Echinacea: Not a Cure or Treatment for the Common Cold

For decades, people interested in alternative medicine have been using the herb echinacea in hopes of preventing, curing or lessening the symptoms of the common cold. But a new study confirms what a growing body of evidence already indicated: Echinacea just doesn’t work for cold sufferers (except, of course, for possible placebo effects). We first advised readers not to take this supplement or any of the other leading dietary supplements in the 2005 edition of Worst Pills, Best Pills.

Research published in the July 28, 2005 New England Journal of Medicineindicates that the herb Echinacea angustifolia, or echinacea, is no more effective than a placebo in treating upper respiratory tract viral infection such as the common cold. The study was a randomized, controlled trial supported by a grant from the National Center for Complementary and Alternative Medicine (NCCAM), a part of the National Institutes of Health (NIH).

The study involved 437 young, healthy volunteers who consented to be exposed experimentally to rhinovirus, a virus which is known to cause upper respiratory tract infections.

The researchers carefully produced three different echinacea preparations. The volunteers were randomly assigned to receive either preventative treatment with echinacea beginning seven days before being exposed to the rhinovirus or treatment for rhinovirus infection beginning at the time that the virus was administered to the volunteers, either with one of the three echinacea preparations or with placebo.

The study concluded that:

The results of this study indicate that extracts of E. angustifolia root [echinacea], either alone or in combination, do not have clinically significant effects on infection with a rhinovirus or on the clinical illness that results from it.

The editorial that accompanied the publication of this trial made the following pointed observation about the use of herbal remedies:

Indigenous populations — who used echinacea in various forms, including teas, local applications, and inhaled smoke — had no concept of disease states or their causes, nor could they distinguish medicinal effects from the natural course of an illness. Herbal texts list the use of echinacea by at least 13 tribes of Native Americans for the treatment of such widely diverse conditions as sore mouth and gums, cough, dyspepsia, toothache, bowel complaints, hydrophobia [rabies], and snakebite.

Depending on the culture, echinacea had many different established uses, but curing or preventing the common cold does not appear to have been among them. Then how did it come about that echinacea is a cure for the cold in 21st century America? Apparently we do not know the exact answer to this question.

The editorial notes that in early 19th-century America echinacea emerged as an “oral anti-infective” and a local application for wound healing; it then fell from favor after the introduction of antibiotics. But in the 1960s, the dietary supplement boom began, and echinacea then became a treatment for the common cold. The editorial also questions why the U.S. government, through NCCAM, continues to fund more studies on supplements such as echinacea that have already been proven ineffective by previous studies.

American consumers wasted an estimated $153 million on echinacea dietary supplements in 2004, down from $213 million in 2001, before other studies began to question the therapeutic effectiveness of this plant.

What You Can Do

You should not use echinacea dietary supplements for any condition. If you are, you are paying for a placebo.