RETHINK ZINC
A couple of decades ago, zinc—in the form of zinc lozenges—became extremely popular as a remedy for the common cold and even for flu. The lozenges were important because zinc needed to dissolve slowly to coat the mouth and throat, where a cold or flu virus thrives.
Many people still pop a daily dose of zinc as soon as cold or flu symptoms occur and some folks even take them regularly as a cold and flu preventative throughout the winter. I haven’t been one of these. However, I just read an online Harvard University article that’s making me a believer. Here are excerpts from that November 19, 2021 piece by Robert H. Shmerling, MD, titled Time to stock up on zinc?
As if stubbornly high rates of COVID-19 aren’t giving us enough to worry about, welcome to cold and flu season!
Yes, colds and influenza, two well-known upper respiratory infections, will soon be on the rise. Last year we saw remarkably low rates of flu. Many experts don’t think we’ll be so lucky this year.
A new analysis reviewing available research suggests that over-the-counter zinc supplements could be one way to make cold and flu season a bit easier. Of course, this isn’t the first study to look into the mineral as an antiviral remedy, including for COVID-19. But the results of past research have been mixed at best: some studies find modest benefit, others find no benefit, and the quality of the research has been low. Also, some people experience bothersome side effects from it, such as upset stomach, nausea, and in some cases, loss of the sense of smell.
What did the study say?
Published in November 2021 in BMJ Open, the study looks at zinc for preventing or treating colds and flulike illness. The researchers reviewed more than 1,300 previous studies and narrowed the analysis down to 28 well-designed trials, which included more than 5,000 study subjects. Here’s what they found:
For preventing colds and flu-like illness:
- Compared with placebo, zinc supplements or nasal spray zinc are associated with fewer upper respiratory infections. The estimated effect was modest: about one infection was prevented for every 20 people using zinc.
- A few studies suggest preventive effects were largest for reducing severe symptoms, such as fever and flulike illness.
For treating colds and flulike illness:
- Compared with placebo, those who took zinc had symptoms go away about two days sooner. The study estimated that of 100 people with upper respiratory infections, an extra 19 people would have completely recovered by day seven due to this treatment.
- Some measures of symptom severity were lower for those treated with zinc (versus placebo): on day three of the infection, those taking it had milder symptoms. Further, there was an 87% lower risk of severe symptoms among those taking the supplement.
What else to consider before stocking up on zinc
While these findings suggest promise in the ability of zinc to prevent or temper cold and flulike illness, here are other points to consider:
- Side effects. Side effects occurred more often in those taking zinc (versus placebo), including nausea and mouth or nose irritation. Fortunately, none were serious. But they might be bothersome enough for some people to stop using the mineral.
- Zinc supplements are generally inexpensive. A daily dose of lozenges for a month may cost less than $2/month (though I also found certain brands for sale online for as much as $75/month).
The bottom line
Colds and flulike illnesses afflict millions every winter. You might feel as though it’s inevitable you’ll be among them. But you may be able to spare yourself the misery by following some simple, safe, and common-sense measures. As evidence mounts in its favor, perhaps these measures should include zinc.
As for me [Dr. Shmerling] I remain steadfastly on the fence. But it wouldn’t take much — perhaps one more large, well-designed, randomized controlled trial — to push me onto the zinc bandwagon.