Here's some good news for those of you who get hit with the common cold from time to time: Zinc may help to reduce your risk of getting a cold - and its duration and severity if you do get one.
A recent report in the Cochrane Database of Systematic Reviews summarized the available data on the role of zinc in preventing and treating colds in otherwise healthy people, and came up with some encouraging conclusions.
The authors of the study looked at 13 trials where zinc was used to treat colds and two trials where zinc was used to prevent colds. They found that people who started zinc supplements within 24 hours of the onset of cold symptoms, and took the zinc for at least five consecutive days, had a significant reduction in the severity and duration of symptoms.
They also found that those people who took zinc on a daily basis (e.g., in a multivitamin/mineral tablet) were at lower risk of developing colds. In fact, when adults and children were given zinc for at least five months, they had fewer colds and fewer days missed from school. They also needed antibiotics less frequently.
In the treatment studies, zinc was given either as a lozenge or a nasal gel, where it was able to act directly in the throat to kill the cold virus. However, loss of smell has been reported in people using nasal zinc, so the FDA recommends avoiding it. Zinc lozenges are felt to be safe, however, and come in many forms; zinc acetate and zinc gluconate preparations are the ones that seem to work the best for colds.
Look for a type of lozenge that provides 13 to 25 mg of elemental zinc per lozenge; the dose is one lozenge, dissolved slowly in the mouth, every two hours during the day until symptoms have resolved. The lozenges can cause some mild nausea or bad taste in the mouth, but they are otherwise safe as long as they are discontinued after one to two weeks.
Why would zinc help to stop or prevent a cold? Zinc is important for a well-functioning immune system, so if you are deficient in zinc, you are at higher risk of infection. Zinc deficiency also contributes to impaired wound healing, hair loss, and loss of taste and smell. Zinc deficiency is common worldwide, especially among infants, teenagers, women and the elderly, often because of poor diet.
In addition, certain commonly used medications can interfere with the absorption of zinc, including ACE inhibitors and thiazide diuretics (both used to treat high blood pressure and heart disease) as well as medications that reduce stomach acid, such as like Prilosec and Pepcid.
The best food sources of zinc include oysters and other shellfish, organ meats, beef, pork and chicken; these provide 1 to 8 mg of elemental zinc per serving. Since many people don't eat these foods regularly, it's probably best to take a daily multivitamin/mineral tablet with about 15 mg of zinc; the tablet should also contain 1 to 3 mg of copper.
Are there risks to taking zinc? The answer is yes: Zinc taken in high doses can actually impair immune function. Too much zinc also leads to copper deficiency, and an imbalance of copper and zinc can cause anemia and other health problems. Zinc can also inhibit the absorption of certain antibiotics such as the tetracyclines or quinolones (e.g., Ciprofloxacin) in addition to other meds, so be sure to talk with your doctor if you are taking these meds before you start taking zinc.
For the average healthy adult, however, a daily multivitamin/mineral preparation with 10 to 15 mg of zinc should help to keep you healthy, and zinc lozenges taken at the first signs of a cold should help you to recover more quickly - and that's always welcome news!
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Drs. Kay Judge and Maxine Barish-Wreden are medical directors of the Sutter Downtown Integrative Medicine program. Have a question related to alternative medicine? E-mail fitness@sacbee.com.
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(c) 2011, The Sacramento Bee (Sacramento, Calif.). Distributed by Mclatchy-Tribune News Service.