Zinc for Colds: Lozenges & Nasal Sprays
You’ve probably heard a lot about zinc for colds. But is zinc really effective for reducing the duration of cold symptoms? 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. It has antioxidant effects and is vital to the body’s resistance to infection. Zinc is also important for tissue repair. It may decrease the ability of cold viruses to grow on or bind to the lining of the nose.
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 complexed with gluconate, sulfate, or acetate.
Is Zinc an Effective Cold Remedy?
Researchers have studied the use of zinc as a way to treat or reduce symptoms of the cold virus. Still, the data from years of scientific studies are mixed.
The most recent published data reviewed the results of 15 previous studies. The research found that taking zinc, either as a syrup or lozenge, through the first few days of a cold may shorten the length of the illness. It also appeared to prevent colds in people who used it over the course of about five months.
In other studies, researchers found no differences in cold symptoms between those who took zinc and those who took a placebo or sugar pill.
What do these findings on zinc and colds mean to you and your family? For now, the study results on using zinc as a cold remedy are inconclusive. For every study showing a positive benefit with zinc, there’s another study showing no benefit at all. Many experts say that if there is any benefit in taking zinc or zinc lozenges, it is very minor.
There are a few important factors about the use of zinc for the common cold. One is that the formulation (gluconate, sulfate, acetate) and some flavoring additives may make a difference; this detail is still being worked out by researchers.
Is Zinc a Safe Cold Remedy?
The effectiveness of zinc as a cold remedy relies on frequent dosing during the illness. Short-term use of zinc -- less than five days -- has not lead to serious side effects, but can cause mouth irritation, a metallic taste, and stomach upset. Experts recommend that zinc should not be taken for more than five days. Long-term use of zinc -- for more than six weeks -- can lead to copper deficiency.
Zinc nasal sprays are known to cause a loss of the sense of smell in animals, and there have been several reports of people having decreased sense of smell or completely losing their sense of smell from zinc nasal sprays. Due to the risk of a loss of smell, the FDA issued a warning for consumers to stop using several nasal sprays containing zinc.
Zinc is necessary for optimal health and is safe to take when ingested through food sources such as seafood and eggs. But supplementing with higher doses of zinc, particularly long term, can be toxic.
What’s the Bottom Line on Zinc and Colds?
While some research has shown some benefit from zinc lozenges and nasal sprays, studies have been inconsistent. Additional research is needed to see if, in fact, zinc is an effective cold remedy. Zinc’s side effects, especially when nasal sprays or gels are used, may outweigh any potential benefit, and the benefit may be minimal, at best.