Among the respiratory conditions for which essential oils show promise is bronchial asthma.
Asthma affects some 339 million people worldwide and is the most common chronic disease among children (Morales, 2018). Asthma is characterized by chronic inflammation of the airways of the lungs with symptoms that include wheezing, shortness of breath, tightness of the chest, excessive mucus production, and cough. Asthma may also be classified as atopic (extrinsic) or non-atopic (intrinsic), based on whether symptoms are precipitated by allergens (atopic) or not (non-atopic) (Kumar at al, 2010). Allergic mechanisms are involved in about half of people with asthma.
Atopic asthma commonly involves an infiltration of the airways by components of the immune system such as eosinophils, mast cells, and lymphocytes together with a thickening of the bronchial walls and hypertrophy/ hyperplasia of the smooth muscle of the airways (Cheng et al, 2018). (Hypertrophy refers to an increase in the size of cells; hyperplasia is an increase in the number of cells.)
A number of essential oils and their components have demonstrated through in vitro and in vivo research studies the capacity to modulate immune responses in a way that helps to relieve the symptoms of asthma. (The term in vitro refers to a research study or experiment which is carried out in a laboratory using a test tube or lab dish; the term in vivo refers to a medical test or procedure that is done on a living organism, whether animal or human.) Various essential oil components have shown effectiveness in the management of bronchial asthma through preventing eosinophil migration and reducing oxidative damage to the lung (Beck-Speier et al, 2005).
In vitro studies investigating the treatment of asthma with essential oil of ginger (Zingiber officinale) and the essential oil components limonene (from yuzu) and thymol (found in thyme) have demonstrated the ability to enhance immune responses by regulating pro-inflammatory cytokines (Gandhi et al, 2019). Cytokines are produced by many different cells, including immune cells such as macrophages, T lymphocytes, and mast cells. Cytokines play a role in responses to infection, immune challenges, and inflammation, and promote airway hyper-responsiveness and the expression of inflammatory genes in bronchial asthma.
The inhalation of essential oil of lavender (Lavandula angustifolia) has been shown to extinguish eosinophils in bronchoalveolar fluid and lung tissue as well as reduce levels of Interleukin-5 (Ueno-Iio et al, 2014). Eosinophils have a central key role in the pathogenesis of asthma, while IL-5 Interleukin-5 is a driver of eosinophil production, and influences the severity of eosinophilic inflammation.
The essential oil compound 1,8-cineole is commonly found in essential oils employed in the relief of respiratory conditions, such as Eucalyptus radiata. Research studies have shown 1,8-cineole to be a cytokine immunomodulator which, together with its antioxidant activities, gives it potential protective effects against the progression of inflammatory airway diseases. This suggests that, in addition to its mucolytic activity, 1,8-cineole addresses excessive mucus production, making cineole-rich essential oils of value in the aromatherapeutic treatment of sinusitis as well as asthma (Juergens et al, 2020).
Cineole-rich essential oils of eucalyptus (Figure 1) in particular possess a combination of antimicrobial, immunomodulatory, anti-inflammatory, antioxidant, analgesic and antispasmodic effects beneficial in cases of bronchial asthma (Sadlon & Lamson, 2010).
Figure 1. Eucalyptus globulus
In terms of administration, various sources recommend the diffusion and direct inhalation of essential oils in cases of bronchial asthma. However, there is a risk of bronchospasm in response to the inhalation of sufficient concentrations of essential oils among those who experience hyper-reactivity of the airways. Children, in particular, are vulnerable.
A safer starting point for helping to improve the condition of those with asthma is to administer essential oils topically, via a chest rub applied to the front and back of the thorax. For adults free of skin disorders, I would recommend a blend of the following essential oils diluted in a base oil at a concentration of approximately 5%.
30% Eucalyptus (Eucalyptus radiata) (9 drops)
30% Lavender (Lavandula angustifolia) (6 drops)
20% Sweet orange (Citrus × sinensis) (6 drops)
10% Ginger (Zingiber officinale) (3 drops)
10% Thyme (Thymus vulgaris ct thymol) (3 drops)
Apply 1-2 times per day for a period of up to 3 months.
Let us know about your experience once you try the blend.
To your aromatic success!
Guest Post By:
Gabriel Mojay LicAc, CertEd, FIFPA
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Cheng Z, Wang X, Dai LL, Jia LQ, Jing XG, Liu Y, Wang H, Li PF, An L, Liu, M (2018). Thymic stromal lymphopoietin signaling pathway inhibition attenuates airway inflammation and remodeling in rats with asthma. Cell Physiol Biochem, 47, 1482-96.
Gandhi GR, Vasconcelos ABS, Haran GH, Calisto VKDS, Jothi G, Quintans JSS, Cuevas LE, Narain N, Júnior LJQ, Cipolotti R, Gurgel RQ (2019). Essential oils and its bioactive compounds modulating cytokines: A systematic review on anti-asthmatic and immunomodulatory properties. Phytomedicine. 2019 Jan 31:152854.
Juergens LJ, Worth H, Juergens UR (2020). New perspectives for mucolytic, anti-inflammatory and adjunctive therapy with 1,8-cineole in COPD and asthma: Review on the new therapeutic approach. Adv Ther. 2020 Mar 21. doi: 10.1007/s12325-020-01279-0.
Kumar V, Abbas A, Fausto N, Aster J (eds) (2010). Robbins and Cotran pathologic basis of disease (8th ed). Saunders.
Morales E. (2018). The Global Asthma Report 2018.
Sadlon AE, Lamson DW. Immune-modifying and antimicrobial effects of Eucalyptus oil and simple inhalation devices (2010). Altern Med Rev. 2010 Apr;15(1):33-47.
Ueno-Iio T, Shibakura M, Yokota K, Aoe M, Hyoda T, Shinohata R, Kanehiro A, Tanimoto M, Kataoka M (2014). Lavender essential oil inhalation suppresses allergic airway inflammation and mucous cell hyperplasia in a murine model of asthma. Life Sci. 108, 109-115.