"Scientists still havent discovered a cure for the common cold httpshealth.nytimes.comhealthguidesdiseasecommoncoldoverview.htmlinlinenytclassifier but researchers now say zinc httpshealth.nytimes.comhealthguidespoisonzincoverview.htmlinlinenytclassifier may be the next best thing. A sweeping new review of the medical research on zinc shows that sniffing sneezing httpshealth.nytimes.comhealthguidessymptomssneezingoverview.htmlinlinenytclassifier coughing and stuffyheaded cold sufferers finally have a better option than just tissue and chicken soup. When taken within  hours of the first runny nose httpshealth.nytimes.comhealthguidessymptomsnasaldischargeoverview.htmlinlinenytclassifier or sore throat httpshealth.nytimes.comhealthguidessymptomssorethroatoverview.htmlinlinenytclassifier zinc lozenges tablets or syrups can cut colds httpshealth.nytimes.comhealthguidesdiseasecommoncoldoverview.htmlinlinenytclassifier short by an average of a day or more and sharply reduce the severity of symptoms according to the Cochrane Database of Systematic Reviews https a respected medical clearinghouse. In some of the cited studies the benefits of zinc were significant. A March  report https in The Journal of Infectious Diseases for example found that zinc lozenges cut the duration of colds to four days from seven days and reduced coughing to two days from five. While the findings are certain to send droves of miserable cold sufferers to the drugstore in search of zinc treatments the study authors offered no guidance on what type of zinc product to buy. The authors declined to make recommendations about the optimal dose formulation or duration of zinc use saying that more work was needed before they could make recommendations. Over all it appears that zinc does have an effect in controlling the common cold said Dr. Meenu Singh the reviews lead author and a professor in the department of pediatrics httpstopics.nytimes.comtopnewshealthdiseasesconditionsandhealthtopicspediatricsindex.htmlinlinenytclassifier at the Postgraduate Institute of Medical Education and Research in Chandigarh India. But there still needs to be consensus about the dose. Zinc experts say that many overthecounter zinc products may not be as effective as those studied by researchers because commercial lozenges and syrups often are made with different formulations of zinc and various flavors and binders that can alter the effectiveness of the treatment. A lot of preparations have added so many things that they arent releasing zinc properly said Dr. Ananda Prasad professor in the department of oncology at Wayne State University School of Medicine in Detroit and an early pioneer of research into zinc as an essential mineral. Two of Dr. Prasads studies were included in the Cochrane report. The public is confused because people have used the wrong dose they have used the wrong sort of zinc or they have not started the treatment within  hours of onset he said. Even so the new report gives credence to the longdebated theory that zinc can be an effective treatment for colds. While its not certain how the mineral curbs colds it appears to have antiviral properties that prevent the cold virus from replicating or attaching to nasal membranes. The first study to show that zinc might be a useful treatment for the common cold was published in  but the research was criticized for its poor methods. Since that study  more trials of zinc for colds have been conducted  of them showed it to be a useful treatment while seven of them showed no benefit according to the review. Although a majority of trials have shown some benefit from zinc many of them have been criticized for failing to mask the treatment meaning the participants most likely knew they were using zinc which may have skewed the results. At the same time many of the trials that showed no benefit from zinc have been criticized for using formulations that may have contained ingredients that blunted the effectiveness of zinc. The Cochrane reviewers selected  studies that enrolled a combined  participants. The studies were all considered to have good methodological quality with a low risk of bias but they were far from perfect. All the studies compared zinc use with a placebo but in several studies the zinc users complained about the taste of lozenges suggesting that some people may have known that they were using zinc rather than a placebo. Even so when the data was pooled the effect shown was strong. The review found that not only did zinc reduce the duration and severity of common cold symptoms but regular zinc use also worked to prevent colds leading to fewer school absences and less antibiotic httpstopics.nytimes.comtopnewshealthdiseasesconditionsandhealthtopicsantibioticsindex.htmlinlinenytclassifier use in children. People who used zinc were also far less likely to have a cold that lasted more than seven days. The studies used various forms and doses of zinc including zinc gluconate or zinc acetate lozenges and zinc sulfate syrup and the dose ranged from  to  milligrams a day. Several studies in the Cochrane review used zinc acetate lozenges from the Web site ColdCure.com httpscoldcure.com created by George Eby the researcher who wrote the first zinc study in . Dr. Prasad said his studies have used zinc acetate lozenges from ColdCure.com that contained about  milligrams of zinc. Study participants took a lozenge every three to four hours during the day for four consecutive days resulting in a daily dose of  to  milligrams a day he said. Some cold sufferers have been wary about using zinc since the Food and Drug Administration httpstopics.nytimes.comtopreferencetimestopicsorganizationsffood_and_drug_administrationindex.htmlinlinenytorg warned consumers to stop using Zicam nasal sprays and swabs which contain zinc after numerous reports that some users lost their sense of smell after using the product. The Cochrane report did not review any studies of nasal zinc products."