Zinc and COVID-19
The trace element Zinc has an anti-inflammatory effect, it can be helpful to optimize the immune function and it reduces the risk of infection. Zinc supplementation can therefore also be a useful strategy to reduce the global burden of SARS-CoV-2 infection in the elderly.
(Source: de Almeida Brasiel PG: The key role of zinc in elderly immunity: A possible approach in the COVID-19 crisis. Clin Nutr ESPEN. 2020 Aug; 38: 65-66)
The role of zinc in antiviral immunity
Zinc is an essential trace element that is important for growth, development and the maintenance of immune function.
It affects all organs and cell types, is an integral part of around 10% of the human proteome and comprises hundreds of key enzymes and transcription factors.
Zinc deficiency is strikingly common, affecting up to a quarter of the population in developing countries, but also various population groups in the developed world, as a result of lifestyle, age and disease-related factors.
As a result, zinc status is a critical factor influencing antiviral immunity, especially since zinc deficient populations are often at high risk for viral infections such as HIV or hepatitis C.
Zinc has a direct antiviral effect and also stimulates innate immunity. Over the past 50 years, a wealth of evidence has accumulated that documents the antiviral effectiveness of zinc against a wide variety of viruses and via numerous mechanisms.
The therapeutic benefits of zinc in viral infections such as the herpes simplex virus and colds result from this.
(Source: Read SA, Obeid S, Ahlenstiel C et al .: The role of zinc in antiviral immunity. Adv Nutr. 2019 Jul 1; 10 (4): 696-710)
Zinc and CoV infections
Chinese scientists expressly point out how immensely important the immune response is in controlling CoV infections and eliminating the viruses. Opposing defense reactions can lead to disorders of the immune system and impaired gas exchange in the lungs. By better understanding the interaction between coronaviruses and the innate immune system, one can hopefully soon reduce the risk of pneumonia caused by CoV.
(Source: Li G, Fan Y, Lai Y et al .: Coronavirus infections and immune responses. J Med Virol, 92 (4), 424-432, Apr 2020)
The trace element zinc is among others necessary for the correct functioning of the immune system. A zinc deficiency leads to rapid and pronounced thymus atrophy, lymphopenia and reduced primary and secondary antibody reactions.
(Source: Rabinovich D, Smadi Y: Zinc.StatPearls (Internet), Treasure Island (FL): Stat Pearls Publishing; 2020 Jan. Last Update Feb. 18, 2020)
Zinc: important for innate immunity and protection against pathogens
The essential trace element zinc plays an important role in the defense against pathogens. Zinc-deficient diets lead to impaired immunity, delayed recovery and a worse course of infection diseases.
Persistent inadequate zinc intake causes dysregulation of the innate immune response and increases the susceptibility to infections, while zinc supplementation can restore the immune system in risk populations and reduce pathogen-related morbidity and mortality.
In the case of infections, a zinc deficit increases the symptoms, which can lead to excessive inflammation and additional tissue damage. In addition to other immune cells, zinc influences the function of macrophages in particular. A zinc deficiency has a negative effect on phagocytosis, the intracellular destruction of pathogens and cytokine production.
Source: Shimizo Y: Gut microbiota in common elderly diseases affecting activities of daily living. World J Gastroenterol. Nov 14, 2018; 24 (42): 4750-4758)
Zinc increases the number of T cells
Zinc is essential for regulating the immune response. T-cell function decreases with age. In a randomized, double-blind, placebo-controlled study of 53 nursing home residents aged 65 or over, 58% had low serum zinc levels. These 31 people received either 30 mg zinc (n = 16) or a placebo (n = 15) daily for a period of 3 months. Zinc supplementation was found to be effective in increasing serum zinc levels, although not all seniors with deficient zinc levels achieved adequate levels. The increase in serum zinc levels was associated with an increase in T-cell function, mainly because the number of T-cells increased.
(Source: Barnett JB et al., Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly: a randomized, double-blind, placebo-controlled trial. Am J Clin Nutr. 2016 Jan 27. pii: ajcn115188)
The role of zinc in the immune system and its cancer defense mechanisms
The human body cannot store zinc reserves, which means that a deficiency can arise relatively quick, especially due to poor nutrition. Severe zinc deficiency is rare, but minor deficiencies are common around the world. Many epidemiological studies suggest a relationship between dietary zinc content and cancer risk.
