What are essential oils?
Essential oils (EOs) are natural liquids that are extracted from various aromatic plants. EOs from different plants contain volatile components, which easily evaporate when exposed to air, and non-volatile components, which do not easily evaporate. (1)(12) EOs are thought to have a variety of medicinal effects, such as anti-cancer, anti-inflammatory, anti-microbial, and anti-viral activity. (1) EOs are often diluted in a carrier oil and used topically in massage therapy or for other therapeutic reasons. EOs can be inhaled by diffusing the oil, which uses a small device to disperse the oil into the air, or by applying a diluted amount to the skin for inhalation. Certain EOs can also be taken internally as dietary supplements. Be sure to verify the essential oil is safe to consume orally before taking any products.
How essential oils work on the brain
Studies have shown that active compounds in EOs are detectable in blood samples following aromatherapy. These compounds may be absorbed through nasal or lung mucosa and can cross the blood-brain barrier due to their small size. (13) The bioactivity of an essential oil refers to the biological effect that the oil, or one of its constituents, demonstrates on animals or humans. (5) The potential effects of essential oils on the brain depend on the specific constituents that are found in the product. For example, lavender (Lavandula angustifolia) essential oil, which is commonly used to address stress and anxiety, contains a compound called linalool, which has been found to have a sedative effect in animal studies. (5)(11)Did you know? Many factors can impact the composition of essential oils, such as the plant variety, growth area, climate changes, harvest period, plant part used, and storage conditions. (5)
Essential oils for brain function
One placebo-controlled study examined the effects of encapsulated organic peppermint (Mentha piperita) EO at doses of 50 µL and 100 µL on cognition and mood. Both doses of peppermint EO were associated with reduced mental fatigue, and the highest dose of peppermint was associated with improved performance on cognitive tasks. The researchers suggest that the increased mental performance may be a result of menthol, a component in the EO, binding to receptors in the nervous system and regulating the availability of acetylcholine, a neurotransmitter involved in cognitive functions such as attention. (9) Another controlled study in healthy adults compared the effects of nightly inhalation of jasmine and lavender EOs on sleep patterns, alertness the following day, and mood and cognitive function in the morning following sleep. Notably, jasmine (Jasminum) EO inhalation was associated with greater sleep efficiency than the control and quicker performance on the cognitive test, as well as lower levels of anxiety and vigor in the morning, suggesting its ability to increase relaxation. Lavender EO inhalation was associated with an elevated mood, though no other effects were observed. (15)Essential oils for brain injury
Brain injury can result from various causes, including physical trauma such as a car accident, toxicity from compounds such as mercury, (17) and certain health conditions such as stroke. (3) Animal studies have investigated the beneficial effects of essential oils for brain damage. In an animal model of ischemia (a type of stroke that blocks the blood supply to the brain), a compound from cinnamon EO called trans-cinnamaldehyde was found to reduce inflammation that damages neuronal (nervous system) cells following stroke. The trans-cinnamaldehyde EO treatment reduced the neurological deficit score and the infarction area (the region with tissue death). (3) Similarly, treatment with Curcuma oil from turmeric (Curcuma longa) rhizomes was associated with decreased cellular death in post-ischemic brains in rats. (4) Furthermore, an active component found in black cumin (Nigella sativa) seed oil known as thymoquinone has demonstrated neuroprotective effects in traumatic brain injury, brain ischemia, and Alzheimer’s and Parkinson’s diseases. Early studies suggest that thymoquinone may downregulate pro-inflammatory signaling molecules, reduce lipid peroxidation (oxidative damage to lipids), and prevent apoptosis (cellular death). (8) While these results are promising, clinical trials in humans are needed to further understand brain injury and essential oils.Essential oils for concussion
A concussion is a type of mild traumatic brain injury that results from a direct or indirect impact to the head. Concussion symptoms include mood disorders, headaches, and sleep disturbances. (14) Current treatment recommendations include cognitive and physical rest, and to date, very little research has been done on essential oils for post-concussion syndrome. (14) However, EOs that can address concussion symptoms or improve rest during recovery, such as lavender and jasmine for relaxation and sleep, (5)(11)(15) may be beneficial. Learn about natural ways to manage a concussion with supplements, including fish oil for concussion, on the Fullscript blog.
