Zinc is an ion that contributes to and supports many vital mechanisms of our body. Zinc is required in the formation of zinc finger proteins which are necessary for DNA replication factors. It is involved in the structure of signalling proteins that are important in T cell activation and T-B cell interaction. Zinc deficiency may lead to suppression of immune response, lymphopenia, decrease in the number of circulating T and B cells, and impairment in neutrophil, monocyte and macrophage migration. The normal function of T cells decreases and the destruction of B cells increases. It causes a decrease in the cytotoxicity of natural killer cells (NK) cells and impaired phagocytosis of granulocytes.
In zinc deficiency, the level of thymulin decreases and changes in the levels of immune system chemicals are observed. While cytokine levels of chemicals affecting lymphocytes decrease, inflammatory cytokine levels increase. Long-term zinc deficiency leads to shrinkage in the thymus gland, T cell deficiency in the spleen and lymph nodes, and a decrease in mature B cells in the bone marrow. However, all these negative effects on the immune system can be reversed with zinc therapy.
Low zinc bioavailability in the elderly reduces resistance to infections. After zinc is brought to physiological levels with supportive treatment, it has been observed that infections decrease and life expectancy increases. Zinc deficiency is a common condition in developing countries and is characterised by a decrease in immunity and an increase in infections. It was observed that acute lower respiratory tract infections decreased when zinc was supplemented.
Symptomatic treatment is often sufficient in the treatment of influenza. It is suggested that zinc acts on viruses by disrupting the structure of viral envelope proteins and protecting the membrane structure of epithelial cells.
The use of zinc was evaluated with randomised, double-blind placebo-controlled studies with people given zinc for at least 5 days for colds and at least 5 months for prevention in the Cochrane systematic study in 2011. A significant reduction in the duration of illness was found in 13 studies (966 patients) who received zinc for treatment. On the 7th day of the disease, there was a significant difference between the zinc-treated patient group and the control group. Another important finding of this study is that when zinc is given to healthy individuals with colds in the first 24 hours, it has been found to reduce the severity and duration of the disease. When zinc is given to healthy people for protection for at least 5 months, it has been found that it reduces the rate of colds and antibiotic use.
In placebo-controlled studies, it has been observed that zinc taken in the acute period reduces the duration and severity of the disease and increases the success of treatment. Nutritionists and physicians should consider zinc supplementation during treatment. Numerous studies have shown that zinc supplementation reduces the frequency of pneumonia.
Increasing the intracellular zinc concentration can effectively disrupt the replication of various RNA viruses, including poliovirus and influenza virus. A 2010 study showed that the combination of zinc and PT (pyrithione ionophores) inhibited the replication of "SARS-coronavirus (SARS-CoV), which was isolated at that time" in cell culture.
In 2010, in a meta-analysis of 10 randomised controlled trials involving 50,000 children, one group received a total dose of at least 70 mg zinc daily or weekly for 3 months, while another group received placebo. As a result of this study, lower respiratory tract infection was observed less in the group given zinc. In this study, frequent breathing and abnormal lung sounds and at least one other finding (chest tightness, nasal tightness, fever, cyanosis, lethargy, convulsions) were taken into consideration when the diagnosis of lower respiratory tract infection was made by the physician and zinc reduced lower respiratory tract infection by approximately 35%.
There are also some studies on the efficacy of zinc in the prevention and treatment of bronchopneumonia. In a placebo-controlled study by Brooks WA et al. involving 270 cases aged 2-23 months, 20 mg zinc was given daily in addition to antibiotics. As a result of the study, the severity of the disease and the duration of hospitalisation decreased in the group given zinc compared to the control group. Eliminating zinc deficiency will provide protection against lower respiratory tract infections as well as many diseases.
REFERENCES
- Zinc and Sepsis Wiebke Alker Nutrients 2018, 10, 976 1-17
- Zinc Status and Autoimmunity: A Systematic Review and Meta-Analysis Alessandro Sanna Nutrients 2018, 10, 68
- Zn2+ Inhibits Coronavirus and Arterivirus RNA Polymerase Activity In Vitro and Zinc Ionophores Block the Replication of These Viruses in Cell Culture Aartjan J. PLoS Pathogens | www.plospathogens.org 1 November 2010 | Volume 6 | Issue 11 | e1001176
- Zinc supplementation for pediatric pneumonia Teeranai Sakulchit Vol 63: october • octobre 2017 | Canadian Family Physician 763-765