Why are Essential Oils loved? Compelling studies validate the science of these sought-after aromas
Updated: Jul 10, 2021
Essential OIls are fast replacing, synthetic aroma chemicals in cosmetics, soaps, perfumes and home cleaning products.
It is almost a trend to treat simple discomforts like headaches, insomnia, fatigue, aches/spasms, flu and even dandruff/acne with Essential Oils.
Whats more, some essential oils like Rosemary, Frankincense, Lavender are even touted as a cure for serious issues like cancer, tumours, diabetes, alzheimers and nerve realted inflammation and disorders
Champions of natural products seem to be waxing eloquent about how much wellness Aromatherapy Or Essential Oils bring to the body, mind and the soul!
Are these claims justified? Has enough research been done to back these claims? Lets dive right in . In this post we will discuss:
Essential oils are the ‘essence’ – the compounds, extracted from plant parts- present in them to ward off environmental threats.
These oil rich parts such as the rind, flowers, bark, leaves etc are usually the ones attacked by microorganisms.
Variance in these compounds gives each plant a specific scent.
These fragrant oils, extracted by steam/hydro distillation or by cold-press processing are called Essential oils.
B. How can these humble plant oils (Essential Oils) affect a person's mind, body and wellness??!
Everyone knows that our sense of smell can powerfully move us. But how?
Well, as per Levenson (2018) Aromas can access centres that control the emotional sphere whose importance, for both mental and physical health, is established.
Simply put, it means this.
When a person inhales an aroma that scent is carried by olfactory nerve cells in the nose to the olfactory system. This system then transmits the aroma to the brain’s limbic system (the house of emotions).
As per Damasio (2005) the limbic system impacts emotional reactions.
It jumpstarts the unconscious part of our emotions, especially after an aromatic stimulus, and sends impulses to the cortex that controls how we react physically and behaviourally.
(C) Studies on Essential Oil aroma-impact on the Brain, Nervous, Endocrine system
Pardon the jargon, we have tried to simplify these long scientific terms.
Studies 1, 2, 3,4,5,6,7, 8,9 show how Essential oil aromas, after travelling through the olfactory system can influence:
· The Sympathetic nervous system
o The Urgent responses of the Nervous system
· The Parasympathetic nervous system
o The Restful responses of the Nervous system
· The Neurophysiological brain activity:
o The activity of brain nerve cells as they receive and transmit information.
· The Neuroendocrine system:
o The interactions between the Nervous and Endocrine systems.
o The chemical transmitters that send signals from one neuron to another OR to a muscle or a gland cell
These, in turn impacts the Body/Mind of the Users.
D. Studies that have used sophisticated medical devices to test the impact of Essential Oils on the Brain/Body/Emotions
Studies 10,11,12,13,14,15,16 assessed the emotional impact of Essential Oil aromas using sophisticated means like:
· Electroencephalogram (EEG)
A test that checks the electrical activity in the brain
· Near infrared spectroscopy (NIRS)
A technique that uses light waves in the red and near-infrared (NIR) ranges of the light spectrum to monitor changes in oxygen and blood volume levels in human tissue.)
· Functional magnetic resonance imaging (FMRI)
A non-invasive brain imaging method, used in cognitive neuro- science
(E) Benefit specific Research on Essential Oils
(a) Studies on Essential oils and Stress, Anxiety
Some studies have shown that the aroma of some essential oils work well as a complementary therapy for anxiety and stress 35, 36, 37
· Masago 15 recorded that essential oil inhalation changed alpha wave brain activity (alpha waves are brain waves in a state of wakeful rest).
· Manley 17 studied CNV (contingent negative variation- reaction time between warning and a go-signal) effects of Essential oil aromas: some increased CNV amplitude (stimulating effect), while others decreased them (relaxing effect), and yet others were inconclusive
· Employing NIRS, Tanida 18 studied the effects of aromas on the Pre‐frontal cortex (PFC) brain activity- its key function being to control our emotional response to stress.
Inhaling Essential oil aromas altered the dominant side of the PFC activity which means it helped re-establish equilibrium from the damaging effects of stress.
· Haze 19used fluctuations in blood pressure and adrenaline concentration to study the effects of essential oils.