Essential oils for brain fog
Brain fog is a cognitive symptom that is commonly described as feeling “cloudy”, “forgetful”, and having “difficulty focusing, thinking, and communicating”. Factors that may contribute to brain fog include fatigue, insufficient sleep, standing for long periods, dehydration, and feeling faint. (16) The best essential oils for brain fog are EOs that address these factors. For example, aromatherapy with lavender essential oil has been shown to increase blood melatonin levels (19) and sleep quality in older adults. (6) Combining lavender EO with sleep hygiene can improve sleep quality and help individuals wake up feeling refreshed, (10) which may benefit brain fog by reducing fatigue.Essential oils for focus and concentration
Studies have shown that the inhalation of fragrances may stimulate or inhibit brain functions. Additionally, research in healthy humans has demonstrated that one of the active compounds found in rosemary (Salvia rosmarinus) oil, 1,8-cineole, is detectable in blood samples following aromatherapy. The level of 1,8-cineole absorbed was positively associated with the speed and accuracy of performance in cognitive tasks such as subtraction exercises and visual information processing. (13)
Essential oils for memory
Another cognitive function that may benefit from the use of essential oils is memory. One placebo-controlled study investigated the effects of Spanish sage (Salvia lavandulaefolia) on memory in healthy young adults. The results showed that an oral dose of 50 μL, taken in capsule form, improved both immediate and delayed word recall. (18) A recent literature review examined the preclinical and clinical trials of various essential oils in Alzheimer’s disease (AD) treatment. Various effects were observed that can potentially impact the pathology of the disease, such as anti-oxidant effects, memory enhancement, and protection against amyloid plaque deposits seen in the brain of individuals with AD. (2) EOs that were found to have some benefit include:- Sage (Salvia officinalis)
- Spanish sage (Salvia officinalis L. ssp. lavandulifolia (vahl))
- Lemon balm (Melissa officinalis)
- Lavender (Lavandula angustifolia)
- Rosemary (Rosmarinis officinalis) (2)
Essential oils for nervous system function
One study in healthy adults examined the effects of various EO fragrances on the sympathetic nervous system, which is the division of the autonomic nervous system that stimulates the body’s stress response, commonly called the “fight or flight response”. When compared to a placebo, the findings indicate that inhalation of tarragon, fennel, grapefruit, and pepper oils stimulate sympathetic activity, while rose and patchouli oils inhibit sympathetic activity. The researchers suggest there are potential applications of EO inhalation in regulating sympathetic nervous system dysfunctions. (7)The bottom line
Essential oils are derived from plants and contain a variety of compounds that may have bioactive effects on the human brain. Preliminary evidence on essential oils and brain health appears promising, however, more studies are needed. If you’re a patient, speak to your practitioner about essential oil supplements or aromatherapy.NEW
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References
- Aziz, Z. A. A., Ahmad, A., Setapar, S. H. M., Karakucuk, A., Azim, M. M., Lokhat, D., Rafatullah, M., Ganash, M., Kamal, M. A., & Ashraf, G. M. (2018). Essential oils: Extraction techniques, pharmaceutical and therapeutic potential – a review. Current Drug Metabolism, 19(13), 1100.
- Benny, A., & Thomas, J. (2018). Essential oils as treatment strategy for Alzheimerʼs disease: Current and future perspectives. Planta Medica, 85(03), 239–248.
- Chen, Y.-F., Wang, Y.-W., Huang, W.-S., Lee, M.-M., Wood, W. G., Leung, Y.-M., & Tsai, H.-Y. (2016). Trans-cinnamaldehyde, an essential oil in cinnamon powder, ameliorates cerebral ischemia-induced brain injury via inhibition of neuroinflammation through attenuation of iNOS, COX-2 expression and NFκ-B signaling pathway. NeuroMolecular Medicine, 18(3), 322–333.
- Dohare, P., Varma, S., & Ray, M. (2008). Curcuma oil modulates the nitric oxide system response to cerebral ischemia/reperfusion injury. Nitric Oxide, 19(1), 1–11.
