People have been searching for a cure for the common cold for centuries. To date there is nothing that actually overcomes cold viruses the way antibiotics conquer bacteria.That said, there are dozens of remedies on drugstore shelves purported to soothe symptoms and speed healing. One that has become popular and controversial over the last few decades is zinc. Some studies suggest that this mineral helps while others demonstrate little benefit.
Now experts for the highly respected international Cochrane Collaboration have examined all the evidence from 15 trials and concluded that zinc does seem to shorten cold duration by about a day. There was some evidence that zinc can help prevent colds in healthy people, but the researchers don’t have enough data to recommend a dosing regimen. Zinc works best if taken within 24 hours of the first cold symptoms.
[Cochrane Database of Systematic Reviews, 2011, Vol. 2]