pro-/ and anti-inflammatory immune response as a result of zinc deficiency and zinc supplementation. Additionally, we emphasize the potential of zinc as a preventive and therapeutic agent, alone or in combination with other strategies, that could ameliorate infectious diseases.

Improving Dietary Zinc Bioavailability Using New Food Fortification Approaches: A Promising Tool to Boost Immunity in the Light of COVID-19

“…Since there is no specialized zinc storage system in the human body, a sufficient daily intake of Zn is required to achieve optimum physiological function [ 5 ]. Zn is involved in the main metabolic pathways, either as a cofactor or as a constituent of the structure of enzymes [ 6 ]. More than 2000 finger proteins, including transcription factors, steroid receptors, hormones, and enzymes, have been shown to rely on Zn for the maintenance of their three-dimensional structures [ 10 ].…”

“…More than 2000 finger proteins, including transcription factors, steroid receptors, hormones, and enzymes, have been shown to rely on Zn for the maintenance of their three-dimensional structures [ 10 ]. In light of these facts, Zn is involved in a broad variety of biological processes, such as cell proliferation and differentiation, the cell cycle, the homeostasis of reactive oxygen species (ROS), and the immunological response [ 6 , 10 ]. Variations in normal Zn concentrations may lead to several fatal illnesses, alterations in immune responses, stunted development, and neurological problems, which have all been linked to Zn deficiency [ 11 ] in addition to increasing susceptibility to environmental pollutant toxicity [ 12 , 13 ].…”

“…Studies have confirmed the essential role of Zn for the human microbiome, as well as the influence of the Zn-induced modulation of the intestinal microflora and the accumulation of metabolites on the immunological regulation of the body’s status [ 36 ]. Zn impacts numerous parts of the immune system, from the skin’s barrier to gene regulation inside cells, and its molecular processes for modulating immunological response during infection have been investigated for decades, as reviewed by [ 6 , 35 ]. Recently, it has been documented that epigenetic mechanisms regulate the expression of various physiological-function-related genes including those of the immune system, modifying the development of the innate and adaptive immune responses [ 37 ].…”

“…Zn deficiency is most common in the elderly, vegetarians, alcoholics, pregnant and lactating women, and people with chronic diseases [ 5 ]. Zn deficiency occurs for several reasons: lack of the element in the diet, insufficient Zn absorption, and increased Zn loss from the body [ 6 , 7 ]. This leads to a number of functional disorders of hormones, the central nervous system, and reduced immunological protection [ 6 , 7 ].…”

“…Zn deficiency occurs for several reasons: lack of the element in the diet, insufficient Zn absorption, and increased Zn loss from the body [ 6 , 7 ]. This leads to a number of functional disorders of hormones, the central nervous system, and reduced immunological protection [ 6 , 7 ]. Excess Zn also leads to acute effects and chronic diseases.…”