4 Cold and Flu Old Wives’ Tales That Are Myths

Myth 2: Load up on vitamin C and zinc to get better, faster.

Taking large doses of vitamin C won’t help prevent a cold, and there’s really “no solid evidence” that it will decrease the severity of cold and flu symptoms or even shorten the duration of the illness, Conway says.

Though some physically active adults might benefit from some extra vitamin C, a meta-analysis that studied over 11,000 people found that taking vitamin C supplements for the common cold “is not justified” for the general population because therapeutic trials haven’t replicated the link that some studies have found. Still, “it may be worthwhile for common cold patients to test on an individual basis whether therapeutic vitamin C is beneficial for them,” the authors stated.

Just be sure to check with your doctor before doing so. Most people get enough vitamin C from their diets, and dietary supplements, while sold over the counter, are not risk-free. Some can cause side effects and may interact with other medications. For example, vitamin C may reduce the effectiveness of some statins and blood thinners.

Zinc’s efficacy as a treatment for cold and flu symptoms also isn’t supported by scientific research. Studies that evaluated the efficacy of zinc lozenges and syrups found mixed results.

If you feel better after dissolving an over-the-counter zinc or vitamin C powder into a glass of water, thank that glass of water — it’s good hydration.

Myth 3: Chicken soup will cure a cold. 

The idea that chicken soup is good for the soul may not be grounded in science, but the placebo effect is. That is, in some limited cases, believing something will work can make it work. So if you feel a sense of warm nostalgia — good vibes — from sipping a bowl of soup, that may make you feel better, subjectively. Whether this soup actually helps you recover is a different matter.

One popular study published in the journal Chest conducted more than two decades ago by University of Nebraska Medical Center researcher Stephen Rennard, M.D., and his wife, Barbara Rennard, among others, put Barbara’s grandmother’s recipe — a brew full of fresh vegetables — to the test. The study found that certain types of chicken soup, including the homemade recipe, had a mild anti-inflammatory effect on the blood of healthy volunteers.

The researchers said the soup might help improve cold symptoms because something in it — they couldn’t figure out what, exactly — restrained the movement of neutrophils, a type of white blood cell that fights infection. The reduced movement of the neutrophils “may reduce activity in the upper respiratory tract that can cause symptoms associated with a cold,” explains a news release that accompanied the study. 

This effect was modest, the authors noted in a more recent article, also published in Chest, and the study was not a clinical trial, so “no conclusions could be drawn about clinical effect, either good or bad,” the authors said.

“The nutritional benefits from chicken soup in accelerating the recovery from a cold are probably minimal,” Immergluck says.

That said, soup can soothe a sore throat. And breathing in a soup’s steam — taking in a big breath, then letting that aroma linger — can, if only for a moment, help clear out the gunk that’s lodged in your nose and throat. Moisture is what helps here, so try a nice cup of tea. A steamy shower or bath can do the trick — or essentially anything that works like a humidifier.

And since soups are mostly liquid, they do help you stay hydrated. Getting enough liquids is especially important when you have a fever, because a fever leads to what the medical community calls “increased insensible losses.” Since you sweat more and “breathe out more fluid,” Conway says, “it’s easier to get dehydrated when you’re sick and when you have a fever.”

Myth 4: Feed a cold, starve a fever — or vice versa.

Whichever version you’ve heard, “starving” while you're sick — whether it’s a fever or a cold — isn’t something that most doctors would recommend. If you don’t eat enough, it’s more difficult to keep hydrated. 

“It’s never a good idea to have bad nutrition and to deprive yourself, especially when you’re sick. It’s really important to try to eat reasonably well, even if you don’t feel well,” Conway says. What’s even more important, he adds, is staying hydrated.

Editor’s note: This story, first published Dec. 8, 2022, has been updated.