Lest you think I’m against alternative medicine (see previous post) I’m not. I am wholeheartedly for any effective, safe treatment. Evidence about alternative therapies can be hard to find, sadly. Nevertheless, I made a list of stuff I’ve been asked about for treating colds over the last two weeks. I thought I’d lay out the fact and fiction about these popular treatments.
First, some standard, boring doctor disclaimers:
- Alternative products are food to the Food and Drug Administration and aren’t tested like drugs.
- As food, there is no standardized product. Is a burger from White Castle the same as McDonald’s? Wendy’s? No. When you test Echinacea, are all products the same? Purpurea or Pallida? In what dose? Is Nature Made’s product the same as Kroger’s? Nobody knows.
- Over 200 viruses cause the common cold. What works against rhinovirus might not against adenoviruses. This makes testing (pharmacologic or otherwise) very tricky.
Vitamin C:
Prevention: Not helpful, even in high doses.
Cure: Mixed. In high doses some studies (not all) suggest that the length of the cold might be shortened by a day or so.
Zinc:
Prevention: Not helpful.
Cure: Don’t use the nasal spray. It might destroy your sense of smell forever. If you can stand the metallic, astringent taste of zinc lozenges, you’ll need to start using them within 24-48 hours of your symptoms and use one every 2-3 hours to possibly decrease a little the severity and duration of your already short, self-limited illness.
Echinacea:
Prevention: CONSISTENTLY proven to be useless.
Cure: Perhaps a 10-30% decrease in severity of symptoms. However, there are plenty of studies which show no benefit whatsoever. Furthermore, Echinacea is related to ragweed. If you suffer from hay fever in the fall you should avoid Echinacea altogether.
Garlic:
Prevention: One very small study demonstrated one less cold a season.
Cure: No evidence.
Ginseng, American and Asian
Prevention: Mixed. There are a couple of trials demonstrating a decrease in the number of respiratory infections in a season, but not enough good evidence yet to recommend it. Ginseng interacts with a lot of commonly used drugs for diabetes, pain, mental health and blood clots, making safety potentially an issue.
Cure: No evidence.
Probiotics:
Prevention: In little kids, there are small studies demonstrating a moderate decrease in the number of respiratory infections. No good data on adults.
Cure: No data.
Things that DON’T work:
Airborne, Vitamin E, Oscillococcinum, goldenseal, bee propolis, boneset, wild indigo, peppermint, chamomile, meadowsweet, or linden flowers.
Lest you cry in your deadly nightshade, there is some hopeful news on the horizon. Andrographis, “Indian Echinacea” shows some promise in prevention and treatment. There’s not enough data yet on safety to recommend it. Given how much I hate being snotty, though, I will follow this closely. Maybe I’ll find a clinical trial and can offer my nose up to science. In the meantime I’m going to wash my hands, a proven way of preventing infection.
Victoria Rentel, MD (Ohio State University Student Health Services)
Prescribers Letter Vol 9 #29: Natural Medicines and the Clinical Management of Colds and Flu