Zinc supplements break grip of common cold
25 February 2011
Zinc supplements can reduce the length and severity of the common cold in adults and children, a Cochrane review shows (Cochrane Database Syst Rev 2011; 2: CD001364).
(Cochrane reviews are conducted by the Cochrane Collaboration, an international organisation aimed at helping people make well-informed decisions about healthcare by undertaking scientific reviews of evidence for certain treatments.)
The review of 15 randomised trials showed zinc – taken as syrup, lozenges or tablets – needs to be administered within 24 hours of the start of symptoms to be effective.
In addition to reducing the length and severity of colds, zinc supplements also led to fewer colds, reduced school absences, and decreased antibiotic use in children when used for prevention over 5 months.
However, side effects of zinc supplements were common. Eleven trials reported bad taste, nausea, constipation, diarrhoea, abdominal pain, dry mouth or irritation.
Dosage regimens varied, with side effects more likely to be reported by those taking lozenges, the reviewers said.
In 10 trials reporting the duration of cold, 6 results could be pooled to show a significant reduction in cold duration, on average 42 per cent.
Of these, 2 trials used a daily dose of 30 mg of zinc syrup, whereas the remaining 4 trials used zinc lozenges at daily doses of 90 to 160 mg, the reviewers said.
In 2 trials showing favourable results for zinc as prevention, one used a daily 15 mg dose of zinc sulfate syrup for 7 months and another used 10 mg zinc sulfate tablets for 5 months.
Last Reviewed: 28 February 2011
- 1. Singh M, Das RR. Zinc for the common cold. Cochrane Database Syst Rev 2011; 2: CD001364. doi: 10.1002/14651858.CD001364.pub3. http://onlinelibrary.wiley.com/o/cochrane/clsysrev/articles/CD001364/frame.html (accessed Feb 2011).
