Cochrane Review of Safety and Efficacy of Echinacea Preparations Shows Trend of Small Preventive Effect for Common Cold Symptoms

摘要

Preparations of the echinacea plant of the daisy family (Asteraceae) are used widely to treat or prevent the common cold. Three different species of the genus Echinacea — E. purpurea, E. pallida, and E. angustifolia — are used medicinally Echinaceapreparations vary greatly, utilizing different parts of the plant (fresh or dried root, aerial parts [leaf and/or flower], fresh-pressed juice from aerial parts, and combinations thereof), various manufacturing methods, and other herbs or homeopathic components are sometimes added. The authors of this paper conducted a systematic review to assess whether or not evidence from randomized controlled clinical trials exists to support the efficacy and safety of echinacea preparations compared with placebo inpreventing and/or treating the common cold. (Multiple authors have written about the challenge of conducting a meaningful meta-analysis of trials involving echinacea preparations, insofar as the clinical literature is based on so many different types of preparations.1,2)