Curing the Common Cold

We can eradicate smallpox, decipher the genome, and put a man on the Moon, but we can’t cure the common cold.

Well, maybe I can. I have a cartoon plaque, painted many years ago by my brother in a fit of creative zaniness, entitled “Milestones in Medicine: Dr. Harriet Hall Cures the Common Cold.”  It shows me masked and gowned for surgery, brandishing a chain saw. The legend explains my method, amputation of the head: “I guarantee you’ll never sneeze again.” (It goes on to say I am working on another deadly killer, spinal bijesus of the blowhole.)

From Chicken Soup to Vitamin C

Head removal might be effective, but it has certain drawbacks. Folk wisdom suggests other less drastic but also less effective remedies. “Feed a cold, starve a fever” (but what if you have both?).   Grandma’s chicken soup (which apparently really does help a bit).  My favorite: hang your hat on the bedpost and drink whiskey until you see two hats.

A doctor’s advice in 1919[1] for cold prevention was to live right: exercise, deep breathing, water, proper diet (never more than four kinds of food at one meal?!), and a balanced state of mind. Treatment consisted of cathartics, enemas, hot baths, bed rest, and a diet of absolutely nothing, except perhaps some lemon juice, until the symptoms subsided.

Linus Pauling, Nobel prize winning chemist, thought vitamin C could cure the common cold and he went on to invent orthomolecular medicine.  I will be kind and just say his work in medicine did not match the caliber of his work in chemistry.  After decades of conflicting studies, the consensus of science is that vitamin C may shorten the duration of colds by as much as a day, does nothing to prevent colds, is toxic in large doses, and mostly helps people whose diet is vitamin C deficient.

The Natural Medicines Comprehensive Database lists the following as “possibly effective” for colds:

Andrographis, Echinacea, Panax ginseng, great plantain, peppermint oil, white horehound, vitamin C, and zinc. No remedy merits a “probably effective” rating, much less an “effective” rating.

Echinacea showed promise until the recent NIH study shot it down. I have a friend who still believes in it. She says for the last 6 years, every time she has felt like a cold was coming on, she’s taken Echinacea, and she hasn’t had a single cold. I told her for the last 6 years, every time I have felt like a cold was coming on, I have NOT taken Echinacea, and I haven’t had a single cold either. So if she can claim taking Echinacea works to prevent colds, I can claim that NOT taking Echinacea works to prevent colds. Not taking it is cheaper.

Zinc may help a little, but not without risk. The manufacturer of Zicam has paid out millions of dollars to over 300 people who said it made them lose their sense of smell.

Homeopathy uses occilococcinum: start with duck liver, dilute the duck out of it, and hope the water remembers the duck. In my opinion, all that leaves is a quack.

If you want to go the Eastern route, you can treat colds with Chinese self-massage programs, mixtures of Chinese herbs, and acupuncture at the large intestine 4 point. Traditional Chinese medicine is more popular in California than in China: that should tell you something.

Airborne, Cold MD and Cold-FX – Much Ado About Little Science

There’s a wide choice of snake-oily products. Recycle an old idea, mix a little of this with a little of that, change a remedy slightly, and make new claims. Cold MD is a prime example: they mixed vitamin C and zinc with a “proprietary” mixture of herbs including Astragalus, Ginseng, and Echinacea, and they claim it “supports immune function,” increases your resistance by 312 percent, and helps you recover 94 percent faster. This claim is based on a clinical study of the main ingredient only, shedding doubt on the rationale for including the other ingredients! It is “not intended to prevent or treat any disease,” shedding doubt on the rationale for taking it. There is always a new product of this sort, and when you try to trace the claims, the evidence just fizzles out.

A product called Airborne is popular: developed by a school teacher, it’s an irrational mixture of ingredients supported by enthusiastic testimonials but by no scientific trials. After Michael Shermer debunked Airborne in his “Skeptic” column in Scientific American, he was contacted by a representative of the company that makes Cold-FX. They essentially said, “Maybe Airborne’s cold remedy doesn’t really work, but ours really does.” Does it?

Gee, it must work – it was advertised on the tray tables on the airplane the last time I flew. Cold-FX was developed in Canada and popularized by a hockey commentator. It’s a patented mixture of complex sugars derived from American ginseng.  Why American ginseng? Only Chinese ginseng, a different species, had been previously thought to possibly have an effect on colds.