He recorded that Essential oils, Peppermint and Grapefruit increased the sympathetic activity by 1.5 to 2.5 times (1.7 times increase in adrenaline) whereas Rose or Patchouli Essential oils caused a 40% decrease in sympathetic activity (a 30% decrease in adrenaline)
· A study conducted by Heuberger and Höferl 20,21, concluded that aroma inhalation influences autonomic nervous system as well as mental and emotional conditions
(b) Studies on Essential oils and Headaches
Studies have shown inhaling peppermint and lavender oil can give substantial relief from headaches40, 41
(c) Studies on Essential oils and Sleep/ Insomnia
A study 44 conducted on 15 different essential oils showed their positive effects (particularly lavender essential oil) on sleep.
Inhalation of lavender oils also improved the sleep quality in patients with heart disease as well as on post-partum women. 42,43
(e) Studies on Essential oils as antimicrobial, antibacterial, antiviral agents
Essential oils such as Peppermint essential oils and Tea Tree essential oils have been tested for fighting bacterial infections with encouraging results 49, 50, 51,52,53,54,55,56,57
(f) Studies on Essential oils for healthy hair/skin
Because essential oils have low molecular weights and are lipid(fat) soluble, they easily penetrate the skin, hair follicles. Once absorbed, they stay in the applied area for a localized benefit
· Stress affects skin and hair. Hence Essential oils that regulate stress can help treat stress damaged hair or skin27,28.
· Essential oil aromas also affect the neuroendocrine system. Hormones if positively managed with essential oils can positively impact skin and hair functions 29,30.
· A study 31 has found a co -relationship between oxidative stress and essential oil aroma inhalation. Oxidative stress is an imbalance between free radicals and antioxidants in the body. Free radicals attack biological molecules such as lipids, proteins DNA etc. damaging skin and hair.
Antioxidants that protect the cells from free radicals, increased with lavender and rosemary inhalation and protects skin, hair from oxidative stress.
· Skin (Cutaneous) barrier function is essential for healthy skin as it keeps the skin hydrated, prevents fissures and protects it from infections. Disruption of this barrier function or skin dehydration can lead to skin diseases.
Stress delays the recovery of cutaneous barrier after disruption.
Denda’s study 33, 34 shows that inhalation of sedative essential oils such as Rose essential oil accelerates this barrier recovery in humans.
(F) A summary of study-backed benefits of Essential Oils
· Promote an overall sense of well being
· Reduce anxiety and stress.
· Induce relaxation and a feeling of wellbeing
· Improve the quality of sleep
· Relieve headaches and migraines
· Bring about clarity and better concentration
· Kill fungus, bacteria and virus.
· Ease discomforts of menstruation, menopause and labor.
· Relieve of general pains such as muscle ache, joint pain, back pain, spasms etc
· Citronella, Lemongrass, Tea Tree, Lemon, Peppermint, Eucalyptus Essential oils are famously used as natural bug repellents. Citronella Essential oil has been identified as an environment friendly option against DEET giving protection against insects for as long as 2 hours.
· Essential oils are being used for home deodorising or laundry freshening.
· They are used as a natural deodorant. Many DIY chemical free home- made lotions, creams etc are being formulated using essential oils.
Further progress in scientific studies might fully demystify the effects of Essential oils to the very last detail.
10 Most Popular Essential oils, their Benefits, What to use them for and how to use them
There are over a hundred kinds of Essential oils, each with their unique aroma and distinctive benefits.
Blend Essential oils always with carrier oils for topical application.
Go for Argan Oil, Jojoba Oil, Sweet Almond Oil, Coconut Oil, Grapeseed Oil, Apricot Kernel oil, Avocado Oil, Borage seed oil, Wheat Germ oil, Rosehip Oil for their wonderful goodness. Read more about Carrier Oils
1.Peppermint Essential Oil (Mentha Piperita)
· Diffuse to boost energy and relieve stress.
· Apply diluted on temples to alleviate headaches, travel sickness
· Diffuse as an expectorant and decongestant
· Apply diluted or cold compress to dulls muscle pain/cramps
· Diffuse to clear mind and concentrate.
· Add a few drops to warm water for a foot bath for sore feet
· Add a couple of drops to your favourite shampoo/ hair oil for cooling anti-dandruff effects.
· Spritz diluted for repellent and anti-bacterial properties.
· Rub a few diluted drops on abdomen for digestion or to relieve flatulence.
