Reduction in duration of common colds by zinc gluconate lozenges in a double-blind study

Abstract

As a possible treatment for common colds, we tested zinc gluconate lozenges in a double-blind, placebocontrolled, clinical trial. One 23-mg zinc lozenge or matched placebo was dissolved in the mouth every 2 wakeful h after an initial double dose. After 7 days, 86% of 37 zinc-treated subjects were asymptomatic, compared with only 46% of 28 placebo-treated subjects (P = 0.0005). Side effects or complaints were usually minor and consisted mainly of objectionable taste and mouth irritation. Zinc lozenges shortened the average duration of common colds by about 7 days.

Zinc Gluconate and the Common Cold: A Controlled Clinical Study

“…Even with the recognition that placebo in the present study was not entirely devoid of activity, there was a significant (P< 0.025) reduction in the severity of symptoms in the ZGG treatment group compared with placebo at day 7; day 7 has been commonly used for comparison in other published studies that include duration and symptom severity data. 1,2,15 The effects observed in the present study indicate that there may be a 1 -2 day 'window of opportunity' for treatment with ZGG before the common cold takes hold. It could be determined from further studies whether cold symptoms would last an even shorter time if ZGG treatment were begun on the day of symptom onset.…”

“…This is further suggested by another study, which found a significant reduction of symptoms when a non-chelating formulation was used. 7 The present study was carried out to test the hypothesis that pleasant-tasting ZGG lozenges that release 93% of the ionic zinc into saliva may produce similar efficacy to that originally reported by Eby et al 1 …”

“…Attempts made to duplicate the success which Eby et al 1 had in 1984 in reducing the duration of the common cold using zinc gluconate have generally been disappointing, [2][3][4] the probable reason being that zinc gluconate was inactivated by additives used to mask its unpleasant taste. It has been demonstrated that of these agents, e.g.…”

The mouth–nose biologically closed electric circuit in zinc lozenge therapy of common colds as explanation of rapid therapeutic action

“…The immuno logical mechanisms of action of zinc that they cited appear correct and it is also true that they are of a delayed nature. However, they probably cannot alone account for the rapid therapeutic action of strong zinc lozenges in aborting colds as was first reported by Eby et al [2] and elsewhere. The fact that the first observation of the rapid action of zinc lozenges against colds occurred in a child with T-cell leukemia and with no functional immune system due to chemotherapy is a good indicator that more is involved [2].…”

“…However, they probably cannot alone account for the rapid therapeutic action of strong zinc lozenges in aborting colds as was first reported by Eby et al [2] and elsewhere. The fact that the first observation of the rapid action of zinc lozenges against colds occurred in a child with T-cell leukemia and with no functional immune system due to chemotherapy is a good indicator that more is involved [2]. There is a local mechanism of action: the mouth-nose biologically closed electric circuit (BCEC) [3,4], which appears to explain the rapid therapeutic response to zinc lozenges.…”