Zinc’s anti-tumor effects are most commonly associated with its antioxidant properties. However, the influence of zinc on the immune system, on transcription factors, cell differentiation and proliferation, DNA and RNA synthesis and repair, enzyme activation or inhibition, regulation of cellular signaling pathways and the stabilization of cell structure and membranes also play a role.
(Source: Skrajnowska D, Bobrowska-Korczak B: Role of zinc in immune system and anti-cancer defense. Nutrients. 2019 Sep 22; 11 (10))
Zinc has a favorable effect on cardiometabolic risk factors
The effects of zinc on cardiometabolic risk factors were examined in an Iranian systematic review article and meta-analysis of 20 randomized, controlled studies with a total of 1141 participants.
The meta-analysis shows that zinc supplementation significantly reduced the plasma concentrations of triglycerides, VLDL (very-low-density lipoprotein) and total cholesterol.
Zinc also significantly decreased the fasting blood sugar and HbA1c values. Zinc supplements therefore had beneficial effects on glycemic parameters and the lipid profile. Therefore, zinc supplementation appears to be associated with a reduction in cardiometabolic risk factors, which contribute to a reduced risk of atherosclerosis.
(Source: Khazdouz M, Djalalinia S, Sarrafi Zadeh S et. Al. Effects of zinc supplementation on cardiometabolic risk factors: A systematic review and meta-analysis of randomized controlled trials. Biol Trace Elem Res. 2020 Jun; 195 (2): 373-398)
Zinc and warts
In a Turkish study with 49 patients suffering from Verruca vulgaris (average age 32 plus/minus 14 years, 22 men and 27 women) and 40 healthy volunteers, the zinc concentrations with Verruca vulgaris were significantly lower in volunteers than in Healthy. In the patient group, the malondialdehyde (MDA) levels and the HDL values were also significantly higher than in the control group.
The first indicates increased lipid oxidation by free radicals.
The researchers conclude that reduced serum-zinc-levels and increased oxidative stress could be responsible for the development of warts. Zinc is known to have an antioxidant effect.
(Source: Korkmaz S, Sirin FB, Erturan I et al .: Coenzyme Q10, zinc and MDA levels in verruca vulgaris. Turk J Med Sci. DOI: 10.3906 / sag-1909-12. 2020 Jan 30)
Zinc and inflammatory skin diseases
Zinc is used in patients with acne vulgaris for its anti-inflammatory effects. A systematic review that included 22 studies showed that zinc supplementation was beneficial in 10 of 14 studies in acne vulgaris, in one of 2 studies in atopic dermatitis, in one in 1 study in diaper rash and in three of 3 studies in hidradenitis suppurativa (acne inversa).
(Source: Dhaliwal S, Nguyen M, Sivamani RK et al.: Effects of zinc supplementation on inflammatory skin diseases: A systematic review of the clinical evidence. Am J Clin Dermatol. DOI: 10.1007 / s40257-019-00484-0. 2019 Nov 19)
Zinc improves blood glucose profile in gestational diabetes
A Chinese systematic review and meta-analysis of 5 randomized, placebo-controlled studies with a total of 263 patients suffering from gestational diabetes showed that zinc supplementation is effective in reducing fasting blood sugar, insulin and HOMA IR Values and the QUICKI (quantitative insulin sensitivity check index).
(Source: Li X: The influence of zinc supplementation on metabolic status in gestational diabetes: A meta-analysis of randomized controlled studies. J Matern Fetal Neonatal Med. 2019 Aug 22: 1-171)
Incidentally, the German Nutrition Society (DGE) expressly points out that phytate binds zinc in the gastrointestinal tract so that it can no longer be absorbed by the body, i.e. its bioavailability is reduced.
Phytate is a chemical form (anion) of phytic acid. In plants, this serves as a storage form for phosphorus and binds various minerals that the plant needs for germination.
Therefore, it occurs mainly in foods that can also serve as seeds, e.g. in legumes and whole grains.
In addition to the amount of zinc contained in food, the phytate content is the most important factor influencing the absorption of zinc into the human body. In the case of very high phytate levels in the diet, zinc absorption in the intestine can be reduced by up to 45% compared to average phytate levels. Therefore, with a high phytate intake, the intake of zinc must also be increased.
