Essential Oils to Aid Post Viral Recovery of Anosmia
Relegated to background awareness while we amble through our daily life, viruses, for most of us, were mysterious, sometimes pesky, inhabitants of a distant domain – that is, until COVID-19 hit the worlds mainstream media headlines. Invisible to the eye, even smaller than bacteria, these infinitesimal particles, well, at least the notion of them, took the world by storm as they burst onto the stage.
Viruses, though, are not ‘new kids on the block’, nor, in deed, are they really, in spite of being invisible, backstage players. Present since the dawn of creation, long before humans arrived on the scene, these invisible particles tirelessly play a vital and indispensible role in our evolution and our on-going ability to adapt, survive and thrive in natures ever-changing environment.
Even with the strongest electron microscope, these micro and nano particles are difficult to accurately decipher; microbiology, in truth, has only just left the surface in its Star Ship Enterprise to dive into this universe ‘where no man has gone before’. According to the ships log, so far, it is known that viruses are extremely diverse and novel and, together with unicellular microorganisms, such as bacteria, fungi, archaea and protists, form one of the major components of earth’s intricate environmental web. They exist throughout the global eco-system, and are even found in extremely bleak locations that otherwise appear devoid of life; for example, in salty and soda lakes, the Sahara Desert, freezing polar environments, hot acid springs, in the dark cold depths of oceans, even in nuclear radiation sites. (Le Romancer 2007, Russ 2007)
Viruses are not ‘alive’ in the usual sense, because they do not fulfill all the criterion of a living entity (movement, nutrition, excretion, respiration, reproduction, growth and sensitivity); they ‘host jump’ and borrow energy from cells. For example, they apparently replicate rather than reproduce or divide, and in order to carry out this function they must first enter and tap into the resources of a suitable living host cell; thus, they appear to be parasitic.
The Qualities of Essential Oils
Essential Oils are multi dynamic adaptogens; that is, they support the immune system and the body’s resilience to stress. They stimulate the limbic system (the emotional brain), are antimicrobial, skin healing, hedonistic, and more. They work simultaneously on each body system; so, simply, for example, an essential oil selected to add to a dry skin remedy, may also ease mild depression and/or uplift mood and emotion, while also sharing it’s antimicrobial qualities to avert infection.
All essential oils possess anti-pathogenic and anti-microbial properties to varying degrees (one of the significant roles essential oils play within plants). They help protect the plant from pathogenic proliferation, among other roles. Many essential oils inhibit and slow the growth of bacteria, yeasts and moulds; certain essential oil molecules (especially, for example, those found in eucalyptus, lemongrass, rosemary and tea tree} affect the lipid structure of bacterial cell membranes in a way that increases its permeability, causing the cell to lose ions and other cellular components, which leads to the cells death. Some essential oils act synergistically, potentiating other anti-viral or medicinal agents, including biomedical antibiotics. (de Silver et al 2020, Nazarro et al 2013).
How are Essential Oils Detected?
Scent molecules (terpenes and terpenoids) are detected (like a key in a lock) by olfactory receptors located at the top of each nasal cavity that in turn relay nerve impulses to the Limbic System located in the brain. Odour receptors are also located in other parts of the body, for example, in the skin and other organs. However, by grand design, it seems, proximity of the master olfactory portal ensures immediate awareness and an instinctive reflexive response. Initially, protectively, we instantly decipher whether something is safe or noxious (do we accept or reject it?). The sense of smell, however, is a complicated process, involving a number of neurological and psycho-emotional mechanisms.
Essential Oils to Support Post-Viral Olfactory Rehabilitation
Post viral anosmia (loss of the sense of smell) is not completely understood, particularly because smell is a complex multi-dynamic process involving various nervous and brain system mechanisms, evoking, as described previously, both physiological and, often reflexive and instinctive, psycho-emotional responses, among other things.
Colds, influenza and COVID-19 are all corona viruses. However, unlike common cold and ‘flu viruses, which have been around for thousands of years, COVID-19 is a new (novel), highly transmissible virus, first identified in 2019 in Wuhan, the capitol of Hubei Provence in China. Symptoms of COVID-19 range from mild to severe, depending on the age and health condition of the host. In most cases people are not even aware they are infected; a high percentage experience no symptoms or mild ‘flu-like symptoms and recover without ill effect. Some people, however, experience severe or acute COVID-19, symptoms (a chronic cough, shortness, chest tightness, shortness of breath, cognitive dysfunction and extreme fatigue) and may continue to experience these symptoms for up to twelve weeks, in some cases even longer (Post COVID-19 Syndrome). (Venkatisan 2021) In this case, where lungs and breathing capacity have been compromised, direct olfactory inhalation of essential oils is not advisable, due to the risk of irritation.