2.Lavender Essential Oil (Lavandula Angustfolia)
· Diffuse to relieve stress and anxiety
· Diffuse to improve mood
· Diffuse to relieve headaches
· Diffuse to battle insomnia
· Spritz diluted to freshen air or deodorize
· Add a drop to 10 ml of your favourite carrier oil/ cream or lotion and massage regularly for rejuvenated skin
· Add to a drop to your favourite hair oil for healthier hair
· Mixed with grapeseed oil, it can treat bites and burns.
· Diffuse for relief from flu
· Add a few drops to bath water to ease sore muscles
3.Eucalyptus Essential Oil (Eucalyptus Radiata)
· Diffuse to boost energy and relieve stress.
· Diffuse for anti-viral properties as an expectorant and decongestant
· Diffuse for relief from sinus headaches
· Apply diluted or cold compress to dulls muscle pain/cramps
· Diffuse to clear mind and concentrate.
· Spritz diluted for anti-bacterial repellent effect.
4.Geranium Essential Oil (Pelargonium Graveolens)
· Diffuse to ward off feeling blue.
· Diffuse to relive stress, anxiety, restlessness
· Spritz diluted as a deodorant.
· Add a drop to 10 ml carrier oil and massage your body OR add a Few drops to your bath for relief from pain in the nerves.
· Diffuse for a balancing effect on the hormones or for relief from pre-menstrual tension or even menopause.
· Spritz diluted as a mosquito repellent and home deodoriser.
5.Sandalwood Essential Oil: (Santalum album)
· Diffuse to calm nerves and sharpen focus.
· Blend with a carrier oil and use on body as an anti-ageing serum. Works to close open pores as an astringent too.
· Use diluted topically or as a cold compress for its anti-spasmodic properties and anti-inflammatory properties.
6.Rosemary Essential Oil (Rosmarinus Officinalis)
· Diffuse for sharp focus and concentration
· Dilute with your favourite hair oil or carrier oil for hair growth
· Diffuse to ease cold and cough
· Diffuse to improve memory power.
· Diffuse to reduce cholesterol.
· Use as a cold compress for muscle ache relief.
7.Rose Essential Oil (Rosa Damascena)
· Diffuse to cheer up the mood, can help alleviate melancholy and grief.
· Diffuse to reduce mental fatigue, stress and anxiety
· Diffuse to balance hormones
· Diffuse to balance blood pressure.
· Diffuse or spritz diluted for its highly antiseptic properties.
· Diffuse to cheer up mood, promote calm and relaxation
· Diffuse for balancing hormones and relief from pre-menstrual syndrome
· Diffuse to get a restful sleep and handle insomnia
· Diffuse for headache relief
· Use as a cold compress to relieve pain, inflammations and spasms.
· Use diluted with your favourite carrier oil for healthy skin. If skin is dry then blend with sandalwood essential oil and carrier oil for topical application.
· Diffuse to create a soothing atmosphere.
9.Tea Tree Essential Oil (Melaleuca alternifolia):
· Diffuse to boost immunity, fight infections.
· Diffuse for clear mind and focus.
· Spritz diluted as a deodoriser, anti-bacterial insect repellent.
· Apply diluted topically with your favourite carrier oil to treat acne and skin infections.
· Apply diluted with your favourite hair oil to treat dandruff and wash off with tea- tree blended shampoo.
· Use diluted for its antifungal and antiseptic properties
10.Lemon Essential oil (Citrus Limon)
· Diffuse for a cheerful vibrant mood
· Spritz diluted for its anti-bacterial, deodorizing, insect repelling effects.
· Use diluted in your favourite hair and body cleaner
· Diffuse to control binge eating
· Diffuse to boost immunity
· Diffuse for relief from cold and flus.
1.Angelucci F.L., Silva V.V., Dal Pizzol C., Spir L.G., Praes C.E., Maibach H. Physiological effect of olfactory stimuli inhalation in humans: An overview. Int. J. Cosmet. Sci. 2014;36:117–123. doi: 10.1111/ics.12096. [PubMed] [CrossRef] [Google Scholar]
2. Diego M.A., Jones N.A., Field T., Hernandez-Reif M., Schanberg S., Kuhn C., McAdam V., Galamaga R., Galamaga M. Aromatherapy positively affects mood, EEG patterns of alertness and math computations. Int. J. Neurosci. 1998;96:217–224. doi: 10.3109/00207459808986469. [PubMed] [CrossRef] [Google Scholar]
3.Strous, R.D. and Shoenfeld, Y. To smell the immune system: olfaction, autoimmunity and brain involvement. Autoimmun. Rev.6, 54–60 (2006).5Kiecolt‐Glaser, J.K., Graham, J.E., Malarkey, W.B. et al. Olfactory influences on mood and autonomic, endocrine, and immune function. Psychoneuroendocrinology33, 328–339 (2008).
