Coronavirus (45) Nutrients help to combat COVID-19 (cont’d)
In addition to the vitamins mentioned in my last blog post, minerals such as iron, zinc, selenium and copper are also essential for good immunity. They are required in smaller quantities and are therefore called trace minerals. Let us have a look at the same two review articles1,2 used in the last blog post, on how different trace minerals can protect ourselves from infectious diseases.
Copper
Copper itself is an antimicrobe. Copper supports neutrophil, monocyte and macrophage function and natural killer cell activity.
People on a low copper diet have decreased lymphocyte proliferation and decreased production of IL-2, which is important for immune response. Children with Menke’s syndrome, a rare congenital disease with no circulating copper-carrying protein caeruloplasmin, show immune impairments and have increased bacterial infections and pneumonia. Analysis of studies on Chinese children showed that those with recurrent respiratory tract infection were more likely to have low levels of copper in their hair.1
Iron
Iron is a trace mineral that we should be careful about the amount we take in. Iron is required for both host and pathogen. Iron deficiency can impair host immunity, while iron overload can cause oxidative stress to propagate harmful viral mutations.2
Iron deficiency has harmful effects on immune function, including impairment of: 1. the ability to generate reactive oxygen species for the killing of harmful microorganisms; 2. bacterial killing; 3. natural killer cell activity; 4. T lymphocyte proliferation, and 5. production of T helper 1 cytokines. These in turn increase susceptibility to infection.1
On the other hand, infections caused by organisms that spend part of their life-cycle intracellularly may actually be enhanced by iron. In the children living in tropical regions, iron at doses above a particular threshold has been associated with increased risk of malaria and other infections, including pneumonia. Thus, iron intervention in malaria-endemic areas is not advised.1 Moreover, a study giving iron (50 mg on each of 4 days a week) to iron-deficient schoolchildren in South Africa increased the risk of respiratory infections.1
In general, the harmful consequences of iron overdoses on infections include: 1. Impairment of immune function; 2. Excess iron favours damaging inflammation; 3. Helping the growth of pathogens that require iron.
Selenium
Selenium deficiency adversely affects several components of both innate* and acquired immunity,** and increases susceptibility to infections.1
It is of concern to find that dietary selenium deficiency induces rapid mutation of benign variants of RNA viruses to virulence. Deficiency in selenium can cause oxidative stress in the host, and can alter a viral genome so that a normally benign or mildly pathogenic virus can become highly virulent.2 Selenium could assist a group of enzymes that, in concert with vitamin E, work to prevent the formation of free radicals and prevent oxidative damage to cells and tissues.
It was reported that combination of selenium with ginseng stem-leaf saponins could induce immune response to a live bivalent infectious bronchitis coronavirus vaccine in chickens.2 Therefore, the review article written by Zhang et al suggests that selenium supplementation could be an effective choice for the treatment of novel variants of COVID-19.2
You may wonder how much selenium we need to maintain the normal function of our immunity. It was found that selenium supplementation with 100 to 300 µg/day could improve various aspects of immune function in humans including in the elderly. Selenium supplementation of 50 or 100 µg/day in adults in the UK with low selenium status improved some aspects of their immune response to a poliovirus vaccine.1
Zinc
Zinc has an important role in maintaining and developing immune cells of both the innate* and adaptive immune system.***
Especially you may find it interesting that zinc seems to play an important role in antiviral defence. It was found to inhibit the RNA polymerase required by RNA viruses to replicate. Moreover, zinc supports proliferation of CD8+ cytotoxic T lymphocytes, key cells in antiviral defence. These findings suggest that zinc might play a key role in host defence against the RNA virus SARS-CoV-2 that cause COVID-19.1 In fact, the combination of zinc and pyrithione at low concentrations inhibits the replication of SARS coronavirus.2
Zinc deficiency has a marked impact on bone marrow by decreasing the number of immune precursor cells. Therefore, zinc is important in maintaining T and B lymphocyte numbers. Moreover, antibody production is decreased in zinc deficiency. Zinc deficiency also impairs many aspects of innate immunity, including phagocytosis and natural killer cell activity. Patients with the zinc malabsorption syndrome, acrodermatitis enteropathica, display severe immune impairments and increased susceptibility to bacterial, viral and fungal infections.1
Correcting zinc deficiency lowers the likelihood of respiratory and skin infections. Recent reviews and analysis of trials with zinc reported shorter durations of common cold in adults, reduced incidence and prevalence of pneumonia in children, and reduced mortality when given to adults with severe pneumonia.1
Conclusion
After reading the two blog posts on the different nutrients and their importance in fighting against infection, we understand we should have a balanced diet in order to maintain our immune system to prevent respiratory diseases such as COVID-19. No single nutrient should be left out in order to attain the optimum condition of our immune system for health.
