Echinacea Does Little to Prevent Colds
Tue May 11, 2004
By Alison McCook

NEW YORK (Reuters Health) - Stocking your medicine cabinet with Echinacea may be a waste of time, as a new study shows the herbal medicine does not help prevent colds.

After exposing 48 healthy adults to a virus that causes the common cold, U.S. investigators found that people who took Echinacea were no less likely to develop colds than people who took an inactive placebo pill.

Consequently, people may be better off leaving Echinacea off of their grocery list, study author Dr. Steven Sperber of Hackensack University Medical Center in New Jersey told Reuters Health. "Echinacea did not prevent infection with the cold virus," he said.

The research was funded by the German company Madaus Aktiengesellschaft, which sells the Echinacea product used in the current study.

In the U.S. alone, consumers spend more than $300 million each year on Echinacea products, for the purpose of preventing and treating colds.

However, recent research has also cast doubt on whether the herbal preparation can treat colds. An NIH study published last year found that children who took Echinacea as soon as they developed a cold showed no difference in the severity or duration of cold symptoms than children who took a placebo pill.

To test the benefits of Echinacea in preventing colds, Sperber and his team asked 48 adults to inhale a strain of rhinovirus, a group of viruses that causes approximately 40 percent of colds in adults.

As described in the journal Clinical Infectious Diseases, half the participants took Echinacea pills for 7 days before being exposed to the virus and for 7 days after, while the others took a placebo pill over the same time period.

More than 90 percent of participants became infected with the virus. Although slightly fewer people taking Echinacea developed colds, statistical calculations showed that the difference could have been due to chance.

Similarly, although people taking Echinacea appeared to have fewer symptoms than the placebo group, those differences were also too small to rule out the effect of chance, the authors report.

Sperber noted that although Echinacea may not help prevent or treat colds, none of the people who took it reported any side effects linked to the medication. However, he added that people who take herbal products should be aware that they can interact with prescription medications.

Sperber added that additional experiments that include larger numbers of participants are likely needed to establish whether Echinacea can at least help reduce cold symptoms.

Clinical Infectious Diseases, May 15, 2004.