News & Perspectives

The Evidence on Echinacea

Late January, along with September and April, are peak months for catching colds. Many people reach for echinacea (pronounced ek-in-NAY-sha), a top-selling herb in this country. But some recent studies have cast doubt on its effectiveness, generating such headlines as "Popular Herb Does Little for Colds."

One of these studies, conducted at the Center for Complementary Medicine Research in Munich, Germany, and published in the Archives of Family Medicine (Nov./Dec. 1998), involved 302 healthy volunteers who took either a placebo or one of two types of echinacea (E. purpurea or E. angustifolia) for 12 weeks. The researchers found that those who took the herb had a 10% to 20% lower risk of catching a cold, but that the number of people studied was too small to draw conclusions. Far from dismissing the herb, they called for further studies.

In addition, the trial examined only echinacea's role in preventing colds, not its effects once a cold had set in. In fact, the investigators cited two earlier solid studies, also conducted in Germany, showing that those who took echinacea at the first sign of a cold (scratchy throat, achiness) were less likely to develop a full-fledged cold, and colds did not last as long.

What the doctors take
A survey of our experts turned up some common recommendations: Chicken soup, hot tea with honey and lemon, over-the-counter pain relievers such as ibuprofen for fever and aches, and echinacea.

"There is ample evidence that echinacea is effective in shortening the duration of colds" says Varro Tyler, Ph.D., professor emeritus at Purdue University and a renowned authority on botanicals. "There's much less evidence that using it on a continual basis will prevent colds. But taken at the first sign of a cold, it may shorten the illness by two to four days."

The trick is to find a brand that works for you. Because most of the scientific studies of echinacea have been conducted in Germany, some experts advise using products that have been tested for effectiveness in that country. Three brands that fit the bill are EchinaGuard (Nature's Way), Echinaforce (Bioforce), and Esberitox (an herbal blend from Enzymatic Therapy that contains two types of echinacea, plus the herbs wild indigo root and white cedar leaf). But there are many more good echinacea products here in the U.S., says Mark Blumenthal, executive director of the American Botanical Council and English-language editor of The Complete German Commission E Monographs, an authoritative source on herbal medicines from Germany. If one brand doesn't work, try another.

Additional advice:
Echinacea comes in many forms, including liquids, tinctures, and pills. Products may be standardized to contain 3.5% echinacosides, the active ingredients in some forms of the herb. Other products are standardized to other active ingredients. And still others are not standardized at all. It's not necessary to buy a standardized extract of the herb, or to buy a tincture, for example, over a pill. Each of the many forms of echinacea may be effective. Again, select a brand that works for you. Teas and soups are also available (chicken soup with echinacea is among the latest offerings), but they are less likely to supply a standard dose of potent herb.

Experts agree that echinacea is generally safe, although some caution against taking the herb for longer than eight weeks at a stretch (it may weaken the immune system if used year-round) or if you have AIDS or an autoimmune disorder such as rheumatoid arthritis or multiple sclerosis. It has none of the side effects of off-the-shelf cold remedies, such as sleepiness and nasal dryness.

Suggested dose:
For prevention of colds: 200 mg a day. At the first sign of cold symptoms, increase the dose to 200 mg 5 times a day. Continue taking the herb until symptoms subside.

Further reading:
Varro Tyler, Herbs of Choice (1994) and The Honest Herbal (1993), Haworth Press; Mark Blumenthal, editor, The Complete German Commission E Monographs (American Botanical Council, Austin, Texas, 1998.

Date Published: 01/29/2001
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