Josephine P. Briggs, M.D.
Echinacea—What Have We Learned and Where Are We Going?
Everyone gets colds. Doctors’ offices are packed with patients seeking relief from symptoms or looking to treat occasional more serious complications. There are also countless home remedies, and store shelves are filled with over the counter medicines and herbal supplements. Among the latter is echinacea—a popular herbal supplement made from the stems, leaves, or roots of the purple coneflower.
As we head into the cold and flu season, it’s not surprising that the press has given a lot of attention to the NCCAM-funded study by Barrett et al. in the Annals of Internal Medicine. Although the authors noted that there were small trends in the direction of a benefit from echinacea—an average half-day reduction in duration, or an approximate 10 percent decrease in severity—they concluded that this dose and formulation of echinacea does not significantly change the course of the common cold.
These results and conclusions are consistent with a large body of previous clinical research. That studies of herbals are often not definitively positive or negative is a challenge that we are attempting to address as a major theme of our upcoming strategic plan (to be released in early 2011): the need for basic and translational research on natural products. In particular, the plan calls for better understanding of biological effects and the development of biomarkers or other translational tools prior to the initiation of lengthy, complex, and expensive clinical trials. With such knowledge and tools it will be possible to design clinical studies that test mechanistic hypotheses at the same time that we study clinical outcomes. For example, inclusion of biomarkers derived from basic and translational research would greatly increase insight, particularly into “negative” or equivocal studies.
For now, the best advice for treating the common cold is to stay home, get plenty of rest, and drink lots of fluids.