Echinacea – Uncertainty Remains On Its Ability To Reduce Occurrence Of Colds

Echinacea in a cup of tea on a wooden table.
Echinacea in a cup. Copyright: / 123RF Stock Photo

Overview

Echinacea is commonly sold as an over the counter herbal medicine for treating colds and flu. Given that in the USA, one billion episodes of cold are reported highlights just how much of a nuisance the attack by rhinoviruses which cause colds actually pose, mainly economically. In the USA, about 40% of lost work time and 30% of time lost from school are attributed to symptoms from colds (Kirkpatrick, 1996).

Echinacea species are native to North America. The plant now grows in the Western hemisphere and is noted for its horticultural beauty as well as health properties. Echinacea was the original traditional herbal remedy of the Great Plains Indian tribes. Later, settlers followed the Indians’ example and began using echinacea for medicinal purposes as well.

For a time, echinacea enjoyed official status as a result of being listed in the US National Formulary from 1916-1950. However, use of echinacea fell out of favour in the United States with the discovery of antibiotics. There is also a lack of scientific evidence supporting its use but if antibiotics continue to lose their functional performance to kill bacteria then renewed interest in the bioactives of echinacea will return. Perhaps the most interesting clinical feature is its role in supporting the immune system which may well be the basis for any activity shown against colds

Nine species are known all collectively by various common names:-

  •  Purple Coneflower,
  • American Coneflower,
  • Kansas snakeroot,
  • Black Sampson or Sampson root
  • Black-eyed Susan (normally reserved for the Thunbergia vines with bright yellow-orange flowers and black spot).

The species involved are

  • Echinacea purpurea
  • Echinacea angustifolia
  • Echinacea pallida

The clinical studies have been reviewed (Barrett, 2003).

Studies In Treating the Common Cold


The clinical studies examining the efficacy of Echinacea have produced mixed results and is thought to only give marginal improvements in cough cold treatment.

One large clinical study has indicated that it might reduce the duration of a cold downsize as it were the severity (Barrett et al., 2010), especially when administered at the first signs of infection (Linde et al., 2006; Shah et al., 2007; Woelkart et al., 2008). However, such studies are too few, appear inconsistent and cannot easily be compared because of their difference sin treatment protocols, conclusions drawn and differences in preparations.  Jawad et al., (2012) conducted a very comprehensive randomised double blind study which appears to suggest that actually the duration of the cold is reduced rather than the number of colds. There is a critical review of this article to be found on the NHS web-site which highlights a number of flaws in the research. 

There are some studies that show no benefit whatsoever. Two NCCAM-funded studies could not find any improvement in symptoms either using fresh pressed juice from E. purpurea for treating colds in children, or as an unrefined mixture of E. angustifolia root and E. purpurea root and herb in adults.

One of the issues is using standardised samples of the plant which makes consistency between conclusions from different research sources difficult to corroborate. Three different species tend to be used, E. augustifolia, E. purpurea and E. pallida. Their phytochemical profile and activity varies with each species and cultivar and probably location.

There is no positive EFSA ruling on the product.

Inflammation

Echinacea may have immune modulating benefits.

Echinacea angustifolia root extract (Polinacea®) was shown in a small-scale study with 10 healthy subjects to control cytokine expression. The cytokines studied were interluekins  IL-2, IL-8, IL-6 and TNF-α. The main site of action was at the gene level where the mRNA for IL-2 and IL8 was up regulated whilst the genes for pro-inflammatory cytokines IL-6 and TNF-α were down regulated. That study gives an interesting insight into a possible mechanism by which Echinacea might operate. The extract contained a large molecular weight polysaccharide which is belived to be at the heart of the active in this case. It is possible however the active is most likely to be Echinacoside.

Echinacea Does Not Help In Curing Cancer

There are some myths which are supported by a number of complementary and alternative medicine web-sites and books which claim that Echinacea could be used to treat cancer. There is no evidence to support the claim of alleviating cancer although there may be some cell studies with tumor cell lines to suggest the news might be more positive. It might however help alleviate some of the symptoms or side effects of cancer such as diarrhoea or a sore mouth due to chemotherapy treatments.

