Aromatherapy is a form of
alternative medicine that uses volatile plant materials, known as
essential oils, and similar aromatic compounds from plants, for the purpose of improving a person's mood, cognitive function or health. Preliminary scientific evidence is growing in all these areas. An aroma therapist is the person who performs the aromatherapy.
Aromatherapy is a generic term. It is used by manufacturers (of personal care, wellness and hygiene products) as well as practitioners, including
massage therapists,
chiropractors,
nurses and
doctors.
Over-the-counter products that make use of essential oils (or their constituents, such as menthol and methyl salicylate) include
mouthwashes,
liniments and "rubbing ointments", such as
Listerine,
Mentholatum Deep Heat and
Vicks VapoRub. However, aromatherapy purists insist that neither essential oil constituents as such, nor synthetic fragrant chemicals, should ever be used.
Because many essential oils are potent antimicrobials, they can be useful in the treatment of infectious disease. They are used as medicines, often in combination with other herbal preparations, by a small group of doctors in France. In nursing, essential oils are increasingly used in pain management, anxiety/depression, and
Alzheimer's disease. Aromatherapy may be used in combination with other forms of
alternative medicine. Terms such as 'essential oil therapy' 'clinical aromatherapy' and 'medical aromatherapy' have been used by some journals, educational institutions and practitioners, in order to distance themselves from association with the commercial aspects.
History
Aromatherapy has origins in antiquity with the use of infused aromatic oils, made by macerating dried plant material in fatty oil, heating and then filtering. Many such oils, and their healing properties, are described by
Dioscorides in his
De Materia Medica, written in the first century. Distilled essential oils have been employed as medicines since the invention of
distillation in the eleventh century, when
Avicenna isolated essential oils using
steam distillation.
[Marlene Ericksen (2000), Healing with Aromatherapy, p. 9, McGraw-Hill Professional, ISBN 0658003828]The concept of aromatherapy was first mooted by a small number of European scientists and doctors, in about 1907. In 1937, the word first appeared in print in a French book on the subject:
Aromathérapie: Les Huiles Essentielles, Hormones Végétales by , a chemist. An English version was published in 1993. In 1910, Gattefossé burned a hand very badly in a laboratory explosion. The hand developed
gas gangrene, which he successfully, and intentionally, treated with lavender oil. This helped greatly to fire an already existing interest in aromatherapy, though it was not the "lucky accident" that is sometimes recounted by others.
A French surgeon, , pioneered the medicinal uses of essential oils, which he used as antiseptics in the treatment of wounded soldiers during
World War II.
Modes of application
The modes of application of aromatherapy include:
- Aerial diffusion: for environmental fragrancing or aerial disinfection
- Direct inhalation: for respiratory disinfection, decongestion, expectoration as well as psychological effects
- Topical applications: for general massage, baths, compresses, therapeutic skin care
Materials
Some of the materials employed include:
- Absolutes: Fragrant oils extracted primarily from flowers or delicate plant tissues through solvent or supercritical fluid extraction (e.g. rose absolute). The term is also used to describe oils extracted from fragrant butters, concretes, and enfleurage pommades using ethanol.
Theory
Aromatherapy is the treatment or prevention of disease by use of
essential oils. Two basic mechanisms are offered to explain the purported effects. One is the influence of aroma on the
brain, especially the
limbic system through the
olfactory system. The other is the direct pharmacological effects of the
essential oils. While precise knowledge of the
synergy between the body and aromatic oils is often claimed by aromatherapists, the efficacy of aromatherapy remains to be proven. However, some preliminary clinical studies show positive effects.
In the English-speaking world, practitioners tend to emphasize the use of oils in massage. Aromatherapy tends to be regarded as a complementary modality at best and a
pseudoscientific fraud at worst.
On the continent, especially in
France, where it originated, aromatherapy is incorporated into mainstream medicine. There, the use of the antiseptic, antiviral, antifungal, and antibacterial properties of oils in the control of infections is emphasized over the approaches familiar to North Americans. In France some essential oils are regulated as
prescription drugs, and thus administered by a
physician. French doctors use a technique called the aromatogram to guide their decision on which essential oil to use. First the doctor cultures a sample of infected tissue or secretion from the patient. Next the growing culture is divided among
petri dishes supplied with
agar. Each petri dish is inoculated with a different essential oil to determine which have the most activity against the target strain of microorganism. The antiseptic activity manifests as a pattern of inhibited growth.