- Elshafie, H. S., & Camele, I. (2017). An overview of the biological effects of some Mediterranean essential oils on human health. BioMed Research International, 2017, 1–14.
- Faydalı, S., & Çetinkaya, F. (2018). The effect of aromatherapy on sleep quality of elderly people residing in a nursing home. Holistic Nursing Practice, 32(1), 8–16.
- Haze, S., Sakai, K., & Gozu, Y. (2002). Effects of fragrance inhalation on sympathetic activity in normal adults. The Japanese Journal of Pharmacology, 90(3), 247–253.
- Isaev, N. K., Chetverikov, N. S., Stelmashook, E. V., Genrikhs, E. E., Khaspekov, L. G., & Illarioshkin, S. N. (2020). Thymoquinone as a potential neuroprotector in acute and chronic forms of cerebral pathology. Biochemistry (Moscow), 85(2), 167–176.
- Kennedy, D., Okello, E., Chazot, P., Howes, M.-J., Ohiomokhare, S., Jackson, P., Haskell-Ramsay, C., Khan, J., Forster, J., & Wightman, E. (2018). Volatile terpenes and brain function: Investigation of the cognitive and mood effects of Mentha × piperita L. essential oil with in vitro properties relevant to central nervous system function. Nutrients, 10(8), 1029.
- Lillehei, A. S., Halcón, L. L., Savik, K., & Reis, R. (2015). Effect of inhaled lavender and sleep hygiene on self-reported sleep issues: A randomized controlled trial. The Journal of Alternative and Complementary Medicine, 21(7), 430–438.
- Malcolm, B. J., & Tallian, K. (2018). Essential oil of lavender in anxiety disorders: Ready for prime time? The Mental Health Clinician, 7(4), 147–155.
- Merriam-Webster. (n.d.). Volatile oil. In Merriam-Webster. Retrieved October 14, 2020, from https://www.merriam-webster.com/dictionary/volatile%20oil#:~:text=%3A%20an%20oil%20that%20vaporizes%20readily%20especially%20%3A%20essential%20oil
- Moss, M., & Oliver, L. (2012). Plasma 1,8-cineole correlates with cognitive performance following exposure to rosemary essential oil aroma. Therapeutic Advances in Psychopharmacology, 2(3), 103–113.
- Oliver, J. M., Anzalone, A. J., & Turner, S. M. (2018). Protection before impact: The potential neuroprotective role of nutritional supplementation in sports-related head trauma. Sports Medicine, 48(Suppl 1), 39–52.
- Raudenbush, B., Koon, J., Smith, J., & Zoladz, P. R. (2003). Effects of odorant administration on objective and subjective measures of sleep quality, post-sleep mood and alertness, and cognitive performance. North American Journal of Psychology, 5, 181–192.
- Ross, A. J., Medow, M. S., Rowe, P. C., & Stewart, J. M. (2013). What is brain fog? An evaluation of the symptom in postural tachycardia syndrome. Clinical Autonomic Research, 23(6), 305–311.
- Thiagarajan, K., Gamit, N., Mandal, S., Ayyathan, D. M., & Chandrasekaran, R. (2018). Amelioration of methylmercury induced neural damage by essential oil of Selinum vaginatum (Edgew) C. B. Clarke. Pakistan Journal of Pharmaceutical Sciences, 31(2), 399–404.
- Tildesley, N. T. J., Kennedy, D. O., Perry, E. K., Ballard, C. G., Savelev, S., Wesnes, K. A., & Scholey, A. B. (2003). Salvia lavandulaefolia (Spanish Sage) enhances memory in healthy young volunteers. Pharmacology Biochemistry and Behavior, 75(3), 669–674.
- Velasco-Rodríguez, R., Pérez-Hernández, M.G., Maturano-Melgoza, J.A., Hilerio-López, Á., Monroy-Rojas, A., Arana-Gómez, B., & Vásquez, C. (2019). The effect of aromatherapy with lavender (Lavandula angustifolia) on serum melatonin levels. Complementary Therapies in Medicine, 47, 102208.
