Zinc for colds
You’ve probably heard a lot about zinc for colds, but is zinc really effective for reducing the duration of cold symptoms? Colds account for millions of days off work and school each year. Here’s what you should know about zinc and colds.
What is zinc?
Zinc is an essential mineral that is found in almost every cell. Zinc has antioxidant effects and is vital for the body’s resistance to infection. It may also decrease the ability of cold viruses to grow on or bind to the lining of the nose, and zinc is important for tissue repair.
Zinc is found naturally in shellfish, beef and other red meats, nuts and seeds, beans, and milk and cheese. Tea, coffee and certain medications may interfere with zinc absorption in the intestines.
Over-the-counter preparations are sold as the mineral zinc combined with gluconate, sulphate or acetate.
Is zinc an effective cold remedy?
Researchers have studied the use of zinc as a cold remedy and as a way to treat the cold virus. Still, the data from years of scientific studies are mixed.
A 2011 review of evidence from 15 published studies involving 1,360 people in the Cochrane Library found that zinc supplements reduced the duration and severity of illness caused by the common cold.
However, the researchers said it was still not possible to make any general recommendations about treating colds with zinc, because more information was needed about the optimum dose, formulation and length of treatment.
Another review of evidence from other studies in 2012 in the Canadian Medical Association Journal also found that that taking zinc tablets may shorten the duration of a cold.
The research reviewed 14 studies involving 2,121 people.
People taking zinc had cold symptoms for an average of between one to two days less than people given a dummy or placebo treatment.
Higher doses of zinc seemed to reduce the duration of symptom better than low doses. However, zinc did not seem to help shorten colds in children.
Large high quality trials would be needed to check whether the benefits of zinc outweigh side effects.