4.Fukui, H., Toyoshima, K. and Komaki, R. Psychological and neuroendocrinological effects of Patchouli. Neurosci. Res.65, S222 (2009).
5. Goel, N., Kim, H. and Lao, R.P. An olfactory stimulus modifies nighttime sleep in young men and women. Chronobiol. Int.22, 889–904 (2006).
CM Owen, J Patterson - Food quality and preference, 2002 - Elsevier
14.Sayowan, W., Siripornpanich, V., Piriyapunyaporn, T. et al. The effects of lavender oil inhalation on emotional states, autonomic nervous system, and brain electrical activity. J. Med. Assoc. Thai.95, 4 (2012).
15.Masago, R., Matsuda, T., Kikuchi, Y. et al. Effects of inhalation of essential oils on EEG activity and sensory evaluation. J. Physiol. Anthropol.19, 35–42 (2000).
18.Tanida, M., Katsuyama, M. and Sakatani, K. Effects of fragrance administration on stress‐induced prefrontal cortex activity and sebum secretion in the facial skin. Neurosci. Lett.432, 157–161 (2008).
22.Cilia, A.T. and Kang, R.K.L. The Influence of Fragrance on Salivary Alpha‐Amylase and Cortisol reactivity to acute stress. a pilot study. Proceedings of the Association of Chemoreception Science (AChemS), California, USA, (2012).
23.Yamaguchi, M., Hanawa, N., Hamazaki, K. et al. Evaluation of the acute sedative effect of fragrances based on a biochemical marker. J. Essent. Oil Res.19, 470–476 (2007).
24.Yamaguchi, M., Tahara, Y. and Kosaka, S. Influence of concentration of fragrances on salivary alpha‐amylase. Int. J. Cosmet. Sci.31, 391–395 (2009).
25.Fukui, H., Toyoshima, K. and Komaki, R. Psychological and neuroendocrinological effects of Patchouli. Neurosci. Res.65, S222 (2009).
26. Fukada, M., Kano, E., Miyoshi, M. et al. Effect of “rose essential oil” inhalation on stress‐induced skin‐barrier disruption in rats and humans. Chem. Senses37(4), 347–356 (2012).
27.Hosoi, J. Stress and the skin. Int. J. Cosmet. Sci.28, 243–246 (2006).
28. Gieler, U., Kupfer, J., Niemeier, V. and Brosig, B. Psyche and skin: What's new? J. Eur. Acad. Dermatol. Venereol.17, 155–159 (2003).
29. Makrantonaki, E., Schönknecht, P., Hossini, A.M. et al. Skin and brain age together: the role of hormones in the ageing process. Exp. Gerontol.45, 801–813 (2010).
30. Roth, G.S. and Hess, G.D. Changes in the mechanisms of hormone and neurotransmitter action during aging: current status of the role of receptor and post‐receptor alterations. Mech. Ageing Dev.20, 175–194 (1982).
31 Atsumi, T. and Tonosaki, K. Smelling lavender and rosemary increases free radical scavenging activity and decreases cortisol level in saliva. Psychiatry Res.150, 89–96 (2007).
32. Ropke, C.D., da Silva, V.V., Kera, C.Z. et al. In vitro and in vivo inhibition of skin matrix metalloproteinases by Pothomorphe umbellata root extract. Photochem. Photobiol.82, 439–442 (2006).
33.Denda, M., Tsuchiya, T., Shoji, K. and Tanida, M. Odorant inhalation affects skin barrier homeostasis in mice and humans. Br. J. Dermatol.142, 1007–1010 (2000).
34. Fukada, M., Kano, E., Miyoshi, M. et al. Effect of “rose essential oil” inhalation on stress‐induced skin‐barrier disruption in rats and humans. Chem. Senses37(4), 347–356 (2012).
35. 2012 Jul 31.
Effect of sweet orange aroma on experimental anxiety in humans
Screening of five essential oils for identification of potential inhibitors of IL-1-induced Nf-kappaB activation and NO production in human chondrocytes: characterization of the inhibitory activity of alpha-pinene