As new pathogens responsible for influenza continually emerge, and outbreaks of new variants of the SARS-CoV-2 virus are highly possible, it is especially necessary to have a dietary regimen that includes all the nutrients in order to reduce the adverse effects from new or mutating pathogens.
*The innate immune system is the body’s first line of defense against germs. The innate immune system consists of 1. skin and mucous membranes that forms a physical barrier against germs; 2. immune system cells (defense cells) and proteins that are activated upon inflammation; 3. white blood cells (leukocytes) that kill bacteria or viruses, by phagocytosis, that enter the body; 4. natural killer cells specialized in identifying cells that are infected by a virus, and then destroy the cell surface using cell toxins.3
Since the innate immune system responds in the same way to all germs and foreign substances, it is also referred to as the "nonspecific" immune system. It acts very quickly: it makes sure that bacteria that have entered the skin through a small wound are detected and destroyed on the spot within a few hours. However, the innate immune system has only limited power to stop germs from spreading.3
**“Acquired immunity is a type of immunity that develops when a person’s immune system responds to a foreign substance or microorganism, or that occurs after a person receives antibodies from another source. The two types of acquired immunity are adaptive and passive. Adaptive immunity occurs in response to being infected with or vaccinated against a microorganism. The body makes an immune response, which can prevent future infection with the microorganism. Passive immunity occurs when a person receives antibodies to a disease or toxin rather than making them through his or her own immune system.” (from online NCI (National Cancer Institute) dictionary. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/acquired-immunity)
***The adaptive immune system takes over if the innate immune system is not able to destroy the germs. The adaptive immune system is made up of 1. T lymphocytes in the tissue between the body's cells; 2. B lymphocytes which are also found in the tissue between the body's cells; 3. antibodies in the blood and other bodily fluids.
The adaptive immune system specifically targets the type of germ that is causing the infection. It first identifies the germ, which makes it slower to respond than the innate immune system, and then it destroys it. It can "remember" germs, so the next time a known germ is encountered, the adaptive immune system can respond faster.
References
1. P.C. Calder. Nutrition, immunity and COVID-19. Review. BMJ Nutrition, Prevention & Health. 2020 May 20;3(1):74-92.
2. L. Zhang, and Y. Liu. Potential interventions for novel coronavirus in China: A systematic review. Journal of Medical Virology, 2020 May 92(5):479-490.
3. The innate and adaptive immune systems. InformedHealth.org. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. https://www.ncbi.nlm.nih.gov/books/NBK279396/
In addition to the vitamins mentioned in my last blog post, minerals such as iron, zinc, selenium and copper are also essential for good immunity. They are required in smaller quantities and are therefore called trace minerals. Let us have a look at the same two review articles1,2 used in the last blog post, on how different trace minerals can protect ourselves from infectious diseases.
Copper
Copper itself is an antimicrobe. Copper supports neutrophil, monocyte and macrophage function and natural killer cell activity.
People on a low copper diet have decreased lymphocyte proliferation and decreased production of IL-2, which is important for immune response. Children with Menke’s syndrome, a rare congenital disease with no circulating copper-carrying protein caeruloplasmin, show immune impairments and have increased bacterial infections and pneumonia. Analysis of studies on Chinese children showed that those with recurrent respiratory tract infection were more likely to have low levels of copper in their hair.1
Iron
Iron is a trace mineral that we should be careful about the amount we take in. Iron is required for both host and pathogen. Iron deficiency can impair host immunity, while iron overload can cause oxidative stress to propagate harmful viral mutations.2
Iron deficiency has harmful effects on immune function, including impairment of: 1. the ability to generate reactive oxygen species for the killing of harmful microorganisms; 2. bacterial killing; 3. natural killer cell activity; 4. T lymphocyte proliferation, and 5. production of T helper 1 cytokines. These in turn increase susceptibility to infection.1
On the other hand, infections caused by organisms that spend part of their life-cycle intracellularly may actually be enhanced by iron. In the children living in tropical regions, iron at doses above a particular threshold has been associated with increased risk of malaria and other infections, including pneumonia. Thus, iron intervention in malaria-endemic areas is not advised.1 Moreover, a study giving iron (50 mg on each of 4 days a week) to iron-deficient schoolchildren in South Africa increased the risk of respiratory infections.1
In general, the harmful consequences of iron overdoses on infections include: 1. Impairment of immune function; 2. Excess iron favours damaging inflammation; 3. Helping the growth of pathogens that require iron.
Selenium
Selenium deficiency adversely affects several components of both innate* and acquired immunity,** and increases susceptibility to infections.1
It is of concern to find that dietary selenium deficiency induces rapid mutation of benign variants of RNA viruses to virulence. Deficiency in selenium can cause oxidative stress in the host, and can alter a viral genome so that a normally benign or mildly pathogenic virus can become highly virulent.2 Selenium could assist a group of enzymes that, in concert with vitamin E, work to prevent the formation of free radicals and prevent oxidative damage to cells and tissues.
