Scams and pseudoscience are not altogether uncommon in alternative medicine, so practitioners and medical establishments tend to automatically dismiss popular home remedies as soon as a single study calls their safety or efficacy into question. It's no surprise that, after a few studies with negative results, zinc supplements to treat the common cold lost favor among consumers and practitioners. However, a recent comprehensive review has supported the use of this once-popular remedy, suggesting that we should give zinc supplements another try.
The review, spearheaded by the Canadian Medical Association, looked at the results of seventeen independent studies comparing the results of zinc supplements to placebos for the treatment of the common cold. Altogether, the studies included 2,121 participants across all major age groups, and investigated the effects of varying doses. These comprehensive reviews are more reliable than single studies because they examine larger groups and eliminate the risk of publication bias.
The scientists determined that zinc is indeed worth a second look as a treatment for the common cold. Compared to patients taking a placebo, patients taking zinc supplements had a shorter duration of cold symptoms. The results were statistically significant, meaning that errors, coincidences, and inaccuracies were unlikely to cause these results. Interestingly, though, scientists only documented these effects in adults; children in these studies did not show statistically significant differences in the duration of cold symptoms.
Of course, the Canadian Medical Association is hesitant about making a strong recommendation at this point. Even a broad, comprehensive review isn't enough to definitively prove that zinc is effective, even though the results are currently promising. Also, zinc frequently causes mild side effects, including nausea and bad taste. Given that the common cold is usually very mild, it may not be worth these side effects for all patients. In time, further studies may help to validate the use of zinc and other nutritional treatments for the common cold.
Juniper Russo is a freelance writer, health advocate, and dedicated mom living in Chattanooga, Tenn.