Is zinc really effective in catching a cold?difficult to say

A clear cough, a sore throat, and a stuffy head all make you feel like a cold is coming. Or maybe you're already showing cold symptoms. If you stop by a drug store, you'll find over-the-counter products on the shelves containing the mineral zinc that claim to shorten the duration of symptoms.

The promise of salvation is tempting. But do these products work?

A new analysis of published research on zinc and cold viruses concludes that there is not enough evidence to show whether over-the-counter zinc treatments are effective in preventing colds.

For people who take lozenges or inhale nasal sprays when they have a cold, available research shows that these products can help relieve symptoms, said Darryl Noto, an assistant professor at the Maryland College of Integrative Medicine. It has been shown that it may be possible to shorten the duration by up to two days. first author of the paper, Published Wednesday by the nonprofit Cochrane.

However, these studies have been highly inconsistent in terms of zinc dosage, type, patient population, and definition of cold symptoms, leaving “little to very low confidence in the evidence,” the review said. ing. “Additional research will likely be required before firm conclusions can be drawn.”

In other words, it's been almost 30 years since zinc lozenges were administered. The first to appear on the market was We cannot yet say for sure whether these will be as effective as they say.

“We are not saying [zinc] “There's some benefit to colds,” Nolt said. “We're not saying it's not. We're saying we need more consistent evidence that is reproducible. That's the basis of good science.”

The era of zinc cold products began in 1996, when researchers at the Cleveland Clinic Foundation convinced 100 of the clinic's employees to volunteer their time. Research theme Within 24 hours after developing a cold.

Half were given a placebo, and half were given lozenges containing 13.3 milligrams of zinc gluconate every two hours they were awake for as long as their symptoms persisted. The group receiving zinc felt better after an average of 4.4 days, while the placebo group felt sick for an average of 7.6 days.

Most people get enough of the important nutrient zinc through their regular diet. This mineral is abundant in red meat and poultry, and is also found in many grains and fruits. (Oysters include the following) add more zinc It provides more per serving than any other known food, with one serving containing nearly 300% of the daily recommended intake. )

scientist I don't know exactly How minerals work to reduce cold symptoms. But the idea of ​​an over-the-counter method to alleviate the suffering of a cold turned out to be very popular.

Total U.S. sales of zinc products such as Zicam and Cold-Eeze were $340 million in 2023, said Hannah Esper, editor-in-chief of the Nutrition Business Journal. Demand for zinc and other supplements exploded during this era. COVID-19 pandemicIn 2020, zinc sales increased by 168.3%.

Based in the UK, cochrane According to the company's website, the company uses rigorous research methods to evaluate existing scientific evidence and produce reports that help people make decisions about their health.

For this review, the Cochrane team looked at 34 studies conducted in 13 countries that investigated zinc products and the treatment or prevention of colds.

Author Susan Wieland, assistant professor and director of the Cochrane Division of Complementary Medicine at the University of Maryland School of Medicine, said it's difficult to draw strong conclusions from the available research because studies tend to measure different things. Stated.

Colds are “a very common condition, but difficult to study,” Wieland said. They come and go quickly, making it difficult to enroll research subjects. The doses and types of zinc administered to study subjects varied widely.

“Each study design is different. So there are different doses, different dosage forms, different patient populations, different exclusion and inclusion criteria, and different outcomes. [and] “The definition of a cold,” said Dr. Jason Yee, an antimicrobial stewardship pharmacist at Cedars-Sinai Medical Center in Los Angeles. He was not involved in this review. “It's very difficult to draw the same conclusion based on different studies.”

Doctors said they were not surprised by the results.

“I agree with that study. … It is consistent with my clinical experience at the hospital.” Dr.Samia Faiz, an internal medicine specialist at the University of California, Riverside Health. “In general, healthy people may be able to take zinc supplements if they feel better or feel comfortable. If you have any discomfort or stomach upset, you may want to take these supplements. You shouldn’t.”

Over-the-counter zinc products are generally harmless to patients battling colds, he said. Dr.pritish toshThe Mayo Clinic infectious disease doctor and researcher said popping lozenges “should not come at the expense of what's really important, like getting enough rest, staying hydrated, and taking care of yourself.” .

So why do we keep throwing cash at these things when we only have a hunch that they will work?

When a cold hits, “it's natural for consumers to reach for things that might help alleviate their symptoms. But the average consumer is unsure of the evidence and effectiveness of these products. “We don't have enough knowledge of the literature and research to show that it's limited,” Yi said.

Buying a lozenge or huffing a nasal spray can make you feel more in control when you're at the mercy of time and your immune system, Nott said.

“Having a sense of control makes a lot of people feel good and feel like they're doing something,” Nolt says. “Even if it's not.”

Times researcher Scott Wilson contributed to this report.