Flowery fragrance proves relaxing in new lab and clinical studies 11/19/2018
When you hold your nose to a flower or culinary herb, the fragrance you sense comes from so-called “essential oils”.
As well as emitting wonderful aromas, there’s growing evidence that essential oils can also exert mood-changing and relaxing effects.
Two recently published studies — one in mice and one in people — examined the effects of lavender essential oil on symptoms of anxiety.
And both studies found that this simple scent exerts significant calming effects — without the adverse side effects or addictive potential associated with anti-anxiety drugs like Valium and Prozac.
Before we get to those studies, let’s take a quick look at the origins and chemistry of essential oils, and how they affect the brain — very directly, as it turns out.
What are essential oils and how are they used?
Essential oils occur in the flowers, roots, seeds, stems, and bark of plants.
They produce essential oils to perform a variety of functions, from defense against microbes and insects to hormone-like mediation of metabolic processes.
Unlike vegetable oils, which consist entirely of fatty acids, essential oils consist largely of “volatile” — i.e., penetrating and fast-evaporating — hydrocarbons such as terpenes, alcohols, esters, lactones, acids, ketones, and aldehydes.
And it’s no exaggeration to say that essential oils have the power to change your mind and mood.
That’s because the olfactory bulb — the seat of our sense of smell and the only brain structure that extends beyond the skull — is an extension of the brain’s limbic system.
More specifically, the olfactory bulb occurs in a brain structure called the rhinencephalon — a scientific term meaning “smell brain” — which extends into your nasal passage.
The limbic system also contains the hippocampus, which is critical to memory — a fact that may partly explain why smells can trigger memories.
In addition to memory, the limbic system plays a key role in controlling digestion, sexual response, and emotions — which helps explain why smells can impact your mood and libido.
To fragrance a room — whether to create a pleasant scent or for so-called aromatherapy — essential oils are dispersed via candles or diffusion devices.
Or, essential oils can be added — typically in very small quantities — to bath water or topical oils and lotions, simply to add a scent or for aromatherapeutic purposes.
Essential oils occur at very low concentrations in plants, so they must be highly concentrated to exude a powerful fragrance and significantly affect the brain or skin.
For example, it takes 220 pounds of lavender flowers to create about 1 pound of lavender oil — which explains why genuine, undiluted essential oils aren’t cheap and why a little goes a long way!
Lavender’s relaxing reputation and record
Lavender essential oil has long been used to calm and soothe the nerves, thereby relieving anxiety and easing users into a good night’s sleep.
Scientific researchers are just beginning to explore the potential uses of essential oils as replacements for the primary but problematic anti-anxiety drugs: selective serotonin reuptake inhibitors (SSRIs) like Prozac or Zoloft and benzodiazepines (BDZs) such Diazepam, which is better known as Valium.
While these drugs can certainly ease anxiety, they can also cause headaches, drowsiness, dizziness, sexual dysfunction, abuse, dependence, and significant sedation.
The results of prior research showed that lavender can be an effective relaxant, without the risk of side effects (Cline M et al. 2008; Souto-Maior FN et al. 2011; Rahmati B et al. 2017).
Lavender mimicked Valium in mice, without side effects
A terpene-type alcohol called linalool occurs in the essential oils of some 200 plants, including lavender, cinnamon, basil, cannabis, laurel, and mint.
A recent Japanese study in mice was designed to test whether the smell of linalool could induce relaxation, and whether its effects on the brain resemble those of the Valium.
Affirming the findings of prior research, the results confirmed that anxiety was eased in the animals that inhaled lavender-derived linalool (Harada H et al. 2018).
Critically, those relaxing effects stemmed from inhaling the fragrance compound, not from linalool in the bloodstream.
And the researchers found that inhaled linalool affected the same parts of the animals’ brains affected by Valium — without exerting the sedating effects associated with the drug.
Proving that inhaling the scent was responsible for the benefit, lavender-derived linalool was no longer effective if the team blocked the mice’s ability to smell or gave the mice a drug that blocks smell receptors in the brain.
Their findings suggest that linalool affects odor-sensitive neurons in the olfactory bulb, which in turn send “you can relax” signals to the same brain areas effected by benzodiazepine drugs such as Valium.
Study co-author Dr. Hideki Kashiwadani stressed that key point: “When combined, these results suggest that linalool does not act directly on GABAA receptors like benzodiazepines do — but must activate them via olfactory neurons in the nose in order to produce its relaxing effects.”
However, an earlier Brazilian study found that lavender essential oil eased anxiety in mice via the same mechanisms affected by SSRI drugs like Prozac or Zoloft (Chioca LR et al. 2013).
And a study by US Army researchers found that lavender-derived linalool did not act on the receptors affected by Valium and other benzodiazepines (Cline M et al. 2008).
