Study on the Effects of Zinc Lozenges on Colds
One analysis comparing placebo to oral zinc products in 17 different patient trials showed that the duration of the cold was shortened by two days. However, Dr. Micheller Science, lead author, who is also a specialist of infectious disease at the Hospital for Sick Children in Toronto, stated an analysis of trials that had over 2,100 patients had no results as far as zinc relieving how severe the symptoms became with the colds.
Basically, the researchers discovered that is zinc was taken orally at the beginning of the cold it reduced how long the person would suffer from symptoms as in congestion or a runny nose according to Science.
He went on to say, "But the reduction was relatively minor, so less than two days on average was what we found. If the average cold lasts seven to 10 days, then take off perhaps on average a day and a half of symptoms."
There were some results that showed by taking zinc adults were less at risk for having symptoms last past 7 days, even though there was not a difference with the symptoms between the test groups at the point of 3 days.
Over 100 viruses are known to bring on the common cold. This could leave people with runny noses, sore throats, difficulty breathing, sneezing, fatigue, headaches and coughing. Children have fevers more than adults do. Symptoms can last from 7 to 14 days.
Zinc showed no signs of helping kids get rid of a cold sooner. Several clinical trials were done with meta-analysis, which looks at a number of studies instead of drawing conclusions from just one and these found that children do not get relief from taking zinc compared to a placebo.
According to Science, one explanation for this difference is that most kids involved in these studies received zinc syrup two time per day, which was a much lower dosage proportionately than what the adults took each day. She goes onto say zinc has a localized effect. So that syrup swallowed at one time may not be as effective as a zinc lozenge slowly dissolved over a period of time. The adults typically had one lozenge at two-hour intervals through the day up to a limit of 8 in a day. Also, what time of the year the studies are conducted could influence the outcome, because different viruses could be causing the colds.
Some children studies in the northern hemisphere were held in the winters, so these kids might have had the respiratory syncytial virus that can cause infections in the upper respiratory systems similar to a cold.
The adults on the other hand were studied all through the year. Rhinoviruses were likely to have caused their colds as these viruses do cause half the colds that happen. Zinc shows some favorable results in combating rhinoviruses in earlier laboratory studies.
A recently published study in Canadian Medical Association discovered that not all formulations of zinc are created equal. The zinc acetate is more effective than zinc sulphate or zinc gluconate.
According to Dr. Samira Mubareka from Toronto, the idea of taking zinc for colds dates back to the 1970s, when research was done on rhinoviruses and zinc. This has just stuck with people and it could be an affordable supplement to relieve a cold.
However, the individual trials have had too few people to come to solid conclusions standing alone. Even though the meta-analysis provides stronger results with its numbers, researchers still say the results are not the proof that zinc helps get rid of colds.
Mubareka still thinks that zinc has potential and that more studies need to be performed to get conclusive proof, even though she would not start taking zinc or prescribing it for patients until more research is done.