Science of Aromatherapy

The Science of Aromatherapy

Aromatherapy is the use of therapeutic oils extracted from trees, bushes, flowers and shrubs from all over the world. In addition, aromatherapy recognizing each oil has its own unique chemical make-up. Recently, aromatherapy tended to be viewed as an art rather than a science. This article has been written by a holistic registered nurse, certified in clinical aromatherapy, for the healthcare professional who wish to acquire unbiased, scientifically based knowledge on the principals and practices of aromatherapy.

What is Aromatherapy?

Science of Aromatherapy

Aromatherapy is the use of therapeutic oils extracted from natural plant matter in order to encourage good health, equilibrium and well-being. Essential oils are naturally forming chemicals that are produced by plants as part of their defense system. Some have antibacterial, antiviral and antifungal properties, others repel insects and herbivores while others attract insects and birds for pollination. Some will seal the leaf or stem if it is broken or damaged while menthol, camphor, cineole types produce a substance that drips off the end of the leaf to prevent plants from growing around them.

The aromatic oils can be found in various parts of the plant including leaves, twigs, stems, roots, flowers, blossoms or fruit. The clove tree, for example, produces different types of oils from its bud, stalk and leaves. The material used, and the art of extraction has developed slowly over the course of time, but the origins reach back to the heart of the earliest civilizations.

Origin of Aromatherapy

Science of Aromatherapy

Aromatic plants and oils have been used for thousands of years in various systems of traditional medicine in ancient civilizations. Of course, plants were the most natural and easily obtainable source of nutrition and most likely, our ancestors noticed which plant juices helped wounds heal faster, abated abdominal cramps, helped you breathe easier or improved your mood. Knowledge of this nature was considered precious and handed down from generation to generation.

The Vedic literature of India dating to around 2000 BC lists over 700 plant substances used for healing including cinnamon, ginger, myrrh, and sandalwood. The Chinese system of medicinal plant usage is evident in the Yellow Emperor’s Book of Internal Medicine  which dates back to 2000 BC, along with the great classic Pen ts’ao kang-mou, which lists over 8,000 thousand plant-based formulas used for healing and wellness even today.

Perhaps the richest association concerning the first aromatic materials used for medicinal purpose are those surrounding the ancient Egyptian civilization. Papyrus manuscripts, dating back to 2800 BC speaks of ‘fine oils and choice perfumes, and the incense of temples, where by every god is gladdened’. Aromatic gums and oils such as Frankincense, Cedar and Myrrh, are still detectable 1000 of years later when tombs were exhumed. Even Hippocrates, the father of medicine, who was born in Greece about 460 BC, also prescribed fumigations and refers to a vast number of medicinal plants in his writings.

In 1928 a French chemist, Rene’ Gattefosse’ coined the phrase aromatherapie. His research was the result of an accident suffered when badly burning his hand while working in his laboratory. He reached for the nearest bowl of liquid, which happened to be Lavender, and was amazed how quickly the hand healed with no sign of scarring. He realized the healing properties of Lavender were much greater than any synthetic, pharmacological preparation, he had been working on and began researching the healing properties of essential oils, taking into consideration their chemical properties as well as their smell.

How Aromatherapy Works

Science of Aromatherapy

Essential oils enter the body in three ways; they can be:

  • Absorbed through the skin and passed through the circulatory system
  • Inhaled passing through the lungs or transmitted via the nervous system directly to the limbic system
  • Ingested (Oral ingestion of essential oils is NOT recommended for the general public because a great deal of essential oils knowledge and expertise is necessary for safe practice.

We have all experienced the undeniable power of aroma. For example, at some point in our lives most of us have all been greeted by a fragrance that triggered a powerful memory such as the smell of freshly baked bread or apple pie conjures up long forgotten childhood memories of your mother.

The response to this type of stimulus is lightning fast; you don’t have time to stop and contemplate what the aroma reminds you of because you are catapulted back in time in a nanosecond, and will often feel a powerful emotional response that can even bring a smile or lead to tears. When this happens, you have just experienced the power of the limbic system in your brain, which mediates and controls all aspects of your emotions, memories, and even your very survival. It also explains how aromatherapy affects your emotions and can link them to memories.

The Science of Aromatherapy: Smell and the Limbic System 101

Science of Aromatherapy

This complex v-shaped structure sits on top of the brain stem and is made up of the hippocampus, amygdala, part of the thalamus and the hypothalamus and several regions of the cerebral cortex. It is one of the earliest parts of the brain to develop in terms of evolution with 34 structures and 53 pathways, and since aromas, emotions, and memories all meet here you see why smell can trigger specific memories and emotions.

The hypothalamus receiving signals and regulating the response to pain, thirst and hunger, levels of pleasure and sexual satisfaction, anger and aggressive behavior, darkness and light. It also regulates the autonomic nervous system which governs your blood pressure, pulse, breathing, digestion, sweating, and arousal in response to emotional circumstances. In many ways the hypothalamus acts like a regulator or thermostat, restoring equilibrium (homeostasis) when the body is out of balance.

Another way the hypothalamus takes control of your body is via its neural and chemical connection to the pituitary gland which in turn receives instructions to release hormones into the body that regulate metabolism and growth. These two organs are key to the way that aromatherapy works.