So, lavender essential oil may exert broad-spectrum anti-anxiety effects that mimic the beneficial brain effects of diazepam drugs like Valium and SSRIs like Prozac or Zoloft — without their adverse side effects.
Lavender may ease pre-surgical anxiety
Another recent study tested whether lavender aromatherapy could ease anxiety before surgery.
Previous research has shown that pre-operative anxiety can reduce a patient’s satisfaction with the procedure and worsen their surgical outcomes.
Pre-operative anxiety is also linked to greater use of narcotics and anesthetics, longer hospital stays, more drawn-out postoperative wound healing, and an impaired ability to fight infections.
While sedatives and opioids can ease pre-operative anxiety, they come with a range of negative side effects, including fatigue, confusion, restlessness — and the potential for addiction.
So, New York-based researchers wanted to see whether lavender could provide a low-risk, simple, cost-effective method of managing pre-operative anxiety.
The research team recruited 100 patients who were scheduled to undergo some sort of ear-nose-throat surgery at New York‐Presbyterian/Weill Cornell Medical Center.
Half the patients were given a lavender aromatherapy patch to place on their gowns before surgery, which would diffuse a mild scent. The other half, the control group, received no aromatherapy before surgery.
Before surgery, the volunteers all took a test that measures their anxiety on a 10-point scale, ranging from no anxiety to high anxiety. Each of the patients took the test twice: once when they arrived at the waiting area, and again before they left for the operating room.
Encouragingly, the results showed modestly lower anxiety levels in the lavender-patch group, most of whom reported feeling calmer and found the lavender scent pleasant.
As the study’s senior author, Ashutosh Kacker, MD, said, “Given the simplicity, safety, and cost-effectiveness of aromatherapy, healthcare providers should consider its use for managing this common problem.”
- Chioca LR, Ferro MM, Baretta IP, Oliveira SM, Silva CR, Ferreira J, Losso EM, Andreatini R. Anxiolytic-like effect of lavender essential oil inhalation in mice: participation of serotonergic but not GABAA/benzodiazepine neurotransmission. J Ethnopharmacol. 2013 May 20;147(2):412-8. doi: 10.1016/j.jep.2013.03.028. Epub 2013 Mar 22
- Cline M, Taylor JE, Flores J, Bracken S, McCall S, Ceremuga TE. Investigation of the anxiolytic effects of linalool, a lavender extract, in the male Sprague-Dawley rat. AANA J. 2008 Feb;76(1):47-52.
- Harada H, Kashiwadani H, Kanmura Y, Kuwaki T. Linalool Odor-Induced Anxiolytic Effects in Mice. Front Behav Neurosci. 2018;12:241. Published 2018 Oct 23. doi:10.3389/fnbeh.2018.00241
- Klein J. Lavender's Soothing Scent Could Be More Than Just Folk Medicine. The New York Times, 23 Oct. 2018, www.nytimes.com/2018/10/23/science/lavender-scent-anxiety.html
- López V, Nielsen B, Solas M, Ramírez MJ, Jäger AK. Exploring Pharmacological Mechanisms of Lavender (Lavandula angustifolia) Essential Oil on Central Nervous System Targets. Front Pharmacol. 2017 May 19;8:280. doi: 10.3389/fphar.2017.00280. eCollection 2017.
- Perry R, Terry R, Watson LK, Ernst E. Is lavender an anxiolytic drug? A systematic review of randomised clinical trials. Phytomedicine. 2012 Jun 15;19(8-9):825-35. doi: 10.1016/j.phymed.2012.02.013. Epub 2012 Mar 29. Review.
- Rahmati B, Kiasalari Z, Roghani M, Khalili M, Ansari F. Antidepressant and anxiolytic activity of Lavandula officinalis aerial parts hydroalcoholic extract in scopolamine-treated rats. Pharm Biol. 2017 Dec;55(1):958-965. doi: 10.1080/13880209.2017.1285320.
- Souto-Maior FN, de Carvalho FL, de Morais LC, Netto SM, de Sousa DP, de Almeida RN. Anxiolytic-like effects of inhaled linalool oxide in experimental mouse anxiety models. Pharmacol Biochem Behav. 2011 Dec;100(2):259-63. doi: 10.1016/j.pbb.2011.08.029. Epub 2011 Sep 10.
- Wotman M, Levinger J, Leung L, Kallush A, Mauer E, Kacker A. The Efficacy of Lavender Aromatherapy in Reducing Preoperative Anxiety in Ambulatory Surgery Patients Undergoing Procedures in General Otolaryngology. Laryngoscope Investig Otolaryngol. 2017;2(6):437-441. Published 2017 Nov 8. doi:10.1002/lio2.121