You take echinacea, eat garlic and drink herbal teas—but are you preventing a cold any more than your soda-drinking, candy-munching officemate? Do any of the cold remedies people swear by really work? What is fact and what’s folklore?
Miracle cures? Echinacea, zinc, garlic and other supplements
When a recent study published in The New England Journal of Medicine reported that echinacea didn’t prevent or help cold symptoms, you could almost hear the collective cry of despair from millions of herbal devotees. Some researchers are careful to point out that this study only showed that one specific formulation and dose of echinacea did not help with rhinovirus-induced colds in one group of subjects, but this “on the one hand, on the other hand” response is symptomatic of research findings on most cold remedies.
If you try to get to the bottom of whether any remedies work, you get qualified answers: “It depends on what you mean by ‘work,’ ” says Dr. Bruce Barrett, assistant professor of family medicine at the University of Wisconsin, Madison, who studies upper respiratory infections. “When compared against placebo in a blinded fashion, nothing has consistently reported more than a 20 percent benefit, meaning a reduction in the overall length and severity of a cold.”
Reducing the severity of a cold or the duration is probably enough of a promise for most people stocking up on lozenges and tissues, but researchers are divided on whether the studies that show even these limited benefits are sound. For every study that shows zinc, vitamin C or echinacea reduces the length or severity of colds, there’s one that shows no effect.
Many doctors will tell you flat out that these remedies don’t work, and it’s not worth the risk of taking unregulated supplements for any length of time. (Supplements are not subject to FDA review and approval.) Dr. John Swartzberg, professor of medicine at the University of California, Berkeley, and an editor of The Berkeley Wellness Letter is firm: “There are no supplements or herbs that have demonstrated activity to prevent or treat the common cold. The two that have been studied the most are echinacea and vitamin C, with clear evidence that they do not help.” Furthermore, taking too much of a supplement can cause problems. Too much zinc can actually have a negative effect on the immune system; too much vitamin C can cause diarrhea.
As for Airborne or Zicam, remedies that are very much in vogue at the moment, no reliable studies prove Airborne’s benefits, and the few Zicam studies were sponsored by the manufacturer and important details about the methodology were not disclosed. Swartzberg warns, “There's pretty good evidence that the inhaled form [of zinc] may damage the olfactory nerve (smell) and should definitely be avoided. Airborne is nonsense and there is much too much vitamin A in it to be considered safe.”
And as far as garlic goes, Swartzberg is similarly dismissive. “Garlic doesn’t work for anything except in cooking.” Although Barrett says that one trial suggested that the herb could prevent two-thirds of colds, researchers by and large remain dubious. “Maybe people just didn’t get close enough to the garlic eaters to give them a virus,” jokes Barrett.
Cold remedies: Is it all in your head?
Before you start cursing researchers and tossing your herbal tinctures and teas, consider one finding that bears consideration: the placebo effect. Barrett notes that, “In studies that look at whether, say, echinacea or zinc prevent or reduce cold symptoms, the results tend to show that having an actual treatment is just slightly better than being given a placebo. But being given a placebo is a fair amount better than no treatment at all.” In other words: Having a treatment is better than not having one—even if it’s just a placebo. Which could mean that the very act of thinking you’re taking something that will help your cold, helps your cold. “If you happen to think chamomile cures your colds, then it probably does. Not because chamomile cures colds. But probably through some mind-body relief mechanism that we don’t yet understand,” says Barrett.
