TUESDAY, Dec. 2, 2003 (HealthDayNews) -- The common cold appears wily enough to withstand yet another assault.
Researchers have found that, in children, the natural remedy echinacea made no dent in the duration or severity of upper respiratory infections (URIs), one of mankind's most stubborn enemies.
"We couldn't show any efficacy at all," says a disappointed Dr. James A. Taylor, lead author of the study and a professor of pediatrics at Seattle Children's Hospital and Regional Medical Center. "I have done studies on conventional medicines. They were negative. I'd like to find something that actually worked."
Echinacea also seemed to increase the number of rashes, says the study, which appears in the Dec. 3 issue of the Journal of the American Medical Association.
Others feel that it's too soon to make a judgment, however. "This is not the final answer," says Dr. Mary Jo DiMilia, an assistant clinical professor of medicine and pediatrics at Mount Sinai School of Medicine in New York City. DiMilia points out the wide array of preparations available make it difficult to draw firm conclusions about the product.
According to the study authors, the average child has six to eight colds every year, each lasting seven to nine days. None of the usual drug suspects (antihistamines, cough suppressants, decongestants, etc.) appear to work in children under the age of 12.
Echinacea, which is supposed to strengthen the immune system, is one of the biggest selling herbal remedies in the United States, with reported annual sales exceeding $300 million.
And while studies have looked at the efficacy of echinacea, none have been definitive, mostly due to methodological flaws.
This study looked at echinacea purpurea, one of three major types of echinacea used for medical purposes. "It had been tested before, and was as controlled conditions as we could get from the manufacturer, and it was similar to products that had shown some evidence of efficacy in other studies," Taylor explains. "Also, because we were studying children, we wanted a product that could be taken as a liquid and didn't have any alcohol."
With colleagues at Bastyr University in Kenmore, Wash., which specializes in natural health sciences, Taylor recruited 524 children aged 2 to 11, then randomly assigned them to receive either echinacea or a placebo. All the participants were healthy when the trial started and received the echinacea or placebo at the first sign of symptoms.
Ultimately, data was collected on 707 URIs that occurred in 407 children, including 337 who were treated with echinacea and 370 with the placebo.
There was no difference between the groups in duration of the infection or severity of the symptoms. However, a rash did occur in 7.1 percent of the URIs treated with echinacea versus only 2.7 percent of those treated with a placebo.
There was, however, one unexpected outcome that was not part of the study's original mandate. There were fewer second or third colds in the echinacea treatment group, indicating the herb may still have a role to play in prevention.
"It was a statistically significant decrease, so it's possible that the echinacea didn't help the cold for which it was given but did something to the immune system that made you less likely to get another cold," Taylor says. It's also possible that this was a "statistical fluke." Taylor is hoping to follow this up with additional studies.
Also, the fact that many different preparations and strengths of echinacea are available means that other formulas may be effective, though Taylor admits to being more pessimistic than before.
The American Botanical Council, a nonprofit group that promotes the use of echinacea, said the researchers downplayed the finding on subsequent colds. That is "an important benefit," the group says in a statement.
DiMilia recommends that her patients use a mixture of the purpurea root and the pallida root (900 milligrams three times a day for two weeks) at the first sign of symptoms or "if you happen to walk into a room and you feel like there are a lot of people with colds."
"Even in adults, if you start after they're sick, most of the time, it doesn't make much of a difference," she adds. "If you can do it at the onset of exposure, that's when you see a big difference. I have done this even in my own house. If someone is sick, I will make everyone take echinacea."
More information
For more on upper respiratory infections, visit Lucile Packard Children's Hospital. The American Botanical Council has more on echinacea.