If I wanted to develop a cold remedy, neither species of ginseng would be my first choice. If I wanted to make money, I might well pick ginseng as a relatively innocuous plant with warm fuzzy associations with folk remedies. I might pick out one of its many ingredients and make a meaningless but patentable change, get my own company to run a couple of preliminary trials and publish them, misrepresent the trials as proving more than they do, and market the product aggressively. Since colds are so unpredictable and often ill-defined, a cold remedy is ideal to confuse people.

The Canadian government was confused into letting them advertise it as a cold remedy, but our FDA was far warier. Shipments were seized at the border. The FDA made them remove the false statements. This results in the surreal situation that people are buying it as a cold remedy but nowhere in its advertising or labeling does it say it is for colds. In fact, a disingenuous disclaimer explains that the word “cold” only refers to the cooling properties of the plant! The package says “diet supplement – strengthens the immune system.” It also clearly states “not intended to prevent or treat any disease.”  If you wanted a DVD player, would you buy something that wasn’t called a DVD player but only an “entertainment device… not intended to play DVDs”? I wouldn’t, but apparently there are a lot of people who would, people whose hope exceeds their ability to read labels.

The company’s motto is “Trust the Science.” What does the science show? Two independent experts, professors of pharmaceutical sciences at the University of BC, took a close look at the company’s 3 most recent trials. They were underwhelmed.[2]

Two different studies involved nursing home patients with an average age of 82 (not your typical consumer).  The ginseng groups reported just as many respiratory illnesses and symptoms as the control groups.  They had to count positive lab cultures for two specific viruses and combine the two studies to find any significant difference: 1% vs 9%. They interpreted this as “reducing the risk of colds by 89%.” That’s terribly misleading. Who cares if Cold-FX reduces culture rates by 8% if it doesn’t make a whit of difference in how sick people feel?

In the third, larger study, the ginseng group caught 0.68 colds each and the placebo group, 0.93 colds. If you believe this study, Cold-FX apparently can prevent one-quarter of a cold per person – not terribly impressive. This study was published in the Canadian Medical Association Journal,[3] accompanied by a critical article urging caution. In addition to the problems pointed out there, I noticed something else very strange. Untreated cold symptoms can last 2-14 days and typically resolve in a week. In this study, the placebo group averaged 16.5 days of symptoms (for less than one cold). There is something drastically wrong here. This unexplained anomaly sheds doubt on the study’s conclusions.  You could just as well conclude that the ginseng didn’t shorten colds, but the placebo prolonged them!

These amount to preliminary studies, not the kind of studies that can guide clinical recommendations; and even in the most favorable interpretation, the effect was small.  When a real breakthrough in cold prevention or treatment comes along, you won’t learn about it in product advertisements; it will be all over the media as one of the biggest news stories of the year. While we’re waiting….

What Are We to Do?

Wear your galoshes? Avoid getting chilled? Won’t help. We catch more colds in the winter not because it is colder, but because we spend more time indoors with other people. The virus is spread through airborne droplets and also “handed off” by touching things like doorknobs and pens. The virus can be picked up by another person hours later and transferred to the nose or even to the conjunctiva when you unthinkingly rub your eyes. Howard Hughes tried a simple, effective approach – isolation from germ-carrying humans. That works, but if you don’t want to be a hermit or the boy in the bubble, there are simple, practical ways to limit your exposure to the cold virus: avoid sick people, and don’t touch your mouth, nose or eyes without first washing your hands.

You’ll eventually catch a cold anyway. When you do, you can either treat or save your money. Without treatment, a cold lasts about a week; with treatment it will be gone in about seven days. Try this: reconceptualize your situation as good luck rather than bad – a chance for a mini-vacation.  Stay home, veg out, pamper yourself, and catch up on your sleep.

That may be “cold comfort” but it won’t waste your “cold” hard cash.

[1] R. L. Alsaker, M.D., Curing Catarrh Coughs and Colds. New York: Frank E. Morrison, 1919.

[2] Baines, D. “Trust the science? Take a look at it first” Vancouver Sun, Feb. 25, 2006. Available online at

[3] Predy, GN, et al. Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trial. Canadian Medical Association Journal, 173(9):1043-8, Oct.2005.

This was originally published as a SkepDoc column in Skeptic magazine.

Dr. Hall is a contributing editor to both Skeptic magazine and the Skeptical Inquirer. She is a weekly contributor to the Science-Based Medicine Blog and is one of its editors. She has also contributed to Quackwatch and to a number of other respected journals and publications. She is the author of Women Aren’t Supposed to Fly: The Memoirs of a Female Flight Surgeon and co-author of the textbook, Consumer Health: A Guide to Intelligent Decisions.

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