Echinacea is typically known to be one of the most widely used herbal supplements for the common cold. However, in a recent study that was published in the New England Journal of Medicine and sponsored by National Institutes of Health (NIH), a group of scientists from the University of Virginia questioned the ability of echinacea to reduce symptoms of the common cold and help patients recover quicker.
In this randomized, double-blind, placebo controlled trial, 399 volunteers were split into two groups. The first group, which was further divided into subgroups, received three different doses of the echinacea extract; the second group received placebo. Five days later, both groups were exposed to a rhinovirus through a nasal spray.
The investigators found no difference in infection rates between the echinacea and placebo groups. Approximately 90% of the subjects in both groups became infected. Symptoms such as sneezing, runny noses, and sore throats were also about the same, with more than half in both groups showing classic signs of a clinical cold.
Although the study was well designed, trade groups have argued that the doses used were too low to be effective. The standard dose is approximately three times higher than the dose used in this study. The dose issue needs to be resolved before the efficacy of echinacea in treating the common cold can be ruled out.