Q. A few friends have mentioned that taking zinc helps to ward off colds and flu. Is there any validity to that?
A. The evidence on zinc is inconclusive. There have been more than more than 10 well-controlled trials of zinc lozenges, nasal sprays or gels. Although some have shown benefit, others did not show that zinc is better than placebo. We need better research before we can give you a definite answer.