In terms of disrupting the sense of smell, COVID-19 virus particles attach to and penetrate supporting ACE2 coated cells that surround and provide structure and nutrients to the epithelium at the top of the nasal cavity, hijacking and destroying these cells, causing dysfunction of the epithelium and the hair-like olfactory nerves projecting through the epithelium from the olfactory bulb. Sometimes the sense of smell diminishes without any other obvious symptom of infection. Up to 50% of people affected by COVID-19 report loss of their sense of smell. The sense of smell usually returns quite soon after recovery from infection, but for some it takes much longer; sometimes the sense of smell only partially returns or is never regained. Some pathogens, including viruses, may enter the higher brain region via the epithelium and olfactory nerve portals (Rebholz et al 2020)
Professor Thomas Hummel and colleagues (Damm et al 2013, Hummel 2009) devised a system of re-training olfactory receptors after the loss of the sense of smell, using four essential oils (rose, eucalyptus, clove and lemon) to stimulate re-growth and reactivation of olfactory receptors and epithelium supporting cells at the roof of the nose. In a BBC interview (29th November 2018) Professor Hummel (ear, nose and throat expert at the University of Dresden, Germany) confirmed that after deliberately sniffing each essential oil for twenty seconds in the morning and evening, using Sniffin Sticks (pen-like tubes containing the oil, held just at the entrance of each nostril) as a delivery mechanism, 45% of those tested recovered their sense of smell, whereas only 22% of people recovered without smell training. Some people experienced change in their perception of odours, attributed to the fact that not all receptors were recovered; this sometimes resulted in alteration in the nuances of some smells, sometimes appearing to improve the acuity of smells, and in other instances non-recovery of some receptors changed the smell, sometimes rendering normally unpleasant smells as pleasing, and vice versa.
The qualities of the four essential oils selected to stimulate the sense of smell extend beyond simple scent detection activation. Each scent is distinctive, and yet complex, revealing many layers and characteristics (see below), and also express qualities associated with taste. In Ayurveda and elemental modalities, for example, the taste (and qualities) of clove bud is aligned with bitter, eucalyptus leaves with pungent, lemon with sour and bitter, and rose petals with sweet. Bitter improves taste. Pungent (a taste between sour and bitter) is associated with the lungs and immune system, and so on. To be clear, I am not recommending the internal ingestion of essential oils here.
Collectively, these essential oils stimulate the immune system, may ease feelings of depression, grief, and anxiety and instil a sense of warmth, feeling grounded, clear-headed, and more. For example, clove bud essential oil is antiviral, stimulates memory and eases depression; eucalyptus globulus is antiviral, and is mentally and emotionally bracing and clearing; lemon is anti-microbial, averts cold and ‘flu, and eases stress related conditions; rose alleviates coughs, and eases grief, bereavement and a sense of loss, and so on.
To learn more about what a virus is and how essential oils may aid post viral recovery, among other elements, please refer to the full article in the Spring 2021 Aromatherapy Times Magazine.
- Russ, B., Dyall-Smith, M. (2007) Virus-host interaction in salt lakes. Current Opinion in Microbiology 10(4):418-424. https://www.researchgate.net/publication/6124993_Virus-host_interactions_in_salt_lakes
- Le Romancer, M., Gaillard, M., Geslin, C., Prieur, D. (2007) Viruses in Extreme Environments. Environmental Science and Bio Technology. https://link.springer.com/article/10.1007/s11157-006-0011-2
- de Silva, J. K. R. (2020) Essential Oils as Antiviral Agents, Potential of Essential Oils to Treat SARS-CoV-2 Infection: An In-Silico Investigation. International Journal of Molecular Science 21(10): 3426. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7279430/
- Nazaro, F., Fratianni, F., Martino, L. D., Coppola, F., De Feo, V., (2013) Effects of Essential Oils of Pathogenic Bacteria. Pharmacueticals (Basel) 6(12): 1451-1474. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3873673/
- Venkatesan, P. (2021) Nice Guideline on Long COVD. The Lancet, Respiratory Medicine, vol. 9 issue 2. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(21)00031-X/fulltext
- Rebholz, H., Braun, R. J., Ladage, D., Knol, W., Kleber, C., Hassell, A. W. (2020 Loss of Olfactory Function – Early Indicator for COVID-19, Other Viral Infections and Neurodegenerative Disorders. Frontiers in Neurology. Dementia and Neurodegenerative Diseases.
- Damm, M., Pickart, L. K., Reimann, H., Burkert, S., Goktas, O., Haxel, B., Frey, S., Charalampakis, I., Beule, A., Renner, B., Hummel, T., Huttenbrink, K-B. (2014) Olfactory Training is helpful in post-infectious olfactory loss: a randomized controlled multicenter study. Laryngoscope 124(4):826-31. https://pubmed.ncbi.nlm.nih.gov/23929687/
- Hummel, T. (2018) A simple flu, and simple infection: how effective is smell training at curing infection? BCC News interview. https://www.bbc.co.uk/news/av/science-environment-46386497
By Heather Godfrey, Fellow IFA Member
Please note this article is subject to copyright, permission must be obtained from the IFA before use and appropriately referenced.
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If you would like to learn more about essential oils please view our course listings and contact an IFA approved course provider. Caution must be exercised when using essential oils and where there is doubt, always contact an IFA Registered Aromatherapist who will offer guidance on the oils that are suitable for individual needs. Our Register is approved by the Professional Standards Authority (PSA), a UK body accountable to Parliament.