by In the winter it can seem like everyone is sick. From passengers coughing and sneezing on the bus to children in daycare surrounded by multiple illnesses, the so-called common cold is a virus that is easily introduced into the body this time of year.
True to the nickname, it is estimated that a human will catch a cold more often in their lifetime than any other virus. While adults average three to four colds per year, children can get four or more each year. Between fatigue, runny nose, body aches, sore throat, and the occasional fever, it’s common for people to try to outsmart one of the 200 viruses that can cause the common cold.
A typical remedy is the mineral zinc, in the form of lozenges or supplements. We need zinc in our diet to grow and maintain our health. The mineral contributes to cell and DNA growth, heals damaged cells and can support a healthy immune system. But to do this, a person only needs small amounts of zinc.
For example, it is recommended that adult men have an intake of 11 milligrams per day; women, should have eight. Still, for more than 40 years, zinc has become a popular supplement as a preventative measure to strengthen a person’s immune system or even shorten the time a cold can last. Some people may even take zinc supplements to prevent colds altogether. But like the rest of the supplement world in the United States, zinc is highly unregulated. And is there scientific evidence to suggest it helps prevent and relieve colds?
“There is no concrete evidence to show that zinc is useful in treating the common cold,” Dr. Barbara Bawer, a family physician at The Ohio State University Wexner Medical Center, told Salon. “Unfortunately there are not enough studies or good studies available; Of those that are there, some show that it is useful, and others show that it is not.”
“There is no concrete evidence to show that zinc is useful in treating the common cold.”
A recent Cochrane review, published in May 2024, of 34 published studies in both adults and children found that taking zinc can help reduce the duration of cold symptoms by about two days. Cochrane reviews are incredibly rigorous and considered the highest standard in medical science. However, the systematic review of the publication found that the evidence for zinc was “inconclusive”.
“When zinc is used to treat colds, there may be a reduction in the average duration of the cold in days, although it is uncertain whether there is a reduction in the risk of a persistent cold at the end of follow-up ,” says the researcher. researchers wrote.
The review also states that potential benefits “must be weighed against side effects.” Common side effects of zinc reported in the studies reviewed included difficulty with bowel movements, nausea, and an unpleasant taste. There have even been reports of zinc-induced anosmia syndrome, which means a loss of smell, from zinc nasal sprays.
Since the 1980s, zinc products have been marketed as a treatment for the common cold. Then a published study comparing people with colds who took zinc lozenges with those who did not take zinc lozenges found that the mineral shortened the time people felt sick from their colds by as much as seven days. But since then, there have been dozens of other studies attempting to investigate the benefits of taking zinc for the common cold.
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“Even the studies that show improvement only show that there may be a decrease in the number of days you have symptoms, but don’t eliminate the severity of the symptoms,” Bawer said. “As GPs we do not routinely recommend zinc given the poor evidence available.”
William Schaffner, professor of infectious diseases at Vanderbilt University Medical Center, told Salon before the 1980s that zinc was seen as a “folk medicine.” He said there is some truth that it could potentially help shorten the duration of a cold, but it is a “modest effect.”
“And obviously you’re going to have to use zinc for a long period of time,” Schaffner said. “Most people aren’t keen on that because it can leave a metallic taste in your mouth.”
As for side effects, Bawer added that there are concerns that zinc may make some antibiotics or water pills “less effective” when taken together. “If taken in too high doses, it can also lead to a decrease in immune function, copper deficiency and a change in iron function,” Bawer added.
Then there’s the problem that people may not know what’s actually in their zinc supplements. Indeed, the U.S. Food and Drug Administration considers zinc supplements to be dietary supplements; there is no way to guarantee quality or let consumers know what else the supplements contain.
“Unfortunately, zinc is not highly regulated like most supplements,” Bawer said. “The FDA does not regulate the effectiveness or safety of supplements, or even the labeling of the supplement.”
When it comes to dietary supplements, the FDA only requires “reasonable assurance” that dietary supplements do not pose a “significant or unreasonable risk of disease or injury.” Several studies have shown that as many as 70% of supplement labels do not match what is in them.
Still, some people may turn to zinc for cold prevention. In that case, Bawer says the typical dosage is up to 40 mg per day, which can be divided into two or three doses throughout the day.
But more importantly, there are other ways to prevent colds, Schaffner pointed out.
“The most important thing you can do is try to avoid people who are coughing and sneezing, which is easy to say but difficult to do in respiratory virus season,” Schaffner said. Of course, wearing a mask can help, especially if you’re the one who is sick, to prevent others from becoming infected. Masks are not only useful for preventing COVID-19. “The other thing is ensuring good hand hygiene.”
In other words, preventing colds may have more to do with your behavior and less to do with what you put into your body, perhaps as simple as washing your hands.
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