It was reported that combination of selenium with ginseng stem-leaf saponins could induce immune response to a live bivalent infectious bronchitis coronavirus vaccine in chickens.2 Therefore, the review article written by Zhang et al suggests that selenium supplementation could be an effective choice for the treatment of novel variants of COVID-19.2
You may wonder how much selenium we need to maintain the normal function of our immunity. It was found that selenium supplementation with 100 to 300 µg/day could improve various aspects of immune function in humans including in the elderly. Selenium supplementation of 50 or 100 µg/day in adults in the UK with low selenium status improved some aspects of their immune response to a poliovirus vaccine.1
Zinc
Zinc has an important role in maintaining and developing immune cells of both the innate* and adaptive immune system.***
Especially you may find it interesting that zinc seems to play an important role in antiviral defence. It was found to inhibit the RNA polymerase required by RNA viruses to replicate. Moreover, zinc supports proliferation of CD8+ cytotoxic T lymphocytes, key cells in antiviral defence. These findings suggest that zinc might play a key role in host defence against the RNA virus SARS-CoV-2 that cause COVID-19.1 In fact, the combination of zinc and pyrithione at low concentrations inhibits the replication of SARS coronavirus.2
Zinc deficiency has a marked impact on bone marrow by decreasing the number of immune precursor cells. Therefore, zinc is important in maintaining T and B lymphocyte numbers. Moreover, antibody production is decreased in zinc deficiency. Zinc deficiency also impairs many aspects of innate immunity, including phagocytosis and natural killer cell activity. Patients with the zinc malabsorption syndrome, acrodermatitis enteropathica, display severe immune impairments and increased susceptibility to bacterial, viral and fungal infections.1
Correcting zinc deficiency lowers the likelihood of respiratory and skin infections. Recent reviews and analysis of trials with zinc reported shorter durations of common cold in adults, reduced incidence and prevalence of pneumonia in children, and reduced mortality when given to adults with severe pneumonia.1
Conclusion
After reading the two blog posts on the different nutrients and their importance in fighting against infection, we understand we should have a balanced diet in order to maintain our immune system to prevent respiratory diseases such as COVID-19. No single nutrient should be left out in order to attain the optimum condition of our immune system for health.
As new pathogens responsible for influenza continually emerge, and outbreaks of new variants of the SARS-CoV-2 virus are highly possible, it is especially necessary to have a dietary regimen that includes all the nutrients in order to reduce the adverse effects from new or mutating pathogens.
*The innate immune system is the body’s first line of defense against germs. The innate immune system consists of 1. skin and mucous membranes that forms a physical barrier against germs; 2. immune system cells (defense cells) and proteins that are activated upon inflammation; 3. white blood cells (leukocytes) that kill bacteria or viruses, by phagocytosis, that enter the body; 4. natural killer cells specialized in identifying cells that are infected by a virus, and then destroy the cell surface using cell toxins.3
Since the innate immune system responds in the same way to all germs and foreign substances, it is also referred to as the "nonspecific" immune system. It acts very quickly: it makes sure that bacteria that have entered the skin through a small wound are detected and destroyed on the spot within a few hours. However, the innate immune system has only limited power to stop germs from spreading.3
**“Acquired immunity is a type of immunity that develops when a person’s immune system responds to a foreign substance or microorganism, or that occurs after a person receives antibodies from another source. The two types of acquired immunity are adaptive and passive. Adaptive immunity occurs in response to being infected with or vaccinated against a microorganism. The body makes an immune response, which can prevent future infection with the microorganism. Passive immunity occurs when a person receives antibodies to a disease or toxin rather than making them through his or her own immune system.” (from online NCI (National Cancer Institute) dictionary. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/acquired-immunity)
***The adaptive immune system takes over if the innate immune system is not able to destroy the germs. The adaptive immune system is made up of 1. T lymphocytes in the tissue between the body's cells; 2. B lymphocytes which are also found in the tissue between the body's cells; 3. antibodies in the blood and other bodily fluids.
The adaptive immune system specifically targets the type of germ that is causing the infection. It first identifies the germ, which makes it slower to respond than the innate immune system, and then it destroys it. It can "remember" germs, so the next time a known germ is encountered, the adaptive immune system can respond faster.
References
1. P.C. Calder. Nutrition, immunity and COVID-19. Review. BMJ Nutrition, Prevention & Health. 2020 May 20;3(1):74-92.
2. L. Zhang, and Y. Liu. Potential interventions for novel coronavirus in China: A systematic review. Journal of Medical Virology, 2020 May 92(5):479-490.
3. The innate and adaptive immune systems. InformedHealth.org. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. https://www.ncbi.nlm.nih.gov/books/NBK279396/
No comments:
Post a Comment