Can Zinc Supplements Reduce the Duration of Colds?

1. Can Zinc Supplements Reduce the Duration of Colds? NUTR 439: Communications in Dietetics May 18th, 2009 Sarah Hallaj

2. Outline: I. Introduction • Background information on zinc • Different forms of zinc supplements II. Body • How zinc supplements work with viruses • Research study that support the controversial issue • Research study that refute the controversial issue • Comparison of studies III. Conclusion • Do zinc supplements really work?

3. Zinc is an essential micronutrient mineral that has many functions in the human body. It provides both a structural, catalytic, and regulatory control on the cellular level in our bodies. Zinc plays a vital role in: • Neurological function • Growth and development • Immune function

4. The zinc RDA for adults is 11mg/day for males and 8mg/day for females. • Good food sources of zinc are found in meat products (oysters and beef) and in legumes and nuts. • Zinc in oysters and beef is more bioavailablethan in legumes and nuts due to the presence of cysteine and methionine amino acids which increase absorption1.

5. http://george-eby-research.com/gif/zinc-sources.jpg

6. So, what about zinc supplements?

7. The many different types of zinc supplements have been suggested to decrease the duration of colds; but still remains a controversial issue. • Some research studies support it while others claim that its disadvantages outweigh its benefits.

8. Zinc is found in many supplement forms such as: gels, lozenges, and sprays. • Different zinc compounds include: zinc sulfate, zinc acetate, and zinc gluconate. • Each of these compound forms differ in the amount of zinc provided and in absorption. • Some forms are more soluble than others2.

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10. Common Cold Viruses: • Increase oxidative stress • Activate macrophage and monocytes • Increase production of inflammatory molecules 3 Prasad. A. 2008.

11. How do zinc supplements work?

12. A review article hypothesized • Zinc inhibits rhinovirus particles from attaching to ICAM-1 (Inter-Cellular Adhesion Molecule 1) on the nasal epithelium • ICAM-1 is an anti-inflammatory molecule • Zinc prevent rhinovirus from replicating4 Hulisz, D. 2004.

13. Summary of a study • Randomized double-blind, placebo-controlled trial of zinc • Fifty healthy volunteers were recruited free of any illness • Participants took 1 lozenge of zinc acetate containing 13.3 mg zinc upon developing symptoms of cold • Placebo and zinc tablets were identical in shape, color, and sweetness in taste 3 Prasad. A. 2008.

14. Results: • Mean duration of cold was 4.0 days in the zinc group and 7.1 days in the placebo group • The duration of cough, nasal discharge, and mucous were significantly shorter in the zinc group • Zinc group has decreased plasma levels of inflammatory molecules (ICAM-1)

15. Zinc supplments work if: • Taken within 24hours of the onset of a cold • Taken every 2-3 hours while awake for 3-5 days • Taken in the form of zinc lozenges

16. Summary of another study: • Double-blind placebo-controlled clinical trial • Seventy seven participants had two or more symptoms of the common cold • Participants received 10 mmolzinc gluconate nasal spray every 15-30 minutes • Zinc orotate lozenges containing 37mg zinc were supplemented and taken every 2-3 hours while awake • Placebo was free of zinc but otherwise identical 5 Eby G. 2006.

17. Results: • No evidence of reduction of cold duration in both groups • Zinc group reported more adverse effects than placebo group • Some side effects included: mouth irritation, mouth sores, diarrhea, nasal pain and discomfort

18. Researchers explained that even though zinc orotate lozenges has high zinc concentrations, but it is slightly soluble in water and is non-ionizable under physiologic conditions • This explains why zinc lozenges did not have positive effects on cold duration

19. Zinc nasal sprays caused nasal pain and irritation • Researchers claimed that 10 mmol of zinc gluconate was the upper tolerable concentration that causes long lasting intra-nasal pain and anosmia • Anosmia is inability to perceive smell!!

