Zinc — Mineral Extraordinaire

With current events in world and at the time this article is being written landing in the dead of winter, immune system health is a very hot topic and an item that is often mentioned in the same breath is the essential mineral — Zinc. Known to be especially popular this time of year and available in many commercially available supplements, its benefits are not limited just to immune system health. There are a host of benefits and vital functions that zinc plays a role in and the goal of today’s article is to dive in headfirst and take a look at the research.

Zinc — What is it?

An essential mineral, zinc is found naturally in high levels in sources such as eggs, animal tissues, fish, and legumes with particularly high levels in foods like oysters and shellfish. It is a highly active cofactor that plays a role in over 300 enzymes related to gene expression, signal transduction and proliferation in cells and deficiencies of this mineral can reduce the activity of these crucial enzymes1,2. A deeper look into the biology of zinc shows that its primary role with enzymes is that of a prosthetic group called metalloproteins which include a Superoxide Dismutase enzyme which is an endogenous antioxidant involving both zinc and copper as well as immune system regulation (which I’ll cover later in the article)1,3.

Forms of Zinc

There have been several forms of zinc on the market available for consumer use, both as formulated with other ingredients as well as standalone. Included in these are Zinc Citrate, Zinc Gluconate, Zinc Picolinate and Zinc Carnosine.

Zinc citrate contains the zinc salt form of citric acid and zinc gluconate is the zinc salt form of gluconic acid. Both of these are traditionally used as basic supplemental forms of zinc and are often the ones utilized commonly for helping to alleviate the common cold and zinc gluconate appears to have the edge in terms of absorption compared to citrate4.

Zinc Picolinate which is elemental zinc bound to picolinic acid (a metabolite of the amino acid tryptophan). One of the most readily absorbed time-tested versions on the market of zinc is Zinmax® from Nutrition 21. It is used in a wide array of applications on the market for its increased bioavailability via enhanced absorption from the intestine and consistent quality and is my preferred version of zinc in my own formulation work . You can read more about Zinmax® here.

One last form of zinc that is important to cover is Zinc Carnosine which is a synthetic molecule in which zinc and carnosine are linked together, creating a polymer like structure. This form is best known for its use stemming from Japan in helping to alleviate gastritis and gastric ulcers and promoting overall gastric integrity5.

Zinc Deficiencies

From research data, it has been determined that in general, zinc deficiency does seem to be a bit of an issue with roughly 10% of individuals in the United States intake less than half of the RDA for zinc while the global rate is an astounding 50% deficiencies (possibly skewed due to data from 3rd world countries)6. It is especially problematic to have a deficiency in youth as inadequate zinc intake has been related to hypogonadism in adult males as well as skin abnormalities and general mental lethargy7.

There is also an interesting correlation between zinc deficiencies following exercise. Zinc is among the critical minerals lost in sweat and may result in predisposing athletes to zinc deficiency. Made famous by the introduction of ZMA by Victor Conte, a few studies in particular highlight the importance of zinc with the first being a 1998 study conducted on NCAA football players over an 8 week spring training program, finding then compared to the control group, there were greater increases in muscle strength8 It is also important to note that data has suggested that prolonged strenuous exercise can suppress the immune system9,10. As we’ll discuss later in the article, this would be another great reason to include a high-quality zinc supplement such as Zinmax® as one of the key benefits is immune system support.

Subsequent studies following this one took another look at this aspect and didn’t find as promising results in boosting testosterone, IGF-1, GH or strength markers so when zinc levels are adequate, there doesn’t appear to be much added benefit from supplementing11,12. However, if an athlete is truly zinc deficient as a result of sweating and non-replenishment of zinc, it has been observed that it could be a contributing factor to depressed testosterone levels following exhaustive exercise13.

Those at an increased risk for zinc deficiency include people with gastrointestinal disease, vegetarians/vegans, pregnant/breastfeeding women, sickle cell anemia patients, chronic kidney disease patients, people who suffer from malnourishment and last but not least, those with alcohol abuse problems14. Symptoms can include decreased immunity, thinning hair, decreased appetite impaired wound healing and mood disturbances15.

Zinc Benefits

As noted earlier in the article, there are several crucial processes that zinc plays a role in and having a deficiency can severely impact these processes. For the scope of the article, we will focus on the items that have the strongest body of research findings. First up is that that with wintertime, most think of zinc as a perfect component of bolstering immune system health. Zinc directly affects multiple aspects of the immune system including development and function of cells mediating innate immunity, barrier of skin to gene regulation with lymphocytes, normal development and function of cells mediating nonspecific immunity including neutrophils and natural killer cells and cytokine production. Macrophages which are a pivotal cell in immunologic function can also be affected if there is a zinc deficiency as is apoptosis. Lastly regarding immune function and cellular health, it should be noted that zinc also functions as a potent antioxidant that can stabilize cell membranes16.

