Doctor Explains Common Cold Myths: Wet Hair, Vitamin C, and Chicken Soup

"Brilliant marketing."

As America emerges from a deep winter chill, it may be tempting to blame cold symptoms on freezing temperatures. But when it comes to the common cold, myths about prevention far outnumber the facts. Between the “wet hair” idea, chicken soup, and everyone’s favorite go-to — vitamin C — it’s hard to tell what’s actually going to keep you healthy. Here, the co-director of a national poll on cold prevention that released its results Monday explains what actually works.

Dr. Gary Freed is a pediatrician at C.S. Mott Children’s Hospital in Michigan who co-directed the national survey, which asked parents about the strategies they use to prevent their kids from getting sick. Of all the parents that took part, 70 percent admitted they still use “folklore” strategies to prevent colds in their kids.

“They were just the standard things that people do,” Freed tells Inverse. “People thought that they could prevent the cold by not going out with wet hair, not going to sleep with wet hair, spending more time indoors, spending more time outdoors, things like that.” Here, he explains why strategies for both cold prevention and treatment — an important distinction — don’t actually work.

Wet Hair

One of the popular folklore strategies that parents mentioned in the poll was not letting kids go outside or go to sleep with wet hair. It kind of makes intuitive sense: Going outside or lying on a pillow with dripping hair makes your head cold, and that can’t be good, right?

“Well, here’s the deal,” says Freed. “These things have been passed down generation to generation and have been around for a really long time. They were conceived before we knew what actually caused diseases. Someone thought of that before we knew that there were viruses and we knew that viruses caused cold.”

Even somewhat scientific explanations — like “feeling cold weakens your immune system and makes you more susceptible to the cold virus” — simply have no evidence to back them up.

“Like anything, we would seek to find explanations for why certain things would happen,” Freed says, referring to people in the pre-virus era. “And people would find associations with certain things. It doesn’t mean that those were causal associations, they just were associations. So these were all things that were thought about before we knew that viruses caused colds. Not wet hair.”

Emergen-C
Emergen-C is strongly marketed as a cold prevention supplement.

Vitamin C and Supplements

Despite what’s said by orange juice manufacturers, immune-boosting supplements, and marketers of Emergen-C, the ubiquitous 1,000-mg packet of crystallized, fruity-flavored vitamin C, the nutrient doesn’t really do much to prevent or treat a cold. The survey showed that 51 percent of parents gave their child an over-the-counter vitamin or supplement to prevent colds despite there being no evidence that they work.

“It’s brilliant marketing,” says Freed about Emergen-C, which is not sold as “medicine” but has an urgent-sounding name suggesting a first line of defense.

Ditto for other forms of vitamin C. Experts at Harvard Medical School note that it has “modest prevention power,” but to be effective, you’d have to take it every day and “not just at the start of cold symptoms.”

“No, it’s all a myth,” says Freed. “The data show that it makes absolutely no difference in preventing colds. They’re marketed very heavily.”

Rice chicken vegetable soup in saucepan with spoon
Chicken soup, though comforting, won't do much to prevent a cold. It's not a bad way to treat one, though.

Chicken Soup

It is hard to deny that a steaming bowl of chicken soup during a cold helps being sick suck less. Even Freed will admit that the “comfort food” has some benefits for treating a cold, but it plays absolutely no role in preventing a cold.

“So, chicken soup does a couple of things,” he says. “It provides liquids, which is a great thing for anyone — we should not become dehydrated. And secondly it has nutritional value. But it’s not going to prevent a cold.”

In the same vein, all the vitamin C in Emergen-C may not do much to prevent a cold, but all the water you dissolve it in might help your body recover.

So What Actually Works?

For all the worthless strategies that parents use to prevent their kids from getting colds, the survey did turn up one positive statistic: 99 percent of parents encouraged strong personal hygiene, which is the only thing that’s been proven to work to prevent colds.

If there are cold virus particles around, washing hands, not putting hands near mouths and noses, and avoiding shared utensils and drinks are the only strategies that have been scientifically shown to work. The survey also showed that 84 percent of parents did “household cleaning,” which can also help if it involves sanitizing potentially virus-laden surfaces and objects that are handled often.

“Parents are trying these different things because they think they’re going to help their kid. But rather than spend their money on vitamins and supplements, they should buy their kid a book and really make a difference in their kids’ lives,” says Freed.

Asked what kind of book would help — a primer on viruses, perhaps — Freed responded: “Anything! Just have a book and stop wasting your money on supplements and vitamins.”