20. Researchers explained that zinc, a heavy metal, passes via olfactory receptor neuron to the olfactory bulb, and reaching the nuclei of the brain Ionic zinc physically destroys olfactory epithelium and causes atrophy of the olfactory bulb producing anosmia

21. Comparing the studies • The studies were not all using the same controls, which might explain the differences in results. • Different zinc supplement forms and compounds • Different zinc amounts • Different duration of studies • Participating subjects were not of the same age groups (children and adults) and differences in ethnic backgrounds were not considered.

22. A common control point was that all subjects were asked to not take any other cold remedy while being observed for the study; with the exception of one study where the children received other drugs if they had a fever5. • All articles reviewed looked at the class of rhinoviruses that cause the most common type of cold. • One must keep in mind that it is hard to monitor subjects when they are at home.

23. Conclusion: • It is best to avoid using zinc nasal sprays due to irreversible anosmia-causing effects. • Short-term use of zinc lozenges shortens the duration of colds and does not resulted in serious side effects.

24. It is safe to use zinc lozenges within 24 hours on the onset of a cold every 2-3 hours while awake for 3-5 days . • If symptoms persist then one should refer to a physician.

25. References: • [1] Higdon, J. Zinc. Linus Pauling Institute Micronutrient Research for Optimum Health. 2008. Available at: http://lpi.oregonstate.edu/infocenter/minerals/zinc/index.html#rda. Accessed April 11, 2009. • [2] Gropper S, Smith J, Groff J. Advanced Nutrition And Human Metabolism. Belmont, CA: Wadsworth; 2005 • [3] Prasad A, Beck F, Bao B, Snell D, Fitzgerald J. Duration and Severity of Symptoms and Levels of Plasma Interleukin-1 Receptor Antagonist, Soluble Tumor Necrosis Factor Receptor, and Adhesion Molecules in Patients with Common Cold Treated with Zinc Acetate. J Infec Disease. [18279051]. 2008; 197: 795-802. Available at: http://proxy.library.oregonstate.edu/login?url=http://search.ebscohost.com/login.aspx?direct=true&db=cmedm&AN=18279051&loginpage=Login.asp&site=ehost-live. Accessed April 11, 2009. • [4] Hulisz, D. Efficacy of Zinc Against Common Cold Viruses: An Overview. JAPhA[5]. 2004; 44: 594-603. Available at: http://mw8xt6bj7r.search.serialssolutions.com/?genre=article&issn=15443191&title=Journal+Of+The+American+Pharmacists+Association%3a+Japha&volume=44&issue=5&date=20040901&atitle=Efficacy+of+zinc+against+common+cold+viruses%3a+an+overview.&spage=594&pages=&sid=EBSCO:MEDLINE&aulast=Hulisz+D . Accessed April 13, 2009. • [5] Eby G, Halcomb W. Ineffectiveness of Zinc Gluconate Nasal Spray and Zinc Orotate Lozenges in Common-cold Treatment: A Double-Blind, Placebo-controlled Clinical Trial. Alternative Therapies. Jan/Feb 2006; 12: 34-37. Available at: http://web.ebscohost.com/ehost/detail?vid=4&hid=115&sid=718a55e6-1b33-41d9-95b0-bb2d6f136b39%40SRCSM2&bdata=JmxvZ2lucGFnZT1Mb2dpbi5hc3Amc2l0ZT1laG9zdC1saXZl#db=cmedm&AN=16454145. Accessed April 8, 2009. • [6] Kurugol Z, Akilli M, Bayram N, Koturoglu G. The Prophylactic and therapeutic effectiveness of zinc sulphate on common cold in children. ActaPaediatrica. 2006; 95: 1175-1181. Available at: http://web.ebscohost.com/ehost/detail?vid=9&hid=2&sid=718a55e6-1b33-41d9-95b0-bb2d6f136b39%40SRCSM2&bdata=JmxvZ2lucGFnZT1Mb2dpbi5hc3Amc2l0ZT1laG9zdC1saXZl#db=cmedm&AN=16982486. Accessed April 8, 2009.

26. The End!