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Echinacea Reduces the Risk of Recurrent Respiratory Tract Infections and Complications: A Meta-Analysis of Randomized Controlled Trials

Abstract

Introduction

Respiratory tract infections are common, and these infections occur frequently in children, susceptible adults, and older persons. The risk for recurrences and complications relates not only to the presence of viruses but also to immune function. Therefore, modulation of the immune system and antiviral interventions such as echinacea might reduce the risk of recurrences and possibly the development of complications.

Methods

MEDLINE, EMBASE, CAplus, BIOSIS, CABA, AGRICOLA, TOXCENTER, SCISEARCH, NAHL, and NAPRALERT were searched for clinical trials that studied recurrent respiratory infections and complications on treatment with echinacea extracts in a generally healthy population. Two independent reviewers selected randomized, placebo-controlled studies of high methodological quality and a Jadad score of ≥4. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated according to a fixed effect model.

Results

Six clinical studies with a total of 2458 participants were included in the meta-analysis. Use of echinacea extracts was associated with reduced risk of recurrent respiratory infections (RR 0.649, 95% CI 0.545–0.774; P < 0.0001). Ethanolic extracts from echinacea appeared to provide superior effects over pressed juices, and increased dosing during acute episodes further enhanced these effects. Three independent studies found that in individuals with higher susceptibility, stress or a state of immunological weakness, echinacea halved the risk of recurrent respiratory infections (RR 0.501, 95% CI 0.380–0.661; P < 0.0001). Similar preventive effects were observed with virologically confirmed recurrent infections (RR 0.420, 95% CI 0.222–0.796; P = 0.005). Complications including pneumonia, otitis media/externa, and tonsillitis/pharyngitis were also less frequent with echinacea treatment (RR 0.503, 95% CI 0.384–0.658; P < 0.0001).

Conclusion

Evidence indicates that echinacea potently lowers the risk of recurrent respiratory infections and complications thereof. Immune modulatory, antiviral, and anti-inflammatory effects might contribute to the observed clinical benefits, which appear strongest in susceptible individuals.

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References

  1. 1.

    Johnston SL. Cromolyns: treatment for the common cold? Clin Exp Allergy. 1996;26:989–94.

    Article  CAS  PubMed  Google Scholar 

  2. 2.

    Levandowski RA, Ou DW, Jackson GG. Acute-phase decrease of T lymphocyte subsets in rhinovirus infection. J Infect Dis. 1986;153:743–8.

    Article  CAS  PubMed  Google Scholar 

  3. 3.

    Aherne W, Bird T, Court SDM, Gardner PS, McQuillin J. Pathological changes in virus infections of the lower respiratory tract in children. J Clin Pathol. 1970;23:7–18.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  4. 4.

    Elkhatieb A, Hipskind G, Woerner D, Hayden FG. Middle ear abnormalities during natural rhinovirus colds in adults. J Infect Dis. 1993;168:618–21.

    Article  CAS  PubMed  Google Scholar 

  5. 5.

    Chidekel AS, Rosen CL, Bazzy AR. Rhinovirus infection associated with serious lower respiratory illness in patients with bronchopulmonary dysplasia. Pediatr Infect Dis J. 1997;16:43–7.

    Article  CAS  PubMed  Google Scholar 

  6. 6.

    Collins PL, Graham BS. Viral and host factors in human respiratory syncytial virus pathogenesis. J Virol. 2008;82:2040–55.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  7. 7.

    Pene F, Merlat A, Vabret A, et al. Coronavirus 229E-related pneumonia in immunocompromised patients. Clin Infect Dis. 2003;37:929–32.

    Article  PubMed  Google Scholar 

  8. 8.

    Message SD, Johnston SL. Host defense function of the airway epithelium in health and disease: clinical background. J Leukoc Biol. 2004;75:5–17.

    Article  CAS  PubMed  Google Scholar 

  9. 9.