Echinacea As A Tea

Our gut bacteria always need a boost. It’s thought that Echinacea might help promote healthy guts through our gut bacteria. To prepare a herbal tea, roughly chop a few leaves, flowers and roots of Echinacea. Place in a teapot with 1 litre of boiling water, steep for 5 minutes, strain and serve with honey.

Products Containing Echinacea

Please note this article contains links to our affiliate marketing partners and please read our affiliate disclosure

Fertin from Denmark marketed a gum containing 30 mg vitamin C, 3.3 mg of zinc and 13.56 mg of Echinacea extract for preventing the common cold. The first two ingredients have EFSA claims for immunity but not the latter, however the presence of Echinacea improves the marketing appeal for the product.

Polinacea® is a triply standardised Echinacea augustifolia root extract.

The Side Effects Of taking Echinacea

Echinacea is generally safe to take and serious side effects seem rare. It is reckoned that Echinacea should not be taken for longer than 8 weeks because of the side effects listed below.

The more common side effects of echinacea include:

  • headaches
  • dizziness
  • feeling sick
  • stomach ache
  • constipation
  • skin reactions (redness, itchiness and swelling) – these are more common in children

The Boots web-site reports that:-

“Children under 12 years old should not be given herbal treatments containing Echinacea because of the risk of anaphylaxis, a serious allergic reaction. Products containing echinacea carry this advice on their packaging labels.

Other reported side-effects of Echinacea include rashes, nausea, heartburn, itching, constipation and headache.”

People are more likely to experience allergic reactions to echinacea if they are allergic to related plants in the daisy family, which includes ragweed, chrysanthemums, marigolds, and daisies. Also, people with asthma or atopy  which is a genetic tendency toward allergic reactions may be more likely to have an allergic reaction when taking Echinacea.

Revised 25th January 2015

References

Barnes, J.,  Anderson, L.A., Gibbons, S. and Phillipson, J.D. (2005) Echinacea species (Echinacea angustifolia (DC.) Hell.,  Echinacea pallida (Nutt.) Nutt., Echinacea purpurea (L.) Moench): a review of their chemistry, pharmacology and clinical properties. J. Pharm. Pharmacol. 57, (8) pp. 929–954

Barrett, B. (2003). Medicinal properties of Echinacea: A critical review. Phytomedicine, 10(1), pp. 66-86.
 
Barrett, B., Brown, R., Rakel, D., Mundt, M., Bone, K., Barlow, S., & Ewers, T. (2010). Echinacea for Treating the Common ColdA Randomized Trial. Annals of internal medicine, 153(12), pp. 769-777
Dapas, B., Dall’Acqua, S., Bulla, R., Agostinis, C., Perissutti, B., Invernizzi, S., … & Voinovich, D. (2014). Immunomodulation mediated by a herbal syrup containing a standardized Echinacea root extract: A pilot study in healthy human subjects on cytokine gene expression. Phytomedicine, 21(11), 1406-1410 https://doi.org/10.1016/j.phymed.2014.04.034
 
Jawad, M., Schoop, R., Suter, A., Klein, P., & Eccles, R. (2012). Safety and efficacy profile of Echinacea purpurea to prevent common cold episodes: a randomized, double-blind, placebo-controlled trial. Evidence-Based Complementary and Alternative Medicine, 2012.
 
Kirkpatrick, G.L. (1996) The common cold. Prim. Care 23 pp. 657-6
 
Linde, K.,  Barrett, B., Wölkart, K., Bauer, R. and Melchart, D. (2006) Echinacea for preventing and treating the common cold,” Cochrane Database of Systematic Reviews, no. 1, Article ID CD000530.
 
Shah, S.A.,  Sander, S.,  White, C.M.,  Rinaldi, M. and Coleman, C.I. (2007) Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis,. Lancet Infectious Diseases, 7, (7) pp. 473–480.
 
Woelkart, L., Linde, K. and Bauer, R. (2008) Echinacea for preventing and treating the common cold,” Planta Medica, 74, (6), pp. 633–637
 

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