Zinc is a mineral with a host of roles in the human body, from supporting fertility and proper growth and development to boosting immune function. A deficiency of zinc can make the body more prone to infections. In developing countries where deficiencies of the nutrient are more common, supplementing with zinc helps prevent the common cold, diarrhea, and pneumonia in children.
Fact or fiction?
Some people maintain that zinc lozenges help keep their colds in check, but skeptics argue that evidence for their use is lacking.
In an attempt to sort out the confusion over whether zinc can really help clear up the common cold more quickly, investigators from the Department of Public Health at the University of Helsinki, Finland conducted a review of studies published on the topic.
Thirteen trials were included in the analysis:
- five trials used zinc lozenges providing less than 75 mg of elemental zinc per day, and
- eight studies used lozenges that provided more than 75 mg of zinc per day; three used zinc acetate, and five used other forms of zinc.
None of the studies using less than 75 mg of zinc per day had an effect on the duration of the common cold. However, in seven of the eight studies using more than 75 mg of zinc per day, cold durations were significantly shorter.
Zinc acetate seemed to have the most profound effect on shortening the common cold, with a 42% reduction in the number of sick days. Other forms of zinc lozenges also helped people get better faster, shortening the duration of the cold by 20%.
Some people don't like the taste of zinc lozenges and others may develop nausea from them, but there have not been reports of long-term side effects associated with their use. "More research is needed on zinc lozenges to find optimal lozenge compositions and treatment strategies," commented the study's authors.
Best bets for cold season
When you feel the familiar signals of an impending cold, try these tips to nip it in the bud for a faster return to your healthy self.
- Moisturize your insides. Viruses like the ones that cause the common cold thrive in dry environments. Dry air also takes a toll on the mucous membranes, worsening a sore throat and nasal congestion. Use a vaporizer or humidifier to add moisture to the air, but make sure to clean it regularly and use new water each day. Also, keep up the fluids to breathe easier and prevent dehydration.
- Give zinc lozenges a try. Look for zinc acetate and aim for a total of at least 75 mg per day.
- Enjoy a bowl of chicken soup. Grandma's remedy has stood up to the rigors of scientific investigation, with solid evidence to support the use of chicken soup in treating the common cold. When it's loaded with veggies, chicken soup seems to decrease inflammation and ease cold symptoms.
- Boost your C. Taking 500 mg of vitamin C three times per day at the start of a cold may reduce the duration of illness.
(Open Respir Med J 2011;5:51-8.)