(Source: https://www.dge.de/wissenschaft/weiter-publikationen/faqs/zink/#c8173, accessed on August 28, 2019)
The role of zinc in the endocrine system
The effects of zinc are numerous.
The essential trace element plays a substantial role in maintaining cell membrane integrity, protein-carbohydrate-lipid metabolism, wound healing, growth, development and hormone metabolism.
Growth disorders, hypogonadism and some endocrine diseases are associated with a zinc deficiency.
Zinc increases the synthesis of growth hormones and their number of receptors. There is a lot of zinc in the pancreatic tissue. The trace element is important for regulating the action of insulin and the thyroid hormone metabolism,
i.e. for hormone synthesis, receptor activity, the conversion of T4 to T3 and for the production of carrier proteins.
Low zinc and high leptin levels in obese individuals indicate an essential relationship between zinc and leptin.
Zinc is also linked to the enzyme activity of melatonin synthesis. Melatonin has a regulatory effect on zinc absorption in the gastrointestinal tract.
Furthermore, zinc partially affects the conversion of testosterone to dihydrotestosterone, because the 5α-reductase involved in this conversion is a zinc-dependent enzyme.
(Source: Baltaci AK, Mogulkoc R, Baltaci SB: Review: The role of zinc in the endocrine system. Pak J Pharm Sci. 2019 Jan; 32 (1): 231-239)
Association between zinc deficiency and iron deficiency anemia
Iron deficiency anemia is the most common form of anemia.
A decrease in zinc, which is part of enzymes that coordinate or catalyze iron metabolism, can impair iron absorption.
A case-control study with 30 iron deficiency patients and 30 healthy control persons showed that the serum zinc values in the patients with iron deficiency anemia were lower than in the healthy test persons.
Zinc deficiency was associated with worse cardiovascular complaints, epithelial symptoms and restless legs syndrome in the patients.
Therefore, zinc level determination should also be considered in patients with iron deficiency anemia.
Especially in the case of severe epithelial dysfunction, both iron and zinc should be supplemented and not just iron.
(Source: Abdo Soliman JS, Amer AY, Abdo Soliman JS. Association of zinc deficiency with iron deficiency anemia and its symptoms: Results from a case-control study. Cureus. 2019 Jan 2; 11 (1): e3811)
Zinc status in cystic fibrosis
Zinc is an essential micronutrient for all forms of life.
A deficit affects the normal growth and development of people.
In a Spanish cross-sectional study with 17 cystic fibrosis patients, 41% were at risk of zinc deficiency, which is why zinc supplementation should be considered.
(Source: Escobedo Monge MF, Barrado E, Alonso Vicente C et al .: Zink nutritional status in patients with cystic fibrosis. Nutrients. 2019 Jan 11; 11 (1))
An adequate supply of zinc to the mother reduces the risk of premature birth
There is evidence that inadequate maternal zinc status during pregnancy is associated with miscarriages, limited fetal growth, and neural tube defects.
A Chinese study with 3,081 mothers also suggests that maternal zinc concentrations during pregnancy are inversely related to the risk of premature births. Results are based on serum zinc levels from the first trimester. The incidence of premature birth was 7.3% in women with low serum zinc levels and 6.0% in participants with mediocre values. At high values it was only 3.1%.
(Source: Wang H et al., Maternal serum zinc concentration during pregnancy is inversely associated with risk of preterm birth in a Chinese population. J Nutr, March 1, 2016 vol. 146 no. 3 509-515)
A zinc deficiency promotes febrile seizures in children.
Febrile seizures occur mainly between the 6th month and the 5th year of life. 3 to 4% of children in this age group are affected (source: Pschyrembel 2014). 18 studies in a systematic review by Iranian researchers, which included a total of 20 studies, show that the serum zinc values in patients suffering from febrile seizures were significantly lower than in the control group. The work indicates that a zinc deficiency can promote febrile seizures.
(Source: Nasehi MM et al., Comparison of Serum Zinc Levels among Children with Simple Febrile Seizure and Control Group: A systematic Review. Iran J Child Neurol. 2015 Winter; 9 (1): 17-24