According to a systematic review, zinc lozenges lessen the severity as well as length of time of illness as a result of the common cold. The results may help cut down the number of days lost from school and work because of colds.[1]
A heavy burden is placed on society by the common cold, accounting for as much as 40 percent of time away from work and countless days of school skipped by kids every year. The theory that zinc could be effective for the common cold originated from research performed in 1984, which revealed that zinc lozenges can reduce the length of time symptoms lasted. After that study, research has produced inconsistent results and although a number of arguments for the effect have been suggested, none of them have been proven.
This review updates a previous review conducted in 1999, along with data from a number of new studies. Altogether, data from 15 studies involving 1,360 individuals were included. The results suggest that zinc lozenges or syrup taken within 1 day of the start of cold symptoms lessen the severity as well as duration of illness. At 7 days, more of the individuals who had taken zinc lozenges had eliminated their symptoms in comparison to individuals who had taken placebos. Kids who had taken zinc lozenges or zinc syrup for 5 months or more caught a lesser number of colds and took fewer days off school. The use of antibiotics in kids was also reduced, which is important as excessive use has implications for resistance of antibiotics.
Although the review supports the evidence for zinc as a remedy for the common cold, it’s still tough to make a broad recommendation, considering that not much is known about the ideal dose, formulation or duration of treatment.