"Taking zinc either as a syrup or lozenge through the first few days of a cold may shorten the misery of an upper respiratory infection a new research review shows. The review also found that zinc cut the number of days that kids missed school because of being sick and reduced the use of antibiotics https by cold sufferers. It also appeared to prevent colds https in people who used it over the course of about five months. This is great news says Kay Dickersin PhD an epidemiologist with the Johns Hopkins School of Public Health and director of the U.S. Cochrane Center. We really dont have interventions for colds https that work. The review of  studies with  participants was published by the Cochrane group an international collaboration of researchers that reviews evidence behind therapeutic interventions. It updates a  Cochrane review that found no strong evidence to recommend zinc as a help for colds https The evidence from the recent trials does support the use of zinc lozenges in treatment of common cold https says study researcher Meenu Singh MD a pediatric pulmonologist at the Post Graduate Institute of Medical Research in Chandigarh India. Zinc vs. Placebo A total of  trials pitted zinc against a placebo https in people under age  suffering from early cold symptoms https_coldsymptoms including sore throats headaches https coughs https fever runny or stuffy noses sneezing https hoarseness and muscle aches. When taken within the first  hours of symptoms results from six trials showed that using zinc lozenges or syrup appeared to shorten the duration of a cold by about a day. Results from five studies representing more than  people showed that those using zinc had less severe symptoms compared to those taking a placebo. An analysis of two combined studies representing more than  people found about  fewer colds in those who were taking zinc supplements https to prevent colds compared to those taking a placebo. Side effects reported by zinc users included nausea https and a bad or metallic taste https in the mouth https While the news is promising the study stopped short of making recommendations based on its findings saying that there was still not enough evidence to give people guidance on what kind of zinc to use how much to take or how long to use it. How Zinc Fights Colds Zinc appears to work in two ways says Ananda Prasad MD PhD a professor of internal medicine at Wayne State University School of Medicine in Detroit who has spent his career researching zincs effects on the immune system. First zinc interferes with the ability of rhinoviruses which are responsible for about  of all colds to reproduce. Second it appears to block their ability to dock on cell membranes and subsequently cause infection. Prasad published a study in  in the Journal of Infectious Diseases which tested zinc lozenges against placebo in  study participants. Half got . milligrams of zinc every  hours in a zinc acetate lozenge the other half got a dissolvable wafer with inactive ingredients that tasted the same. Usually it takes about eight days for a cold to disappear Prasad says but with zinc it cuts down by about . Study participants who took zinc got over their colds in about four days compared to seven days in the group that got the placebo. If you consider how many people lose their days of work because of the common cold https its astounding Prasad says. In children and the elderly the incidence of colds is six to seven a year. The news that zinc could make a dent in some of that misery when not much else does is exciting Prasad thinks. So far to my knowledge theres nothing else thats effective he says. Experts stress that more research is needed before the most effective kind of zinc can be determined and they caution that in high doses  more than  milligrams per day  zinc can cause dizziness https headache https drowsiness increased sweating https loss of muscle coordination alcohol intolerance hallucinations https and anemia https They also warn against using zinc nasal sprays which some reports suggest can cause loss of smell or from using nasal swabs."