    Fox JP, Cooney MK, Hall CE. The Seattle virus watch. V. Epidemiologic observations of rhinovirus infections, 1965–1969, in families with young children. Am J Epidemiol. 1975;101:122–43.

    CAS  PubMed  Google Scholar 

  10. 10.

    Gertsch J, Schoop R, Kuenzle U, Suter A. Echinacea alkylamides modulate TNF-alpha gene expression via cannabinoid receptor CB2 and multiple signal transduction pathways. FEBS Lett. 2004;577(3):563–9.

    Article  CAS  PubMed  Google Scholar 

  11. 11.

    Ritchie MR, Gertsch J, Klein P, Schoop R. Effects of Echinaforce(R) treatment on ex vivo-stimulated blood cells. Phytomedicine. 2011;18:826–31.

    Article  CAS  PubMed  Google Scholar 

  12. 12.

    Pleschka S, Stein M, Schoop R, Hudson JB. Anti-viral properties and mode of action of standardized Echinacea purpurea extract against highly pathogenic avian influenza virus (H5N1, H7N7) and swine-origin H1N1 (S-OIV). Virol J. 2009;6:197.

    Article  PubMed Central  PubMed  Google Scholar 

  13. 13.

    Shah SA, Sander S, White CM, Rinaldi M, Coleman CI. Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis. Lancet Infect Dis. 2007;7:473–80.

    Article  PubMed  Google Scholar 

  14. 14.

    Schoop R, Klein P, Suter A, Johnston SL. Echinacea in the prevention of induced rhinovirus colds: a meta-analysis. Clin Ther. 2006;28:174–83.

    Article  PubMed  Google Scholar 

  15. 15.

    Karsch-Völk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev. 2014;2:CD000530.

    PubMed Central  PubMed  Google Scholar 

  16. 16.

    Taylor JA, Weber W, Standish L, et al. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. JAMA. 2003;290:2824–30.

    Article  CAS  PubMed  Google Scholar 

  17. 17.

    Grimm W, Muller HH. A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med. 1999;106:138–43.

    Article  CAS  PubMed  Google Scholar 

  18. 18.

    Schmidt U, Albrecht M, Schenk N. Pflanzliches Immunstimulans senkt Häufigkeit grippaler Infekte. Natur- und Ganzheitsmedizin. 1990;3:277–81.

    Google Scholar 

  19. 19.

    Melchart D, Walther E, Linde K, Brandmaier R, Lersch C. Echinacea root extracts for the prevention of upper respiratory tract infections: a double-blind, placebo-controlled randomized trial. Arch Fam Med. 1998;7:541–5.

    Article  CAS  PubMed  Google Scholar 

  20. 20.

    Cohen HA, Varsano I, Kahan E, Sarrell EM, Uziel Y. Effectiveness of an herbal preparation containing echinacea, propolis, and vitamin C in preventing respiratory tract infections in children: a randomized, double-blind, placebo-controlled, multicenter study. Arch Pediatr Adolesc Med. 2004;158:217–21.

    Article  PubMed  Google Scholar 

  21. 21.

    Jawad M, Schoop R, Suter A, Klein P, Eccles R. Safety and efficacy profile of Echinacea purpurea to prevent common cold episodes: a randomized, double-blind, placebo-controlled trial. Evid Based Complement Alternat Med. 2012;2012:841315.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  22. 22.

    Moher D, Cook DJ, Jadad AR, et al. Assessing the quality of reports of randomised trials: implications for the conduct of meta-analyses. Health Technol Assess. 1999;3:1–98.

    Google Scholar 

  23. 23.

    Jadad AR, Moore RA, Carroll D, et al. Assessing the quality of reports of randomized clinical trials: is blinding necessary? Control Clin Trials. 1996;17:1–12.

    Article  CAS  PubMed  Google Scholar 

  24. 24.

    Moher D, Liberati A, Tetzlaff J, Altman DG, PRISMA Group. Preferred reporting items for systematic reviews and meta-analysis: the PRISMA statement. PLoS Med. 2009;6:e1000097.

