Aromatherapy is a derivative of herbal medicine, which is itself a subset of the biological or nature-based complementary and alternative medicine (CAM) therapies. Aromatherapy has been defined as the therapeutic use of essential oils from plants for the improvement of physical, emotional, and spiritual well-being. The proponents of aromatherapy claim it is an all-natural, nontoxic adjunct to conventional medicines.

Essential oils are volatile liquid substances extracted from aromatic plant material by steam distillation or mechanical expression. Oils produced with the aid of chemical solvents are not considered true essential oils, as the solvent residues can alter the purity of the oils themselves and lead to adulteration of the fragrance or to skin irritation.

Essential oils are made up of a large array of chemical components that consist of the secondary metabolites found in various plant materials. The major chemical components of essential oils include terpenes, esters, aldehydes, ketones, alcohols, phenols, and oxides, which are volatile and may produce characteristic odors. Different types of oils contain varying amounts of each of these compounds, which are said to give each oil its particular fragrance and therapeutic characteristics. Different varieties of the same species may have different chemotypes (different chemical composition of the same plant species as a result of different harvesting methods or locations) and thus different types of effects.[1]

Synthetic odors are often made up of many of the same compounds, which are synthesized and combined with other novel odor-producing chemicals. Most aromatherapists believe that synthetic fragrances are inferior to essential oils because they lack natural or vital energy; however, this has been contested by odor psychologists and biochemists.[2]

Aromatherapy is used or claimed to be useful for a vast array of symptoms and conditions. A book on aromatherapy for children suggests aromatherapy remedies for everything from acne to whooping cough.[3] Published studies regarding the uses of aromatherapy have generally focused on its psychological effects (used as a stress reliever or anxiolytic agent) or its use as a topical treatment for skin-related conditions.

A large body of literature has been published on the effects of odors on the human brain and emotions. Some studies have tested the effects of essential oils on mood, alertness, and mental stress in healthy subjects. Other studies investigated the effects of various (usually synthetic) odors on task performance, reaction time, and autonomic parameters or evaluated the direct effects of odors on the brain via electroencephalogram patterns and functional imaging studies.[4] Such studies have consistently shown that odors can produce specific effects on human neuropsychological and autonomic function and that odors can influence mood, perceived health, and arousal. These studies suggest that odors may have therapeutic applications in the context of stressful and adverse psychological conditions.

Practitioners of aromatherapy apply essential oils using several different methods, including direct inhalation via diffuser or drops of oil placed near the patient (e.g., on a pillow); aromatherapy massage, which is the application to the body of essential oils diluted in a carrier oil; and other direct and indirect applications such as placing drops of oil in bathwater, lotions, or dressings. Different aromatherapy practitioners may have different recipes for treating specific illnesses, involving various combinations of oils and methods of application. Differences seem to be practitioner-dependent, with some common uses more accepted throughout the aromatherapy community. Training in aromatherapy is available at several schools throughout the United States and United Kingdom; but there is no professional standardization, and no license is required to practice in either country. Thus, there is not a great deal of consistency in the specific treatments for specific illnesses among practitioners. This lack of standardization has led to poor consistency in research on the effects of aromatherapy: because anecdotal evidence alone or previous experience drives the choice of oils, different researchers often choose different oils when studying the same applications.

Although essential oils are given internally by aromatherapists in France and Germany, their use is generally limited to inhalation or topical application in the United Kingdom and United States. Nonmedical use of essential oils is common in the flavoring and fragrance industries, however, and most essential oils have been classified as GRAS (generally recognized as safe), at specified concentration limits, by the U.S. Food and Drug Administration (FDA).

Aromatherapy products do not need approval by the FDA.

References

1. Wildwood C: The Encyclopedia of Aromatherapy. Rochester, Vt: Healing Arts Press, 1996. 
   
   
2. Dodd GH: The molecular dimension in perfumery. In: Van Toller S, Dodd GH, eds.: Perfumery: The Psychology and Biology of Fragrance. New York, NY: Chapman and Hall, 1988, pp 19-46. 
   
   
3. Worwood VA: Aromatherapy for the Healthy Child: More Than 300 Natural, Non-Toxic, and Fragrant Essential Oil Blends. Novato, Calif: New World Library, 2000. 
   
   
4. Buchbauer G, Jirovetz L, Jäger W, et al.: Fragrance compounds and essential oils with sedative effects upon inhalation. J Pharm Sci 82 (6): 660-4, 1993.  [PUBMED Abstract]
   
   

Glossary Terms

A disorder of the skin in which oil glands and hair glands become inflamed.