When used in massage the aromatherapy essential oils have a therapeutic effect through both inhalation and absorption through the skin. The molecules in the oil pass through the epidermis and into the blood stream. Unlike chemicals or drugs, essential oils are typically excreted in 3-6 hours after application.

The Mind-Body Connection

Science of Aromatherapy

When essential oils are use in the treatment of certain conditions either through inhalation, via massage, or used in the bath, they will cause various parts of the limbic system to spring into action. As a result, this triggers the release of neurochemicals and hormones that will slow the heart rate, regulate blood pressure, and stimulate the immune system making one less susceptible to disease or illness.

There are many evidence based research studies that have scientifically proven that essential oils can change mood, behavior and productivity, along with determination of which neurotransmitters were released, thus the mind-body connection which occurs when utilizing aromatherapy. The results of this type of research opens up a mirage of possibilities for future creative medicinal use of essential oils.

“Caveat Emptor” when Purchasing Essential Oils

Science of Aromatherapy

According to the East West School for Herbal and Aromatic Studies, important items to obtain on each essential oil you purchase include:

  • Common name, Latin name (exact genus and species),
  • Country of origin, Part of plant processed,
  • Type of Extraction (distillation or expression),
  • How it was grown (organic, wild-crafted, traditional)
  • Chemotype (when relevant).

Supplier Qualities:

  • One who is dedicated to supplying essential oils to the aromatherapy practitioner market and educated public
  • Owned by an aromatherapy practitioner or essential oil specialist
  • Who has relations with his/her distillers, if possible
  • Who can readily supply a batch-specific GC/MS spec report on each essential oil it sells
  • Readily able to provide material safety data sheets (MSDS) as needed
    • *this is most often needed for individuals who are practicing in a medical facility
  • Who has a strong ethical reputation in the field
  • Who has preferably been in the field for a number of years and is well known to other aromatherapy practitioners and/or educators

 Example of Common Usage of one Essential Oil in Aromatherapy

Lavender (lavendula angustifolia)

The Science of Aromatherapy

Herbal/Folk Tradition: Lavenders scent is a familiar and well established folk remedy in ‘comforting the stomach’, ‘palpations of a nervous sort’, ‘spasms and colic’ and fatigue. Outwardly applied it relieved tooth ache, neuralgia, sprains and rheumatism. The dried flower was carried during the plague to ward off disease.

Actions: Analgesic, antidepressant, antispasmotic, antifungal, antiseptic, sedative, and skin regeneration

Dilution: .25% for children and the elderly to 100% (neat) in adults.

Aromatherapy Use:

  • Skin care: Acne, brittle nails, insect bites and repellent, warts, age spots, alopecia, scarring, burns
  • Circulation, Muscles and Joints: Arthritis, cellulitis, high blood pressure, PMS, poor circulation
  • Respiratory: Asthma, bronchitis, infections of the throat, hay fever
  • Digestive: Irritable bowel, dyspepsia, digestion issues
  • Immune System: Colds, flu, infections
  • Psychological: Anxiety, irritability, nervousness, sleeplessness, anger, exhaustion, dementia


The Science of Aromatherapy

My own interest in essential oils and traditional types of medicine derived from my frustration with modern medicine treatment. This is especially true in treatment for the older population. As a result, they often suffer with aggressive procedures, polypharmacology, dismissal of concerns, and the disease management model of care. Despite a medical systems intent to do the “best work”, it was at odds with my client’s wishes. Many want to “lessen pain,” “die at home,” and “avoid the suffering I have seen my friends go through.” Consequently, finding ways to empower elders and their families in assuring care of the mind, body and spirit of all elders has become my mission. Aromatherapy is one of the ways we can nurture the wholeness of the older adult thereby inspiring peace and healing.

Scientific trials and clinical research has continued to confirm the potentials for using essential oils within the medical arena. Nowadays, aromatherapy treatments are widely available, safely and effectively implemented. Furthermore, they are typically offered in most major hospitals throughout the USA.


If you are a medical individual, Hospital, Hospice, Facility or Home Care Agency interested in learning more about the science of aromatherapy or implementing an aromatherapy program, please call Bobbi at 412-486-6677 or email at

Barbara (Bobbi) Kolonay RN, MS CCM, Certified Holistic Nurse, is the President of Holistic Aging – Options For Elder Care – A Aging Life  Care Management Practice located in Pittsburgh PA.

************ESSENTIAL OILS ARE POTENT and SHOULD NEVER BE INGESTED. Please, take a class and get certified from a medically certified aromatherapist prior to using EO on yourself or others


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Dyer, J. McNeil S, Ragsdale-Lowe M, Tratt, L 2008, A snapshot survey of current practice: the use of aromasticks for symptom management. International Journal of Aromatherapy. 5 (2): 17-21

Lawless, Julia. The Encyclopedia of Essential Oils. San Francisco: Conari Press. 2013. Print

Lis-Balchin, Maria. Aromatherapy Science. London, UK: Pharmaceutical Press. 2006. Print.

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Shutes, Jude. “The Quality of Essential Oils.” The East West School for Herbal and Aromatic Studies. Web. Sept 2014

Walters, Clare. Aromatherapy, An Illustrated Guide. Boston. ELEMENT BOOKS INC. 1998. Print.