Echinacea for Preventing and Treating the Common Cold

Abstract

Echinacea preparations are widely used for common cold. Many consumers and healthcare professionals are not aware that products available under the term Echinacea may differ in their composition, due to the use of different species, plant parts, extraction methods and addition of other components. In 2005, a Cochrane review has been published to provide objective evidence whether the various Echinacea preparations are more effective than no treatment, more effective than placebo or similarly effective to other treatments in the prevention and the treatment of the common cold. In contrast to other reviews, the specific criteria for pooling of data from different trials have been predefined to assure a meaningful meta-analysis. In the meantime two further meta-analyses have been published. In the present mini-review, these latest meta-analyses are evaluated and discussed.

Key words

Echinacea - Asteraceae - common cold - meta-analysis

References

• 1 Woodwell D A, Cherry D K. National ambulatory medical care survey: 2002 summary.  Adv Data. 2004;  346 1-44
• 2 Arroll B, Kenealy T. Antibiotics for the common cold and acute purulent rhinitis (Cochrane Review). The Cochrane Library, (1). Chichester; Wiley 2004
• 3 Blumenthal M. Herb sales down 6 percent in mainstream market.  Herbal Gram. 2005;  66 63
• 4 Bauer R. Chemistry, analysis and immunological investigations of Echinacea phytopharmaceuticals. In: Wagner H, editor Immunomodulatory agents from plants. Basel, Boston, Berlin; Birkhäuser Verlag 1999: 41-88
• 5 Shah S A, Sander S, White C M, Rinaldi M, Coleman C I. Evaluation of Echinacea for the prevention and treatment of the common cold: a meta-analysis.  Lancet Infect Dis. 2007;  7 473-80
• 6 Schoop R, Klein P, Suter A, Johnston S L. Echinacea in the prevention of induced rhinovirus colds: a meta-analysis.  Clin Ther. 2006;  28 174-83
• 7 Linde K, Barrett B, Wölkart K, Bauer R, Melchart D. Echinacea for preventing and treating the common cold. The Cochrane Database of Systematic Reviews; Issue 1: 2006
• 8 Melchart D, Linde K, Worku F, Bauer R, Wagner H. Immunmodulation with Echinacea - A systematic review of controlled clinical trials.  Phytomedicine. 1994;  1 245-54
• 9 Gwaltney JM J r, Hendley J O, Patrie J T. Symptom severity patterns in experimental common colds and their usefulness in timing onset of illness in natural colds.  Clin Infect Dis. 2003;  36 714-23
• 10 Gagnier J J, Boon H, Rochon P, Moher D, Barnes J, Bombardier C. CONSORT Group. Recommendations for reporting randomized controlled trials of herbal interventions: Explanation and elaboration.  J Clin Epidemiol. 2006;  59 1134-49
• 11 Barrett B, Locken K, Maberry R, Schwamman J, Brown R, Bobula J. et al . The Wisconsin Upper Respiratory Symptom Survey (WURSS): a new research instrument for assessing the common cold.  J Fam Pract. 2002;  51 265-73
• 12 Barrett B, Brown R, Voland R, Maberry R, Turner R. Relations among questionnaire and laboratory measures of rhinovirus infection.  Eur Respir J. 2006;  28 358-63
• 13 Jadad A R, Moore R A, Carrol D, Jenkinson C, Reynolds D JM, Gavaghan D J. et al . Assessing the quality of reports of randomized trials: is blinding necessary?.  Control Clin Trials. 1996;  17 1-12
• 14 Barrett B P, Brown R L, Locken K, Maberry R, Bobula J A, D’Alessio D. Treatment of the common cold with unrefined Echinacea. A randomized, double-blind, placebo-controlled trial.  Ann Intern Med. 2002;  137 939-46
• 15 Linde K. Do Echinacea products prevent and shorten the common cold?. Focus Complement Altern Ther, in press
• 16 Gillespie E L, Coleman C I. The effect of Echinacea on upper respiratory infection symptom severity and quality of life.  Conn Med. 2006;  70 93-7
• 17 Jackson G G, Dowling H F, Muldoon R L. Present concepts of the common cold.  Am J Public Health. 1962;  52 940-5