A chemical substance found in beer, wine, and liquor. Alcohol is also found in some medicines, mouthwashes, essential oils (scented liquid taken from plants), and household products.

A type of chemical substance made from alcohol. Aldehydes are found in essential oils (scented liquid taken from plants).

A drug used in the treatment of anxiety and muscle spasms.

A type of complementary and alternative medicine that uses plant oils that give off strong pleasant aromas (smells) to promote relaxation, a sense of well-being, and healing.

A type of complementary and alternative medicine that uses rubbing and kneading of the skin with plant oils that give off strong, pleasant aromas (smells) to promote relaxation, a sense of well-being, and healing.

Having an odor, which often is pleasant or spicy.

The state of being alert and ready to respond, or waking from sleep.

A scientist who has special training in the study of the chemicals and processes that occur in all living things.

Pertaining to biology or to life and living things. In medicine, refers to a substance made from a living organism or its products. Biologicals may be used to prevent, diagnose, treat or relieve of symptoms of a disease. For example, antibodies, interleukins, and vaccines are biologicals. Biological also refers to parents and children who are related by blood.

An oil with little or no scent that is used to dilute or “carry” essential oils (scented liquid taken from plants).

CAM. Forms of treatment that are used in addition to (complementary) or instead of (alternative) standard treatments. These practices generally are not considered standard medical approaches. Standard treatments go through a long and careful research process to prove they are safe and effective, but less is known about most types of CAM. CAM may include dietary supplements, megadose vitamins, herbal preparations, special teas, acupuncture, massage therapy, magnet therapy, spiritual healing, and meditation. Also called CAM.

In science, a substance that is made up of more than one ingredient.

A system in which medical doctors and other healthcare professionals (such as nurses, pharmacists, and therapists) treat symptoms and diseases using drugs, radiation, or surgery. Also called Western medicine, mainstream medicine, orthodox medicine, biomedicine, and allopathic medicine.

In chemistry, a compound produced from or related to another.

EEG. A recording of electrical activity in the brain. It is made by placing electrodes on the scalp (the skin covering the top of the head), and impulses are sent to a special machine. An EEG may be used to diagnose brain and sleep disorders. Also called EEG.

The scented liquid taken from certain plants using steam or pressure. Essential oils contain the natural chemicals that give the plant its “essence” (specific odor and flavor). Essential oils are used in perfumes, food flavorings, medicine, and aromatherapy.

A type of chemical substance that is a combination of acid and alcohol. Esters are found in essential oils (scented liquid taken from plants).

In medicine, a preparation of a substance obtained from plants, animals, or bacteria and used as a drug or in drugs.

FDA. An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.

A pleasant, sweet odor.

A noninvasive tool used to observe functioning in the brain or other organs by detecting changes in chemical composition, blood flow, or both.

A type of medicine that uses roots, stems, leaves, flowers, or seeds of plants to improve health, prevent disease, and treat illness.

In medicine, refers to the act of taking a substance into the body by breathing.

A type of chemical substance used in perfumes, paints, solvents, and found in essential oils (scented liquid taken from plants). Ketones are also made by the body when there is not enough insulin.

A substance made when the body breaks down food, drugs or chemicals, or its own tissue (for example, fat or muscle tissue). This process, called metabolism, makes energy and the materials needed for growth, reproduction, and maintaining health. It also helps get rid of toxic substances.

Not harmful or destructive.

A smell.

A type of chemical substance that is a combination of oxygen and another substance. Oxides are found in essential oils.

A very poisonous chemical substance made from tar and also found in some plants and essential oils (scented liquid taken from plants). Phenol is used to make plastics, nylon, epoxy, medicines, and to kill germs. Also called carbolic acid.

A specialist who can talk with patients and their families about emotional and personal matters, and can help them make decisions.

A liquid that is able to dissolve a solid.

Having to do with deep, often religious, feelings and beliefs, including a person’s sense of peace, purpose, connection to others, and beliefs about the meaning of life.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

Having to do with substances that are man-made instead of taken from nature.

A type of strong-smelling chemical substance found in some plants, especially trees that have cones. Terpenes are found in essential oils (scented liquid taken from plants).

Having to do with treating disease and helping healing take place.

Treatment.

On the surface of the body.

Necessary to maintain life. Breathing is a vital function.

A serious bacterial infection of the lungs and breathing tubes that spreads easily. Whooping cough begins like a cold, but develops into severe coughing and gasping for air. Long spells of coughing may cause vomiting, and broken blood vessels in the eyes and on the skin. Also called pertussis.