Echinacea may not only help to reduce the symptoms of a cold but may also help to prevent infection with some cold viruses, said U.S. researchers on Monday.
People who regularly took echinacea had a 58 percent lower risk of catching the common cold, according to the researchers, who did not study the herb’s effects directly but instead looked at the results of 14 other studies using a system called ‘meta-analysis’.
The study was led by Dr. Craig Coleman of the University of Connecticut School of Pharmacy, he cautioned that the studies involved only 1,600 people. They also involved various echinacea products, so it was still difficult to know 100% whether and how echinacea might work to prevent colds and their symptoms.
“All the studies trended toward reducing a patient’s odds of developing a cold. But none of them was large enough — they didn’t have enough patients — to prove it statistically,” said Mr Coleman in a telephone interview.
Coleman’s study, which was published in the journal Lancet Infectious Diseases, is one of the few to take a look at the effects of echinacea. It is a widely used product that is derived from several species of flower.
“Someone needs to do a really large, well-done, randomized trial. However that is unlikely to occur in the immediate future because there is a lack of funding,” Coleman said.
Drug companies would not be able to patent such a widely used herbal product, he also noted.
The Findings However Differ From A 2005 Study
In 2005, the New England Journal of Medicine published a study that found that echinacea was of no benefit in stopping colds or their symptoms. Coleman said it looked at only part of the picture.
“That study took healthy volunteers and then inoculated them, then put a little Q-tip (cotton swab) up their nose. The problem is there are more than 200 kinds of viruses that cause colds,” Coleman said.
Also the team that did this particular study only looked at a rhinovirus.
“Maybe it doesn’t work against that kind of virus, but it does against the other 199 kinds.”
Mr Coleman said it also appeared as if echinacea reduced the duration of a cold by 1.4 days on average, with symptoms dissappearing quicker that average.
One of the studies looked at how echinacea used together with with vitamin C reduced the number of colds by 86 percent.
The term echinacea refers to different parts taken from nine related plant species all indigenous to North America. It was originally used by Native Americans and is now the most commonly used “nutraceutical” product — a catchall term that refers to herbs and some supplemented foodstuffs.
Mr Coleman, a pharmacist by trade, said it does appear to stimulate the immune system, although no one quite knows how it does this.
Caution Is Advised
It might also cause harmful effects, and these need to be further looked into, he said.
“While echinacea is generally regarded as a safe substance, it hasn’t yet undergone any long-term safety evaluations,” Coleman said.
“So as with all supplements you should use it with caution.”
Patients whu suffer with autoimmune diseases such as lupus and multiple sclerosis should be particularly careful, he said. In addition, echinacea affects a liver enzyme that breaks down some pharmaceutical drugs, so using it with prescription medications could cause drug interactions that coud have serious consequences.