Memory/Learning is another aspect that is influenced by adequate zinc intake as it is highly concentrated in the hippocampus and deficiency of zinc is associated with both mood disorders and impaired memory formation17,18. This issue with memory formation seems to be related to spatial memory and brain-derived neurotrophic factor (BDNF) signaling and improving zinc status has been shown to be associated with betterment in symptoms. Inversely, abnormally high zinc intake (60ppm) can also impair memory as well so there does appear to be a sweet spot19.

Zinc Summarized

As you can see, zinc is more than just another mineral. It is one of the single most important elements out there that plays a large role in literally hundreds of processes in the body and sadly is one that when it is sufficient in diet goes unnoticed, but when a deficiency occurs, the issues rear their ugly head. Vital for proper immune function and memory formation by nature, you could consider zinc one of the single most important minerals in maintaining overall health. General supplementation of 50mg a day of a high bioavailability zinc such as Zinmax® can provide a host of positive benefits and keep you up and running for the long term.

References

1. Vallee B. The biochemical basis of zinc physiology. Physiol Rev. 1993;73(1):79–118. doi:10.1152/physrev.1993.73.1.79

2. Haase H. Functional significance of zinc-related signaling pathways in immune cells. Annu Rev Nutr. 2009;29:133–152. doi:10.1146/annurev-nutr-080508–141119.

3. Anzellotti A. Zinc metalloproteins as medicinal targets. Chem Soc Rev. 2008;37(8):1629–1651. doi:10.1039/b617121b

4. Barrie S. Comparative absorption of zinc picolinate, zinc citrate and zinc gluconate in humans. Agents & Actions. 1987;21(1–2):223–228. doi:10.1007/BF01974946

5. Korolkiewicz R. Polaprezinc exerts a salutary effect on impaired healing of acute gastric lesions in diabetic rats. Dig Dis Sci. 2000;45(6):1200–1209. doi:10.1023/a:1005566406257

6. Takeda A. Insight into zinc signaling from dietary zinc deficiency. Brain Res Rev. 2009;11(62):33–44. doi:10.1016/j.brainresrev.2009.09.003

7. Prasad A. Clinical manifestations of zinc deficiency. Annu Rev Nutr. 1985;5:341–363. doi:10.1146/annurev.nu.05.070185.002013

8. Brilla L, Conte V. Effects of a novel zinc-magnesium formulation on hormones and strength. J Ex Phys Online. 2000;3(4):26–36.

9. Atias-Varon D. STRENUOUS AND PROLONGED EXERCISE AND UPPER RESPIRATORY TRACT INFECTION — TREATMENT OR THREAT? Harefua. 2017;156(11):730–734.

10. Jeurissen A. The effects of physical exercise on the immune system. Ned Tijdschr Geneeskd. 2003;147(28):1347–1351.

11. Wilborn C. Effects of Zinc Magnesium Aspartate (ZMA) Supplementation on Training Adaptations and Markers of Anabolism and Catabolism. J Int Soc Sports Nutr. 2004;1(2):12–20. doi:10.1186/1550–2783–1–2–12

12. Koehler K. Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement. Eur J Clin Nutr. 2009;63:65–70. doi:10.1038/sj.ejcn.1602899

13. Hackney A. Comparison of the hormonal responses to exhaustive incremental exercise in adolescent and young adult males. Arq Bras Endorinol Metabol. 2011;55(3):213–218. doi:10.1590/s0004–27302011000300006

14. Kumssa D. Dietary calcium and zinc deficiency risks are decreasing but remain prevalent. Sci Rep. 2015;5(10974). doi:10.1038/srep10974

15. Saper R. Zinc: An Essential Micronutrient. Am Fam Physician. 2009;79(9):768.

16. Shankar A. Zinc and immune function: the biological basis of altered resistance to infection. Am J Clin Nutr. 1998;68(2):447S-463S. doi:10.1093/ajcn/68.2.447S

17. Frederickson C. Importance of zinc in the central nervous system: the zinc-containing neuron. J Nutr. 2000;130(SS Suppl):1471S-83S. doi:10.1093/jn/130.5.1471S

18. Tahmasebi Boroujeni S. The effect of severe zinc deficiency and zinc supplement on spatial learning and memory. Biol Trace Elemen Res. 2009;130(1):48–61. doi:10.1007/s12011–008–8312–7

19. Yang Y. High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling. PLoS One. 2013;8(1):E55384. doi:10.1371/journal.pone.0055384