In many countries, essential oils are included in the national
pharmacopoeia, but aromatherapy as science has never been recognized as a valid branch of medicine in the
United States,
Russia,
Germany, or
Japan.
Essential oils (EOs), phytoncides, and other natural
VOCs work in different ways. At the scent level they activate the
limbic system and emotional centers of the
brain. When applied to the skin (commonly in form of "massage oils," i.e., 1%–10% solutions of EO in carrier oil) they activate thermal receptors and kill microbes and fungi. Internal application of essential oil preparations (mainly in pharmacological drugs; generally not recommended for home use apart from dilution—1%–5% in fats or mineral oils, or hydrosoles) may stimulate the
immune system.
Choice and purchase
Oils with standardized content of components (marked FCC, for Food Chemical Codex) have to contain a specified amount of certain aroma chemicals that normally occur in the oil. But there is no law that the chemicals cannot be added in synthetic form in order to meet the criteria established by the FCC for that oil. For instance,
lemongrass essential oil has to contain 75%
aldehyde to meet the FCC profile for that oil, but that aldehyde can come from a chemical refinery instead of from lemongrass. To say that FCC oils are "food grade" then makes them seem natural when in fact they are not necessarily so.
Undiluted essential oils suitable for aromatherapy are termed
therapeutic grade, but in countries where the industry is not regulated, therapeutic grade is based on industry consensus and is not a regulatory category. Some aromatherapists take advantage of this situation to make misleading claims about the origin and even content of the oils they use. Likewise, claims that an oil's purity is vetted by
mass spectrometry or
gas chromatography have limited value, since all such testing can do is show that various chemicals occur in the oil. Many of the chemicals that occur naturally in essential oils are manufactured by the perfume industry and adulterate essential oils because they are cheaper. There is no way to distinguish between these synthetic additives and the naturally occurring chemicals.
The best instrument for determining whether an essential oil is adulterated is an educated nose. Many people can distinguish between natural and synthetic scents, but it takes experience.
Price
Oils vary in price based on the amount of the harvest, the country of origin, the type of extraction used (steam distillation, CO
2 extract,
enfleurage), and how desirable the oil is. Indian Sandalwood (
Santalum album) is considered more desirable than Australian Sandalwood (
Santalum spicatum), based upon the aroma, and is twice as costly, mainly because the tree that yields Indian Sandalwood essential oils is endangered, and because S. Spicatum essential oil contains only about 17% α-santalol and 7% β-santalol - much less than S. Album oil. Organic and wild harvested essential oils also tend to be more expensive.
Price is also determined by whether the oil is 'cut' or not. There are few companies and individuals that produce then resell 'pure', unadulterated essential oils. Many times oils are extracted, by whatever form, then repressed or thinned with a carrier of alcohol or some such substance. This lowers the quality of the healing properties of the oils. It can also lower the price necessary for a profit to be made, especially with higher priced oils such as rose or frankinscense.
Pharmacological effects attributed to essential oils
- Antispasmotic (spasmolytic): Spasmolytic properties for catnip, lavender and New Zealand tea tree oils have been reported in animal studies.
Popular uses
- Basil is used in perfumery for its clear, sweet and mildly spicy aroma. In aromatherapy, it is used for sharpening sexual concentration, for its uplifting effect on depression, and to relieve headaches and migraines. Basil oil has many chemotypes and some are known to be emmenagogues and should be avoided during pregnancy.
- Bergamot is one of the most popular oils in perfumery. It is an excellent insect repellent and may be helpful for both the urinary tract and for the digestive tract. It is useful for skin conditions linked to stress, such as cold sores and chicken pox, especially when combined with eucalyptus oil. Bergamot is a flavoring agent in Earl Grey tea. Cold-pressed Bergamot oil contains bergaptene, a strong photosensitizer when applied to the skin, so only distilled or 'bergaptene-free' types can be topically used.
- Black pepper has a sharp and spicy aroma. Common uses include stimulating the circulation and for muscular aches and pains. Skin application is useful for bruises, since it stimulates the circulation.
- Geranium oil is used as an astringent, antiseptic and diuretic.
- Lavender oil is used as an antiseptic, to soothe minor cuts and burns, to calm and relax, for insomnia and to soothe headaches and migraines.
- Lemon oil is uplifting and anti-stress/anti-depressant. In a Japanese study, lemon essential oil in vapour form has been found to reduce stress in mice.
