In addition to structuring human proteins, this metal is necessary for enzymatic functioning and many other compounds.
Zinc has been known for many years for its antiviral effect against the rhinovirus - cold virus - found mainly in the laboratory.
Zinc is normally taken with food but it is possible to increase its intake through supplements. The Recommended Intake for the Population (PRI) and / or Adequate Intake (AI) of zinc ranges from 5 mg / day to 12 mg / day , depending on sex and age.
These have a different effect depending on the therapeutic objective. For the treatment of colds, zinc - or rather its ionic derivatives - are administered in tablets to be sucked and dissolved in the oral cavity.
Research on the "effect of zinc on colds began in 1984 and continues today." The differences in the experimental results, which we will analyze later, may be due in part to differences in the constituents of the tablets.
of humans - is the statistically predominant cause of the common cold. It is hypothesized that the mechanism of action by which zinc can reduce the severity and / or duration of cold symptoms includes:
- Suppression of nasal inflammation
- Direct inhibition of the link between the rhinovirus and the receptor
- Inhibition of rhinovirus replication in the nasal mucosa.
Note: The pharmaceutical forms used for zinc-based supplements are sucking tablets.
with zinc they were less likely to have symptoms remaining beyond 7 days after the onset of the disease.
A 2015 meta-analysis found no differences in symptoms of common cold patients treated with acetate-type zinc. Although these "candies" work by increasing the concentration of zinc in the oral cavity, continuing to increase the concentration would not result in a proportional improvement in efficacy. In general, in this study, the duration of nasal discharge was reduced by 34%, congestion 37% nasal, 22% sneezing, 33% throat irritation, 18% sore throat, 43% hoarseness and 46% cough. Zinc tablets reduced the duration of muscle pain by 54%, but there was no significant effect on the duration of the headache and fever.
A 2016 meta-analysis of zinc acetate for the treatment of the common cold found that symptoms were 2.7 days shorter than an average duration of 7 days.
A 2017 work on zinc-acetate lozenges showed that regardless of age, gender, ethnicity, allergy, smoking and severity, these can promote the remission of the common cold symptoms faster - 70% vs 27% - than normal. - ratio of 3: 1.
The 2017 meta-analysis compared high-dose zinc acetate tablets (> 75 mg / day of elemental zinc) with zinc gluconate tablets and found no difference in efficacy. Furthermore, there was no evidence. significant that zinc doses> 100 mg / day are more effective than those equal to 80-92 mg / day.
However, due to the lack of data, there is insufficient evidence to determine whether preventive use of zinc supplements can reduce the likelihood of contracting the common cold. Furthermore, the effects of zinc supplementation on duration and severity of cold symptoms in people with AIDS / HIV or chronic illness are not known, due to the lack of highly specific studies.
unpleasant, but none of the insights reported any long-term damage. Furthermore, many of the adverse effects, particularly with regard to taste, may be caused by the specific composition of the candies to be sucked - see excipients - and probably do not reflect the impact of the zinc ions contained in them. For example, gluconate of zinc with dextrose (glucose) worsens from the gustatory point of view only after a few weeks from manufacture; those based on zinc acetate dihydrate, on the other hand, mixed with dextrose 1: 100, should not have this complication. "zinc acetate - a daily dose of 92 mg of the mineral - did not show significant differences with placebo.
There have been several cases of people experiencing loss of smell when using zinc-based nasal sprays. In 2009, the US Food and Drug Administration specified that people should not use zinc-containing nasal sprays.
common cold - The Cochrane Database of Systematic Reviews: CD001364
