Study Examines Zinc’s Role In Soothing The Common Cold
May 8, 2012

Study Examines Zinc’s Role In Soothing The Common Cold

Connie K. Ho for

The symptoms of the common cold can run the gamut. There´s the runny, stuffy nose and itchy, sore throat with a cough. Then there´s the feeling of fatigue and slight body aches. To top it off, having a cold can give you the sensation of watery eyes and a mild headache. A new study by Canadian researchers targets common cold symptoms and has found that oral zinc treatments could possibly decrease the length of symptoms of the common cold in adults; however, the study found that adverse effects generally result from the treatment.

The research was published in the Canadian Medical Association Journal (CMAJ). CMAJ highlights medical research that impacts Canadians and others on a global basis. Over the last 101 years, the journal has focused on raising awareness regarding health issues, covering the connection between sun exposure and skin cancer, abortion, contraception, among other topics.

The study included an examination of 17 randomized controlled experiments with 2,121 participants between one and 65 years of age. The group wanted to see the effectiveness and safety of using zinc to treat the common cold, utilizing trials that were double-blinded and placebos. According to the Mayo Clinic, zinc is commonly used by the body for normal growth and health. Zinc can be found in items such as beans, peas, lean red meats, seafood, whole grains, and other foods.

The researchers found that, compared to the placebo, the zinc treatments shortened the duration of the cold symptoms. The higher the dosage of zinc, the more effective it was at shortening the duration of the cold symptoms. However, the team noted that the study yielded a mix of results.

"We found that orally administered zinc shortened the duration of cold symptoms," remarked Dr. Michelle Science of the Hospital for Sick Children (SickKids), a pediatric health-care center focused on the integration of areas like research and education with patient care, along with coauthors at McMaster University."These findings, however, are tempered by significant heterogeneity and quality of evidence."

The study showed that the zinc treatment was more effective in adults than it was in children. It was also more effective when the zinc was taken regularly. Side effects of the zinc treatment included bad taste and nausea. The project by the Canadian researchers differed from previous studies, where zinc has had conflicting effects in decreasing the severity of cold symptoms and the length of time of the cold symptoms.

"Until further evidence becomes available, there is only a weak rationale for physicians to recommend zinc for the treatment of the common cold," wrote the authors in the report. "The questionable benefits must be balanced against the potential adverse effects."

According to Med Page Today, other limitations in the project included the fact that the studies were done in developed countries and funded by industry-related groups. The assumptions in the project were also designed to calculate means and standard deviations of many of the trial estimates. Lastly, ineffective blinding associated with the taste of the placebo may have also affected the trials and created some bias.