Of all the potential remedies, vitamin C is probably the best known–and it comes in tasty drops. But as for effectiveness, it gets an F. The C myth was started by the otherwise brilliant chemist Linus Pauling, who became convinced that large doses could stop a cold’s symptoms and shorten its duration. Early studies hinted that Pauling might be right, but scientists now say those results were evidence of little more than a placebo effect. (Patients who knew they were taking C fared well, but those who took it unknowingly did no better than the control group.) Everyone seems to agree that large doses of vitamin C cause only one thing: diarrhea.
The results on zinc are less clear. In some studies it cut colds short and reduced several symptoms by as much as half; in others it did nothing. “It’s been very difficult to reconcile,” says cold researcher Ron Turner of the University of Virginia. He thinks there may be a placebo effect at work here, too. But many doctors swear by zinc, so it may be a good bet. And though traditional zinc lozenges do taste–how shall we put this?–disgusting, Zicam has a new quick-dissolving chewable that’s much more palatable. For the truly squeamish, there’s a nasal powder.
As for herbs, you might as well just use most of them to season your chicken soup. Goldenseal, first used by the Cherokees, can interfere with anticoagulants, so it’s best to avoid it altogether if you’re on those medications. Astragalus and elderberry aren’t bad for you, but there’s little research indicating they’re good for you, either. The only herb favored by science is echinacea–and even that is controversial. A new study from The Journal of the American Medical Association shows that it keeps kids from getting colds, but others suggest it’s useless for adults. Echinacea comes in three forms that may vary in effectiveness. Because the herbal industry is almost completely unregulated, there’s no way to know which one you’re getting off the shelf.
All this means Big Pharma has a big hole to fill. Because colds are caused by many germs, they’re difficult to target with pharmaceuticals (heavy side effects are unacceptable when treating a relatively innocuous disease). But a few drugs are in the pipeline, including pleconaril, an antiviral that targets many different cold germs. The FDA originally shot down an oral version of pleconaril because it interfered with hormonal birth control. Drugmaker ViroPharma hopes a new nasal form will be safer; if it wins approval, it could be available by 2006. Until then, though, you’re probably best off relying on the only “cures” known to work for everyone: time and chicken soup.
