Zinc

Main Points

• Zinc is one of 24 micronutrients necessary for survival.
• As many as 2 billion people worldwide are deficient in zinc.
• Zinc is required for numerous enzymatic processes, and plays a role in healthy hormone function, immune function, and neurological health.
• Zinc is also involved in increasing serotonin uptake in the brain.

Good Sources

• Meat, eggs, legumes, oysters.

How to Take

• 5-10 mg with meals as a daily preventative dose, or 25-45 mg daily for those at risk for zinc deficiency.

Natural Stacks Supplements Containing Zinc

• Serotonin Brain Food™
• Vitamin C with Zinc Glycinate

Effects On Brain Health

Zinc provides a wide variety of general health benefits and it may positively influence cognition, mood, and well-being. Interestingly, both a deficiency and a surplus of zinc in the brain have been correlated with memory impairment [1, 2].

Effects On Cognition

Zinc supplementation has been shown to improve cognitive performance and taste acuity in a study of adolescent girls [3].

Additionally, correcting for zinc deficiencies has been shown to restore memory and cognition in stroke patients [4].

Effects On Memory and Learning

Zinc is highly concentrated in the hippocampus region of the brain, and deficiency of this mineral is associated with both mood disorders and impaired memory formation [5, 6, 7]. Specifically, zinc deficiency is highly correlated with decrements in spatial memory, thought to result from impaired BDNF signaling (a pathway associated with neuronal growth and plasticity) [8, 9, 10].

In a mouse model, zinc-fortified water given throughout the lifespan had neuroprotective effects compared to control, indicating that zinc may aid in preventing decline in memory over time [11].

It is theorized that zinc may reduce the accumulation of the protein beta-amyloid (which is linked to the onset of neurodegenerative diseases) in the brain as well as improve mitochondrial function and BDNF levels [12].

Effects On Mood

Depressed patients appear to have reduced levels of serum zinc, and the magnitude of the deficiency is related to the severity of the depression [13, 14, 15]. 

Zinc supplementation is effective as an adjunct therapy alongside traditional antidepressants, but it may also reduce depressive symptoms in otherwise healthy individuals via increased BDNF [16].

The results of a 6-month trial showed improvements in mood in a population of young, healthy women after supplementing with 7 mg elemental zinc [17]. Another study showed that 30 mg elemental zinc taken daily for 12 weeks was associated with improvements in depressive symptoms compared to placebo [18].

Studies involving rats have shown that depressive and behavioral symptoms were improved upon normalizing zinc levels after a period of two weeks of zinc deprivation [19, 20].

Zinc is thought to inhibit the enzyme glycogen synthase kinase-3B (BSK3B) which is a molecular target for mood disorders [21, 22, 23].

Side Effects

Cases of nausea have been reported when zinc is taken on an empty stomach and at high doses.

