Can Echinacea Really Conquer the Common Cold?

Echinacea, a plant native to the U.S., was once the most popular cold and flu remedy in the United States until the introduction of sulfa antibiotics. The irony is that antibiotics are not effective for colds because colds are caused by viruses, not bacteria. Echinacea remains the most commonly used herb for respiratory infections in Germany.

Echinacea is found in three varieties, E. angustifolia, E. purpurea and E. pallida. Chemically speaking, it contains polysaccharides, flavonoids, caffeic acid, essential oils, alkylamides and polyacetylenes, all of which are considered to be pharmacologically active. Echinacea has immune system-stimulating qualities that include strengthening the ability of white blood cells to destroy invading microorganisms. It also stimulates the lymphatic system to remove waste and reduces the ability of an enzyme called hyaluronidase to prevent cells binding together to prevent infection.

All those polysyllabic words sound impressive, but can echinacea help fight the common cold?

In the July 2007 issue of The Lancet Infectious Diseases, a medical journal, a review of past echinacea studies has given new credibility to its efficacy as a cold preventive and curative. The analysis of some 700 echinacea studies involving almost 3,000 participants concluded that echinacea did appear to reduce the risk of contracting a cold by almost 60% as well as shortening its duration, but to what extent was not clear. But Craig I. Coleman, M.D., author of the analysis, pointed out in a New York Times article that there are over 200 species of cold virus and echinacea might be effective for only a few of those species and not for others.

Other studies have indicated that echinacea is most valuable in relieving the symptoms of colds as well as helping people get over them faster, rather than preventing colds in the long run. But one study concluded that echinacea taken on a long-term basis may actually decrease immune system function, so it's better to take it for short periods. There also remain questions about which type of echinacea is most effective.

According to Elson Haas, M.D., a preventive medicine doctor, echinacea can clean your blood and lymph glands, which helps circulate antibodies and remove toxins. Dr. Haas recommends taking one to two capsules twice a day for two weeks for a cold.

Dr. C. Norman Shealy, M.D., a holistic physician and neurosurgeon, believes that echinacea is the best way to treat microbial infections because it is effective against both bacteria and viruses. It can also be used as a gargle for sore throats. He recommends 1 cup of the decoction (the root boiled in water and strained) or 1 teaspoon of the tincture-which can be bought at any health food store and some pharmacies-every two hours for ten days.

Herbalists recommend taking echinacea for up to a week for a cold, and then taking two or three days off to rest the immune system before re-starting the herb. A number of herb experts believe that the liquid form of echinacea is more effective than tablets or capsules, and that the juice of E. purpurea may be the best of the three choices.

The evidence suggests that echinacea may be a wise choice if you get a cold, and it is certainly a better idea than antibiotics. Check with your doctor if you suspect that you have a more serious condition than a cold or if you're not getting any better. Please keep in mind that the safety of echinacea in young kids, pregnant or nursing women, as well as people with serious liver or kidney disease and immune disorders has not been determined, although it appears to be quite safe with only occasional minor side effects.