Why is Zinc So Important in your Immune System?

Zinc plays many vital roles in your immune system and it’s essential for proper immune function. In fact, a recent scientific review concluded: “It seems that every immunological event is influenced by zinc somehow.” (1)

Research has not yet determined all the ways zinc affects your immune system. But having an adequate intake of zinc has been shown to reduce your risk of contracting many different bacterial, fungal, parasitic, and viral infections, such as colds and flu, tuberculosis, pneumonia, measles and chronic hepatitis C. (2)

Your immune system consists of a vast network of tissues and specialized cells throughout your body that work together to protect you from infection. A healthy immune system can identify a variety of pathogens, and then coordinate an attack against them.  

This involves many specialized immune functions that monitor for potential threats and trigger responses when one is detected.

What follows are some of these vital immune functions and zinc’s role in each of them.

White Blood Cell Production

Your immune system includes various types of white blood cells. These cells circulate throughout your entire body, constantly searching for pathogens. When they find one, they start to multiply and send out signals for other immune cells to do the same.

Zinc is essential for the production of various types of white blood cells, particularly the cells called T lymphocytes and B lymphocytes, also known as T cells and B cells. Both of these cells can recognize foreign invaders your body has seen before, as well as help coordinate an immune response. 

The thymus, a small organ located in front of your heart, is where T cells develop. And zinc deficiency has been shown to cause your thymus to physically shrink and deplete your body of T cells. (3) Although, when those who are zinc deficient start consuming more zinc, the thymus quickly returns to normal and T cells are replenished.

It’s a similar story for B cells. They’re produced in your bone marrow, and zinc deficiency has been shown to impair their development. Research has shown that when mice were fed a marginally zinc-deficient diet for just 30 days, their total B cells dropped by nearly 75%. (4) This included both mature and immature B cells, although there was a greater impact on the immature cells.

Immune Cell Functions

When your immune system detects a potential pathogen, it triggers a complex system of chemical and cellular signals in your body that start your immune response. 

The responsiveness of many types of immune cells to these important signals is dependent on zinc. For example, zinc is required for the chemical signals to trigger the development of more T cells in your thymus when an infection is found. Without enough zinc, this system breaks down and not enough T cells are released to help fight an infection. (5)

The functions of a number of other white blood cells, including natural killer cells, are also shown to be impaired in the case of zinc deficiency. On the other hand, zinc supplementation has been shown to boost white blood cell function and assist the immune system in launching an effective first-response to an infection. (6) 

Zinc Regulation as a Defense Mechanism

The vast majority of zinc in your body is bound to various proteins and does not circulate as free ions. These proteins transport zinc to where it’s needed throughout your body. They also help regulate your zinc levels.

And strangely enough, this regulation of zinc can act as a defense against pathogens.

Just like humans, pathogens require zinc for their growth and survival. And your immune system uses this to its advantage by limiting zinc in areas of infection. It does this by keeping zinc bound to proteins and preventing it from circulating freely, where pathogens could access it.

Individual white blood cells also make use of zinc to help destroy pathogen cells. One type of white blood cell called a macrophage can directly reduce the zinc content in certain fungal cells, which weakens and eventually destroys them. (7) On the other hand, macrophages can kill specific bacteria by flooding them with excessive, toxic amounts of zinc and copper. (8)

Whether zinc is being restricted or released in excess, the regulation of zinc is an effective way for your immune system to control and destroy pathogens.

Physical Barriers for Immunity

Zinc is necessary for stabilizing individual cell membranes and keeping them strong. 

When it comes to immunity, this is especially important for the cellular linings of your lungs and intestines, which are constantly exposed to pathogens from your environment.

Zinc deficiency is proven to weaken these linings on a cellular level, which allows pro-inflammatory cells to cross into the surrounding tissues and potentially contribute to further lung and intestinal diseases. (9) Although, this issue has also been shown to correct itself with adequate zinc consumption.

Zinc also contributes to skin strength and health. This is one reason why topical zinc creams have been shown to enhance wound healing. (10)

 

Conclusion

Zinc is essential for proper immune function and appears to be involved in nearly every aspect of your immune system.

Various white blood cells require zinc for their development and proper functioning. 

Your immune system uses zinc as a form of defense by regulating the amount of zinc present at an infection site.

Zinc also stabilizes the structure of cells, including the cells that line your lungs and intestines. This is vital for providing a physical barrier against external pathogens and infection.

For those who eat a primarily plant-based diet, it is important to understand how the anti-nutrient phytate, which is present on all grains, nuts and seeds, can bind to zinc and prevent its absorption.  However, the enzyme phytase can counteract the negative effects of phytate, and give you access to the natural levels of zinc found in your foods. To find out more and to make sure you’re getting enough zinc and other essential minerals in your diet, click here.

References

(1) Gammoh NZ, Rink L. Zinc in infection and inflammation. Nutrients. 2017;9(6):624.

(2) Overbeck S, Rink L, Haase H. Modulating the immune response by oral zinc supplementation: a single approach for multiple diseases. Arch Immunol Ther Exp (Warsz). 2008;56(1):15-30.

(3) Shankar AH, Prasad AS. Zinc and immune function: the biological basis of altered resistance to infection. Am J Clin Nutr. 1998;68(2 Suppl):447S-463S.

(4) Shankar AH, Prasad AS. Zinc and immune function: the biological basis of altered resistance to infection. Am J Clin Nutr. 1998;68(2 Suppl):447S-463S.

(5) Shankar AH, Prasad AS. Zinc and immune function: the biological basis of altered resistance to infection. Am J Clin Nutr. 1998;68(2 Suppl):447S-463S.

(6) Gammoh NZ, Rink L. Zinc in infection and inflammation. Nutrients. 2017;9(6):624.

(7) Subramanian Vignesh K, Landero Figueroa JA, Porollo A, Caruso JA, Deepe GS Jr. Granulocyte macrophage-colony stimulating factor induced Zn sequestration enhances macrophage superoxide and limits intracellular pathogen survival. Immunity. 2013;39(4):697-710.

(8) Botella H, Stadthagen G, Lugo-Villarino G, Chastellier C, de Neyrolles O. Metallobiology of host-pathogen interactions: An intoxicating new insight. Trends Microbiol. 2012;20(3):106-12.

(9) Finamore A, Massimi M, Conti Devirgiliis L, Mengheri E. Zinc deficiency induces membrane barrier damage and increases neutrophil transmigration in Caco-2 cells. J Nutr. 2008;138(9):1664-70.

(10) Lansdown ABG, Mirastschijski U, Stubbs N, Scanlon E, Agren MS. Zinc in wound healing: Theoretical, experimental, and clinical aspects. Wound Repair Regen. 2007;15(1):2-16.