Ingredient spotlight: Echinacea

Echinacea is one of the most widely used, and widely misunderstood, herbs of the modern era. Every part of the plant has been the subject of scientific scrutiny, with ideas about which part to use, how long for, and in what types of patients differing vastly between experts.

Herbalists tend to side with the traditional uses of the plant, adopted by the Eclectic physicians of North America (late 19th/early 20th centuries) from Native American tribes. Let’s have a look at these traditional indications, as well as some of the scientific research that supports it. We’ll then touch on how best to use echinacea in light of these findings.

Traditional uses of echinacea

Native Americans preferred the root of echinacea and used mainly Echinacea angustifolia, though Echinacea purpurea root has a very similar chemical profile and the species are used almost interchangeably by modern herbalists.

It was prescribed by Eclectic physicians for snake bite, syphilis, typhus, septic wounds, diphtheria, tuberculosis and scarlet fever. This supports the modern consensus that echinacea works mainly on the innate immune response - the immediate response your body mounts when it is exposed to a viral or bacterial threat.

Due to its stimulatory effect on immunity modern writers have suggested that echinacea should not be used in conditions characterised by a hyperactive immune response, like allergy or autoimmunity. There is in fact no evidence to support this view (1), and the Eclectics were not averse to using it for the treatment of thyroid problems, diabetes, psoriasis and even cancer. In my clinic, I continue to use it with success for allergies, chronic skin conditions, and autoimmune thyroid disease. 

How does it work?

The immune system is a wonderfully complex orchestra of cells and chemical signalling, and it’s tricky to know exactly how any substance impacts immunity - especially one as complex as a plant extract.

However, we can deduce from the plethora of in vitro (cell cultures) and in vivo (animal) research that echinacea root stimulates phagocytosis (white blood cell activity), increases natural killer cells (NK) cells and monocytes (a type of white blood cell), and modulates immunity via the body’s ‘cannabinoid’ system, acting mainly on CB2 receptors in immune tissue such as the spleen (2, 3, 4). The active principles in the plant are thought to be the alkylamides, which are captured best in an ethanolic extract and are highly bioavailable.

Another common myth - that echinacea shouldn’t be taken long term - was dispelled by a Swiss team of researchers in 2004. They showed that echinacea prepares resting monocytes for a quicker immune response, by inducing messenger RNA for an important inflammatory chemical called TNFα. However, in overstimulated monocytes it first reduces and then extends their TNFα response (5). This supports herbalists’ clinical experience that echinacea acts as an immunomodulator in chronic inflammatory conditions, and is perfectly safe for long term use. 

How to use echinacea

Dosage and timing are the crucial factors when it comes to echinacea. For upper respiratory tract infections like the common cold, research indicates it is best taken as a preventative, at 1 - 4.5g dried root per day.

At this dosage, it has been shown to prevent winter colds in stressed out medical students, and reduce infection rates when taken before and during long haul travel (6, 7).

For treating already established infections, a much higher dose is needed - up to 10-15g per day - and this is how the Eclectics used it. Of course, it’s also important to seek proper medical attention in case of a serious infectious disease.

For autoimmunity and other chronic inflammatory conditions, echinacea at a preventative dose may help decrease the presence of microorganisms causing inappropriate immune responses via ‘molecular mimicry’ - an established factor in the development of immune-related disorders. In these cases, treatment must be supervised by a clinical herbalist who knows their stuff. 

References

1. Bone & Mills (2013) Principles and Practice of Phytotherapy. 2nd ed. Elsevier UK.
2. Woelkart & Bauer (2007) The Role of Alkamides as an Active Principle of Echinacea. Planta Med 73(7): 615-623.
3. Sun, Currier & Miller (1999) The American coneflower: a prophylactic role involving nonspecific immunity. J Altern  Complement Med. 1999 Oct;5(5):437-46.
4. Raudner et al. (2006) Alkylamides from Echinacea are a new class of cannabinomimetics. Cannabinoid type 2 receptor-dependent and -independent immunomodulatory effects. J Biol Chem 281(20):14192-206.
5. Gertsch et al. (2004) Echinacea alkylamides modulate TNF-alpha gene expression via cannabinoid receptor CB2 and multiple signal transduction pathways. FEBS Lett. 577(3):563-9.
6. McIntosh A, D’Huyretter K, Goldberg B et al (1999) Infections prevention by herbal formulas in a high stress population. AANP Convention, Coeur d’ Arlene.
7. Tiralongo et al (2012) Randomised, Double Blind, Placebo-Controlled Trial of Echinacea Supplementation in Air 8. Travellers. Evid Based Complement Alternat Med. 2012; 2012: 417267.
9. Hubbert et al. (2006) Efficacy and tolerability of a spray with Salvia officinalis in the treatment of acute pharyngitis - a randomised, double-blind, placebo-controlled study with adaptive design and interim analysis. Eur J Med Res 11(1):20-6.