Last week I wrote about the role that vitamin C may have in the treatment of cancer.
Of course, vitamin C may have other potential benefits. In high doses, vitamin C is sometimes said to be a useful remedy for the common cold. Another nutrient that has some reputation for potential benefit in treating colds is zinc.
In natural medicine, it is sometimes recommended that the individual suck zinc lozenges to hasten healing from the common cold. There is indeed some evidence to suggest that there is merit in this approach, which dates back more than 20 years.
I was interested to read about another study, this one published earlier this year, in which zinc lozenges were tried by individuals with the common cold. Here, zinc acetate lozenges (13.3 mg of zinc acetate per lozenge) were used (previous studies have tended to use zinc gluconate or zinc acetate). Individuals were randomized to suck on zinc lozenges or placebo lozenges every two to three hours while awake, starting within a day of developing cold symptoms.
Compared to the individuals taking placebo lozenges, those taking zinc lozenges:
• Had cough symptoms for a shorter period of time (2.1 days versus 5 days)
• Had nasal discharge for a shorter period of time (3 days versus 4.5 days)
• Overall, had cold symptoms for a shorter period of time (4 days versus 7.1 days)
Symptom-severity scores were lower in the zinc-lozenge-taking group, too.
The authors of this study put the therapeutic properties of zinc in this context down to the mineral’s antioxidant and anti-inflammatory properties. However, it may also be that zinc can exert benefits through an ability to inhibit the common cold virus (rhinovirus) [3], as well as through some ability to affect the immune response.
However they work, there is now quite a body of evidence that suggests that zinc lozenges have real value in the treatment of the common cold.
References:
1. Eby GA, et al. Reduction in duration of common colds by zinc gluconate lozenges in a double-blind study. Antimicrobial Agents and Chemotherapy 1984; 25:20-24
2. Prasad AS, et al. 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. Journal of Infectious Diseases 2008; 197(6): 795-802
3. Korant BD, et al. Inhibition by zinc of rhinovirus protein cleavage: interaction of zinc with capsid polypeptides. Journal of Virology 1976; 18(1): 298-306.
Dr. John Briffa is a London-based physician and author with an interest in nutrition and natural medicine.
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