- Lemon oil - Researchers at Ohio State University reveals that Lemon oil aroma may enhance one's mood, and help with relaxation.
Efficacy
Some benefits that have been linked to aromatherapy, such as relaxation and clarity of mind, may arise from the placebo effect rather than from the inherent properties of the scents themselves. The consensus among most medical professionals is that while some aromas have demonstrated effects on mood and relaxation and may have related benefits for patients, there is currently insufficient scientific proof of many of the claims made for aromatherapy. Scientific research on the cause and effect of aromatherapy is limited, although in vitro testing has revealed some antibacterial and antiviral effects and a few double blind studies have been published. Essential oils have a demonstrated efficacy in dental mouthwash products.
Like many alternative therapies, few controlled, double-blind studies have been carried out—a common explanation is that there is little incentive to do so if the results of the studies are not patentable. Researchers at Sloan-Kettering have found that aromatherapy significantly reduces claustrophobia attacks for patients undergoing MRI scans; however, studies of similar rigor are far from numerous.
Skeptical literature suggests that aromatherapy is based on the anecdotal evidence of its benefits rather than proof that aromatherapy can cure diseases. Scientists and medical professionals acknowledge that aromatherapy has limited scientific support, but critics argue that the claims of most aromatherapy practitioners go beyond the data, and/or that the studies are neither adequately controlled nor peer reviewed.
Some proponents of aromatherapy believe that the claimed effect of each type of oil is not caused by the chemicals in the oil interacting with the senses, but because the oil contains a distillation of the "life force" of the plant from which it is derived that will "balance the energies" of the body and promote healing or well-being by purging negative vibrations from the body's energy field. Arguing that there is no scientific evidence that healing can be achieved, and that the claimed "energies" even exist, many skeptics reject this form of aromatherapy as pseudoscience or even quackery.
van der Watt and Janca have discovered that some of psychological disorders can be healed with the therapy through inhalation exercises, suggesting that further scientific studies, especially toxicity data, need to be conducted and collected to validate the finding
- to menopausal symptoms (inconclusive)
- to nausea (inconclusive)
Safety concerns
In addition, there are potential safety concerns.
Because essential oils are highly concentrated they can irritate the skin when used neat, that is undiluted. . Therefore, they are normally diluted with a carrier oil for topical application. Phototoxic reactions may occur with citrus peel oils such as lemon or lime. Also, many essential oils have chemical components that are sensitisers (meaning that they will after a number of uses cause reactions on the skin, and more so in the rest of the body). Some of the chemical allergies could even be caused by pesticides, if the original plants are cultivated
Two common oils, lavender and tea tree, have been implicated in causing gynaecomastia, an abnormal breast tissue growth, in prepubescent boys, although the report which cites this potential issue is based on observations of only three boys (and so is not a scientific study), and two of those boys were significantly above average in weight for their age, thus already prone to gynaecomastia.
A child hormone specialist at the University of Cambridge claimed "... these oils can mimic estrogens" and "people should be a little bit careful about using these products."
As with any bioactive substance, an essential oil that may be safe for the general public could still pose hazards for pregnant and lactating women.
While some advocate the ingestion of essential oils for therapeutic purposes, licensed aromatherapy professionals do not recommend self prescription due the highly toxic nature of some essential oil. Some very common oils like Eucalyptus are extremely toxic when taken internally. Doses as low as one teaspoon has been reported to cause clinically significant symptoms and severe poisoning can occur after ingestion of 4 to 5 ml.
A few reported cases of toxic reactions like liver damage and seizures have occurred after ingestion of sage, hyssop, thuja, and cedar. Accidental ingestion may happen when oils are not kept out of reach of children.
The temperature of the oil can occasionally be a safety issue, although only in extreme cases. In July 2009, former American Gladiator Jonathan Byrne received third-degree burns to his naval while self-administering therapy. Although Byrne used the term "aromatherapy", he did not follow any generally accepted treatment guidelines. In an attempt to "drive the fulsarten [sic] humors" from his body, Byrne poured a small quantity of hot olive oil into his navel. This resulted in severe injury and a short hospitalization.
Oils both ingested and applied to the skin can potentially have negative interaction with conventional medicine. For example, the topical use of methyl salicylate heavy oils like Sweet Birch and Wintergreen may cause hemorrhaging in users taking the anticoagulant Warfarin.
Adulterated oils may also pose problems depending on the type of substance used.Table of vaporization temperatures
See also
Notes and references
