Zinc Lozenges Reduce Duration of Common Cold
Lee Swanson Research Update
There may be no cure for the common cold, but studies show zinc lozenges can help you recover more quickly. Rhinovirus infections of the upper respiratory tract (aka the common cold) are among the world’s most widespread illnesses and a leading cause of doctor visits and absences from school and work. Although it is not typically considered a serious illness, the common cold has a serious economic impact resulting from lost productivity in addition to the burden of human suffering inflicted by cold symptoms.
In light of zinc’s demonstrated ability to inhibit replication of the rhinovirus, there have been numerous trials over the past 30 years investigating the potential of supplemental zinc to reduce the duration and severity of cold symptoms. The results of these trials have been inconsistent, due in large part to variations in dosages and forms of zinc supplements used. To evaluate the efficacy of zinc in treating common cold symptoms based on the best scientific evidence available, the Cochrane Database of Systemic Reviews conducted an analysis of eighteen placebo-controlled clinical trials involving 1,781 subjects.
While the studies included in the review varied in duration, dose and formulation of zinc used, zinc lozenges were the form used most often. When administered within the first 24 hours of the onset of cold symptoms, zinc lozenges at intakes of 75 mg or more per day were associated with a significant reduction in duration—but not severity—of cold symptoms, reducing the average duration of cold symptoms by slightly more than a day compared to placebo. In the more stubborn cases, subjects taking zinc were significantly less likely to have symptoms lasting more than seven days compared to subjects taking a placebo. The study authors note that “for those considering using zinc it would be best to use it at this [75 mg/day] dose throughout the cold.”
Singh M, Das RR. Zinc for the common cold. Cochrane Database of Systematic Reviews 2013, Issue 6. Art. No.: CD001364. doi: 10.1002/14651858.CD001364.pub4. Published Online: 18 JUN 2013