    Article  PubMed Central  PubMed  Google Scholar 

  25. 25.

    Whitehead A. Meta-analysis of controlled clinical trials. Chichester: Wiley Ltd.; 2002. p. 352.

    Book  Google Scholar 

  26. 26.

    Hedges LV, Olkin I. Statistical methods for meta-analysis. London: Academic Press; 1985. p. 369.

    Google Scholar 

  27. 27.

    Berg A, Northoff H, Konig D, et al. Influence of echinacin (ED31) treatment on the exercise-induced immune response in athletes. J Clin Res. 1998;1:367–80.

    Google Scholar 

  28. 28.

    Turner RB, Bauer R, Woelkart K, Hulsey TC, Gangemi JD. An evaluation of Echinacea angustifolia in experimental rhinovirus infections. N Engl J Med. 2005;353:341–8.

    Article  CAS  PubMed  Google Scholar 

  29. 29.

    Turner RB, Riker DK, Gangemi JD. Ineffectiveness of echinacea for prevention of experimental rhinovirus colds. Antimicrob Agents Chemother. 2000;44:1708–9.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  30. 30.

    Sperber SJ, Shah LP, Gilbert RD, Ritchey TW, Monto A. Echinacea purpurea for prevention of experimental rhinovirus colds. Clin Infect Dis. 2004;38:1367–71.

    Article  PubMed  Google Scholar 

  31. 31.

    Schoeneberger C. The influence of the immuno stimulating effects of pressed juice from Echinacea purpurea on the course and severity of cold infections. Forum Immunologie. 1992;8:18–22.

    Google Scholar 

  32. 32.

    Weber W, Taylor JA, Stoep AV, Weiss NS, Standish LJ, Calabrese C. Echinacea purpurea for prevention of upper respiratory tract infections in children. J Altern Complement Med. 2005;11:1021–6.

    Article  PubMed  Google Scholar 

  33. 33.

    Hoheisel O, Sandberg M, Bertram S, Bulitta M, Schafer M. Echinaguard treatment shortens the course of the common cold: a double-blind, placebo-controlled clinical trial. Eur J Clin Res. 1997;9:261–8.

    Google Scholar 

  34. 34.

    Heinen-Kammerer T, Holtmannspötter C, Schnabel S, Motzkat K, Kiencke P, Rychlik R. Nutzenbewertung der Therapie chronisch rezidivierender Atemwegsinfekte mit Echinacin. Gesundheitswesen. 2005;67:296–301.

    Article  CAS  PubMed  Google Scholar 

  35. 35.

    Bauer R. In: Bauer R, Wagner H, editors. Echinacea: Handbuch für Ärzte, Apotheker und andere Naturwissenschaftler. Stuttgart: Wissenschaftliche Verlagsgesellschaft; 1990. p. 9–21.

    Google Scholar 

  36. 36.

    Jackson GG, Dowling HF, Spiesman IG, Boand AV. Transmission of the common cold to volunteers under controlled conditions. I. The common cold as a clinical entity. AMA Arch Intern Med. 1958;101:267–78.

    Article  CAS  PubMed  Google Scholar 

  37. 37.

    Fendrick AM, Monto AS, Nightengale B, Sarnes M. The economic burden of non-influenza-related viral respiratory tract infection in the United States. Arch Intern Med. 2003;163:487–94.

    Article  PubMed  Google Scholar 

  38. 38.

    European Scientific Cooperative on Phytotherapy (ESCOP). Echinacea purpurea herba/radix. In: ESCOP Monographs, 2nd edition, Suppl. New York, NY, USA: Thieme, 2009. pp. 91–109.

  39. 39.

    Barrett B, Brown R, Rakel D, et al. Placebo effects and the common cold: a randomized controlled trial. Ann Fam Med. 2011;9:312–22.

