Random test of echinacea shows little effect on cold symptoms

Monday, January 3, 2011; 11:13 PM

something to sneeze at
Random test of echinacea shows that it had little effect on cold symptoms

THE QUESTION When coming down with a cold, many people turn to the herb echinacea. But does it work in reducing the severity of cold symptoms or the length of time that they last?

THIS STUDY randomly assigned 719 people, 12 to 80 years old, who had just developed signs of a cold to take echinacea, a placebo or nothing. They recorded their symptoms twice a day and periodically had nasal washes to test for biological signs of a cold. Symptoms of a week-long cold lasted, on average, about a half-day less for those who had taken echinacea than for those who had not. Colds were about 10 percent less severe in the echinacea group. Statistically, the scientists said, there was virtually no difference between those who did and did not take the herb.

WHO MAY BE AFFECTED? People with a cold, an ailment that develops an estimated 1 billion times in a year among U.S. residents. No surefire cure has been found.

CAVEATS Information on symptoms came from the participants' assessments. The differences in results between people who did and did not take echinacea were small enough that they may have occurred by chance. People who took echinacea took the equivalent of about 10 grams of dried echinacea root the first day and about five grams a day for the next four days; different formulations may yield different results.

FIND THIS STUDY Dec. 21 issue of Annals of Internal Medicine (www.annals.org).

LEARN MORE ABOUT the common cold at www.familydoctor.org. Learn about echinacea at www.nccam.nih.gov/health.

- Linda Searing

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.

© 2011 The Washington Post Company