References

1. Yang, Y., Jing, X. P., Zhang, S. P., Gu, R. X., Tang, F. X., Wang, X. L., ... & Wang, J. Z. (2013). High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling. PLoS One, 8(1), e55384.
2. Flinn, J. M., Hunter, D., Linkous, D. H., Lanzirotti, A., Smith, L. N., Brightwell, J., & Jones, B. F. (2005). Enhanced zinc consumption causes memory deficits and increased brain levels of zinc. Physiology & behavior, 83(5), 793-803.
3. Tupe, R. P., & Chiplonkar, S. A. (2009). Zinc supplementation improved cognitive performance and taste acuity in Indian adolescent girls. Journal of the American College of Nutrition, 28(4), 388-396.
4. Aquilani, R., Baiardi, P., Scocchi, M., Iadarola, P., Verri, M., Sessarego, P., ... & Viglio, S. (2009). Normalization of zinc intake enhances neurological retrieval of patients suffering from ischemic strokes. Nutritional neuroscience, 12(5), 219-225.
5. Frederickson, C. J., Suh, S. W., Silva, D., Frederickson, C. J., & Thompson, R. B. (2000). Importance of zinc in the central nervous system: the zinc-containing neuron. The Journal of nutrition, 130(5), 1471S-1483S.
6. Frederickson, C. J., Klitenick, M. A., Manton, W. I., & Kirkpatrick, J. B. (1983). Cytoarchitectonic distribution of zinc in the hippocampus of man and the rat. Brain research, 273(2), 335-339.
7. Boroujeni, S. T., Naghdi, N., Shahbazi, M., Farrokhi, A., Bagherzadeh, F., Kazemnejad, A., & Javadian, M. (2009). The effect of severe zinc deficiency and zinc supplement on spatial learning and memory. Biological trace element research, 130(1), 48-61.
8. Klein, A. B., Williamson, R., Santini, M. A., Clemmensen, C., Ettrup, A., Rios, M., ... & Aznar, S. (2011). Blood BDNF concentrations reflect brain-tissue BDNF levels across species. International Journal of Neuropsychopharmacology, 14(3), 347-353.
9. Leal, G., Comprido, D., & Duarte, C. B. (2014). BDNF-induced local protein synthesis and synaptic plasticity. Neuropharmacology, 76, 639-656.
10. Mizuno, M., Yamada, K., He, J., Nakajima, A., & Nabeshima, T. (2003). Involvement of BDNF receptor TrkB in spatial memory formation. Learning & memory, 10(2), 108-115.
11. Corona, C., Masciopinto, F., Silvestri, E., Del Viscovo, A., Lattanzio, R., La Sorda, R., ... & Sensi, S. L. (2010). Dietary zinc supplementation of 3xTg-AD mice increases BDNF levels and prevents cognitive deficits as well as mitochondrial dysfunction. Cell death & disease, 1(10), e91.
12. Corona, C., Masciopinto, F., Silvestri, E., Del Viscovo, A., Lattanzio, R., La Sorda, R., ... & Sensi, S. L. (2010). Dietary zinc supplementation of 3xTg-AD mice increases BDNF levels and prevents cognitive deficits as well as mitochondrial dysfunction. Cell death & disease, 1(10), e91.
13. Maes, M., Vandoolaeghe, E., Neels, H., Demedts, P., Wauters, A., Meltzer, H. Y., ... & Desnyder, R. (1997). Lower serum zinc in major depression is a sensitive marker of treatment resistance and of the immune/inflammatory response in that illness. Biological psychiatry, 42(5), 349-358.
14. Maes, M., D'haese, P. C., Scharpé, S., D'Hondt, P., Cosyns, P., & De Broe, M. E. (1994). Hypozincemia in depression. Journal of Affective Disorders, 31(2), 135-140.
15. Amani, R., Saeidi, S., Nazari, Z., & Nematpour, S. (2010). Correlation between dietary zinc intakes and its serum levels with depression scales in young female students. Biological trace element research, 137(2), 150-158.
16. Siwek, M., Dudek, D., Paul, I. A., Sowa-Kućma, M., Zięba, A., Popik, P., ... & Nowak, G. (2009). Zinc supplementation augments efficacy of imipramine in treatment resistant patients: a double blind, placebo-controlled study. Journal of affective disorders, 118(1), 187-195.
17. Sawada, T., & Yokoi, K. (2010). Effect of zinc supplementation on mood states in young women: a pilot study. European journal of clinical nutrition, 64(3), 331-333.
18. Solati, Z., Jazayeri, S., Tehrani-Doost, M., Mahmoodianfard, S., & Gohari, M. R. (2015). Zinc monotherapy increases serum brain-derived neurotrophic factor (BDNF) levels and decreases depressive symptoms in overweight or obese subjects: a double-blind, randomized, placebo-controlled trial. Nutritional neuroscience, 18(4), 162-168.
19. Tamano, H., Kan, F., Kawamura, M., Oku, N., & Takeda, A. (2009). Behavior in the forced swim test and neurochemical changes in the hippocampus in young rats after 2-week zinc deprivation. Neurochemistry international, 55(7), 536-541.
20. Watanabe, M., Tamano, H., Kikuchi, T., & Takeda, A. (2010). Susceptibility to stress in young rats after 2-week zinc deprivation. Neurochemistry international, 56(3), 410-416.
21. Ilouz, R., Kaidanovich, O., Gurwitz, D., & Eldar-Finkelman, H. (2002). Inhibition of glycogen synthase kinase-3β by bivalent zinc ions: insight into the insulin-mimetic action of zinc. Biochemical and biophysical research communications, 295(1), 102-106.
22. Gould, T. D., Picchini, A. M., Einat, H., & Manji, H. K. (2006). Targeting glycogen synthase kinase-3 in the CNS: implications for the development of new treatments for mood disorders. Current drug targets, 7(11), 1399-1409.
23. Little, K. Y., Castellanos, X., Humphries, L. L., & Austin, J. (1989). Altered zinc metabolism in mood disorder patients. Biological psychiatry, 26(6), 646-648.