    Article  PubMed Central  PubMed  Google Scholar 

Download references

Acknowledgments

No funding or sponsorship was received for this study or publication of this article. All named authors meet the International Committee of Medical Journal Editors (ICMJE) criteria for authorship for this manuscript, take responsibility for the integrity of the work as a whole, and have given final approval for the version to be published.

Conflict of interest

Andreas Schapowal and Peter Klein have no conflict of interest to declare. Sebastian Johnston received consulting fees from Bioforce, for review of this work; grants and personal fees from Centocor; grants and personal fees from Sanofi Pasteur; grants and personal fees from GSK; grants and personal fees from Chiesi; grants and personal fees from Boehringer Ingelheim; personal fees from Grünenthal; grants and personal fees from Novartis; grants, personal fees and shareholding from Synairgen, personal fees from Bioforce, outside the submitted work; In addition, Dr. Johnston has a patent Blair ED, Killington RA, Rowlands DJ, Clarke NJ, Johnston SL. Transgenic animal models of HRV with human ICAM-1 sequences. UK patent application No. 02 167 29.4, 18 July 2002 and International patent application No. PCT/EP2003/007939, 17 July 2003 licensed, a patent Wark PA, Johnston SL, Holgate ST, Davies DE. Anti-virus therapy for respiratory diseases. UK patent application No. GB 0405634.7, 12 March 2004 licensed, a patent Wark PA, Johnston SL, Holgate ST, Davies DE. Interferon-Beta for Anti-Virus Therapy for Respiratory Diseases. International Patent Application No. PCT/GB05/50031, 12 March 2004 licensed, a patent Wark PA, Johnston SL, Holgate ST, Davies DE. The use of Interferon Lambda for the treatment and prevention of virally induced exacerbation in asthma and chronic pulmonary obstructive disease. UK patent application No. 0518425.4, 9 September 2005 licensed, a patent Wark PA, Johnston SL, Holgate ST, Davies DE. Anti-Virus Therapy for Respiratory Diseases. US Patent Application—11/517,763, Patent No.7569216, National Phase of PCT/GB2005/050031, 04 August 2009 licensed, a patent Wark PA, Johnston SL, Holgate ST, Davies DE. Interferon-beta for Anti-Virus Therapy for Respiratory Diseases. European Patent Number 1734987, 5 May 2010 licensed, a patent Wark PA, Johnston SL, Holgate ST, Davies DE. Anti-Virus Therapy for Respiratory Diseases (IFNb therapy) Hong Kong Patent Number 1097181, 31 August 2010 licensed, a patent Wark PA, Johnston SL, Holgate ST, Davies DE. Anti-Virus Therapy for Respiratory Diseases (IFNb therapy). Japanese Patent Number 4807526, 26 August 2011 licensed, a patent Wark PA, Johnston SL, Holgate ST, Davies DE. Interferon-beta for Anti-Virus Therapy for Respiratory Diseases. New Hong Kong—Divisional Patent Application No. 11100187.0, 10 January 2011 licensed, and a patent Burdin N, Almond J, Lecouturieir, V, Girerd-Chambaz Y, Guy, B, Bartlett N, Walton R, McLean G, Glanville N, Johnston SL. Induction of cross-reactive cellular response against rhinovirus antigens European Patent Number 13305152, 4 April 2013 pending.

Compliance with ethics guidelines

The analysis in this article is based on previously conducted studies and does not involve any new studies of human or animal subjects performed by any of the authors.

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Correspondence to Andreas Schapowal.

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Schapowal, A., Klein, P. & Johnston, S.L. Echinacea Reduces the Risk of Recurrent Respiratory Tract Infections and Complications: A Meta-Analysis of Randomized Controlled Trials. Adv Ther 32, 187–200 (2015). https://doi.org/10.1007/s12325-015-0194-4

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Keywords

  • Complications
  • Echinacea
  • Meta-analysis
  • Recurrences
  • Respiratory tract infections