The study, which is published in the July edition of The Lancet Infectious Diseases, was carried out by a team of researchers led by Dr. Craig Coleman from the University of Connecticut School of Pharmacy, Hartford Hospital, Connecticut.
Though Echinacea has been touted as one of the most popular and frequently used herbal remedies, it still faces contradiction. In 2005, a large randomized trial of the remedy found Echinacea had no effect on preventing experimentally induced rhinovirus colds.
However, Coleman and colleagues reviewed 14 trials that studied the effect of Echinacea on prevention and treatment of the common cold and came to a conclusion that the medicine decreased the odds by 58 percent (the statistically significant odds ratio was 0.42 with a 95 percent confidence interval ranging from 0.25 to 0.71).
The new study found that if Echinacea is used in combination with vitamin C, it reduces cold incidence by 86 percent. Also, the remedy reduced cold occurrence by 65 percent when it was used as a protective against catching it naturally.
"With over 200 viruses capable of causing the common cold, Echinacea could have modest effect against rhinovirus but marked effects against other viruses," the researchers said.
According to Lancet Infectious Diseases, Echinacea is a family of nine plant species indigenous to North America and is the most commonly used herbal product or "nutraceutical", a term used to describe food supplements used as medicines.
