Zinc and the Common Cold

Zinc preparations have been becoming increasingly popular for treating common cold symptoms.  I’ve been skeptical about their usefulness, at least until a year or so ago, when a study appeared suggesting they could shorten the duration of symptoms by about half a day.  Even then, this didn’t seem interesting enough for me to embrace their use.  But that may change with the publication of a recent Cochrane Review of published clinical studies. 

The review covered 13 placebo-controlled trials involving almost 1,000 subjects.  Zinc intake reduced the duration of cold symptoms by nearly a day when taken within 24 hours of the first symptoms.  It also eased the severity of symptoms, significantly, and reduced the proportion of subjects who were still symptomatic after 7 days by almost half. 

There were also two preventive trials with almost 400 participants who took zinc products for at least 5 months.  The likelihood of developing a cold in the zinc-taking subjects was reduced to about 64% of the likelihood for the non-zinc subjects, along with significantly fewer absences from schools and antibiotic prescriptions with zinc.

Side effects were mild – there were more complaints of bad taste and nausea in those taking zinc lozenges than in those on a placebo.

It looks as if zinc can be used for its beneficial actions in mitigating cold symptoms.  However, a firm recommendation cannot be made until more is known of the best formulation, dose level, frequency of dosage, etc., and whether there may be problems when zinc is given to subjects with underlying conditions, such as COPD, asthma, and so on.  Still, if you’re healthy and feel a cold has started, why not try it?  You may be a “responder”!