Zinc and the Common Cold

There’s a reason why the common cold is called, well, the “common” cold. On average, adults in the United States must slog through two to four yearly colds. For children, the number is six to ten. Moreover, the Centers for Disease Control and Prevention notes that colds lead to numerous missed school days, to the tune of 22 million school days every year. Considering this information, it isn’t surprising that some estimates have found that Americans contract 1 billion colds annually.

Since the common cold remains a thorn in the side of the American public, medical researchers have continued to study methods of preventing and treating this illness. In keeping with this goal, a recent report examined the effectiveness of numerous cold remedies. Published in the February 18^th, 2014 issue of the Canadian Medical Association Journal (CMAJ), the authors of this research reviewed a total of 67 previous studies.

Comparing Probiotics, Vitamin C and Zinc

Probiotics have garnered much attention in the last several years. Found in both foods and in certain supplements, probiotics are defined by the World Health Organization as “live micro-organisms which when administered in adequate amounts confer a health benefit on the host.” A fair amount of research has supported the idea that probiotics are beneficial to digestive health.

The study published in the CMAJ examined the impact of probiotics on colds, and unearthed some evidence that these substances may boost the body’s defenses against respiratory cold infections. Unfortunately, the data regarding the relationship between the two was contradictory. Furthermore, vitamin C was determined to be ineffective in fending off cold-causing viruses.

The story was quite different regarding zinc, a mineral used by the body to divide cells and make proteins. According to the report, two randomized trials found that zinc could offer some protection for children against colds. In contrast to subjects who were given placebos, children who took zinc during these trials experienced fewer colds and school absences. They also consumed fewer antibiotic medications.

Randomized controlled trials, like those used in the aforementioned studies, are generally considered to be very potent research tools. During such trials, subjects are usually given some sort of treatment, while another group of participants may receive a placebo that has no physical effect on the body. These substances are distributed on an arbitrary basis.

A 2014 Indian study likewise found that zinc could be a useful weapon against colds. Children were less likely to catch cold if they took zinc as a preventative measure over a five month span. Moreover, taking zinc supplements within the first 24 hours of a cold was found to speed up a patient’s recovery. These findings did come with some asterisks attached; the authors stated that “given the high heterogeneity of data, these results should be interpreted with caution” and that “the prevalence of adverse effects with zinc lozenges is high.” In addition, the research team also cautioned against using zinc as a preventative measure over an extended period of time.

The Other Contenders

In addition to zinc, vitamin C and probiotics, the studies examined by the research team also looked at other ways of fighting colds:

Over the Counter Cough Medicine – Adult subjects experienced some relief from these medicines, but this response was not observed in children.

Gargling Water – Some people make the claim that gargling with water does a number on cold viruses. To be sure, one report did in find that gargling might be helpful to cold sufferers, though the authors believe that a second study is necessary to confirm these benefits.

Washing Hands/Using Disinfectants – Here’s another reason to practice proper hygiene – in most of the studies reviewed by the researchers, both hand washing and disinfectant use helped shield subjects from colds.

Antihistamines and Decongestants – Taken in combination, these medicines likely helped both adults and older children bounce back from cold viruses. Despite this finding, the research team discouraged giving children aged 5 and younger both medications simultaneously.

Honey – Surprising as it may sound, eating a single spoonful of honey not only lessened coughing symptoms in children, but also made it easier for them to fall asleep.