Aromatherapy | Health Articles | The meaning of Aromatherapy and the chemistry of Essential Oils

The meaning of Aromatherapy

The term aromatherapy has been in existence for a relatively short period of time in history. However, principles and practices lying behind the concept can be traced back to some of the ancient civilizations of mankind. In researching this question we are left with a sense that people view aromatherapy from a variety of perspectives, including:

A way of pampering yourself, a means to a very relaxing massage, a metaphysical experience induced by the aromatic properties of an essential oil, a pleasant way of maintaining health and vitality, an excursion into the unknown and unproven that shouldn't be undertaken, a considered alternative health treatment that focuses on the total or holistic health of an individual. The Collins English Dictionary Millennium Edition, 2000 defines aromatherapy as:

"The use of fragrant essential oils extracted from plants as a treatment in alternative medicine to relieve tension and cure certain minor ailments."

Some authors define aromatherapy in the following ways:

"Aromatherapy is the use of therapeutic oils extracted from natural plant matter in order to encourage good health, equilibrium, and well-being." (Clare Walters)

"Aromatherapy is a multifaceted healing art which uses the essential oils of aromatic plants and trees to promote health of body and serenity of mind" (Chrissie Wildwood)

Aromatherapy "could be seen as part of the larger field of herbal medicine, since the essential oil is only one of many ways in which a plant can be prepared as a remedy." p. 24 Julia Lawless;

From this variety of descriptions, it seems that there is no universal singular definition of aromatherapy. The lack of a universally accepted definition for a particular practice is not an unusual occurrence in the field of health. For example, the concept of medicine is also difficult to define, because there are so many facets to consider. However, a discernible common feature in all definitions is that aromatherapy is an activity that uses essential oils for a therapeutic purpose.

The roots of this health practice are ancient. Despite the trend in the last 150 years of both the medical fraternity and public health systems to focus on healthcare pharmaceutical products, it is evident from the growth in interest in alternative therapies that the principles on which plant therapies are based continue to be valid.

The word aromatherapy came from the unplanned use of lavender essential oil following an accident in a perfumery laboratory. Ren Maurice Gattefoss coined the term aromatherapie in 1928 to imply the therapeutic use of aromatic substances (essential oils) that he discovered following his use of lavender essential oil to cool a severe burn he suffered in that accident.

Essential oils

As noted above, the concept of aromatherapy involves the use of oils extracted from certain plants, known as essential oils. These oils are extracted from various parts of aromatic plants and trees, using a variety of methods namely steam distillation, cold expression, and solvent extraction.
When looking at oils that are extracted using solvents, the author recommends to look for oils that have been extracted using liquid carbon dioxide as the solvent agent. This gives a better quality oil, as the process leaves no solvent residue. However, the use of liquid carbon dioxide does make the extraction process slightly more expensive but the consumer knows that the slightly higher price is more than compensated by the quality of the oil. Consumers wanting a better quality rose oil are well advised to choose one that is extracted using liquid carbon dioxide (CO2),

What are essential oils?

Essential oils are the liquid extracts from aromatic plants trees and grasses. The term essential oil is derived from the word quintessence, meaning an "extract of a substance containing its principle in its most concentrated form". Essential oils are highly volatile and evaporate quickly if left in the open air. When left in the open air, the oils create an aromatic scent, as reflected in the name aromatherapie.

Essential oils may be found in different parts of the aromatic plants, for example, in petals (rose oil), leaves (eucalyptus oils), grass roots (vetiver oil), and fruit rind (lemon oil). The essential oil may also be found in different parts of a plant as for example the orange tree from which neroli oil is obtained from the flowers, petitgrain oil from the leaves and orange oil from the fruit rind. The essential oils seem to have an important function for plants, ranging from attracting pollinating insects to being a protective mechanism against insects, animals and fungi.

The plants accumulate these essences in their oil glands. The more oil glands a plant has, the greater the quantity of the essential oil that can be extracted. Clearly this impacts on the cost of manufacturing, as those plants with the lower count of oil glands will tend to require greater quantities of the plant material to produce the essential oil. For example, it takes approximately 220 pounds of rose petals to derive aboutgallon of rose oil whereas the same quantity of lavender will produce almost ½ gallon of lavender oil.

Chemistry of essential oils

Every essential oil has a unique chemical composition, determined by the plant variety and the geographical location at which the plants are grown. An example of this is eucalyptus oil, of which there are several varieties used in aromatherapy.

It is the chemistry of the oil that determines the fragrance, the color, the degree of volatility, and the ways in which that oil interacts with the human body. The chemistry of essential oils typically includes a number of differing organic compounds, such as terpenes, alcohols, aldehydes and esters. It is these chemical combinations that determine the fragrance, the color, the degree of volatility, and the therapeutic properties of the essential oil.

Because of the variety of compounds that exist in a single essential oil, it is possible for it to have multiple properties. For example, some research into manuka tree and its essential oil highlights a number of properties, anti-allergenic, anti-bacterial, anti-fungal, anti-inflammatory, anti-histamine, anti-microbial, deodorant, skin care, and tissue restoration properties. .

However, essential oils do not contain the complete chemistry that is found in the source plant. This occurs mainly because of the extraction processes that are used. As a result of the distillation process, essential oils lack water-soluble constituents of the plant material, such as tannin and sugars. The heat of distillation may also cause change to the natural chemical composition. In addition, from the time of harvest, the nature of the chemical constituents of plant materials alters due to the natural decay process. The essential oils extracted from delicate flowers through the use of organic solvents also tend to have a residue from the solvents. Typically this method is used for the oils from flower petals, such as rose and ylang ylang.

Despite the use of the biologically active compounds in plants in modern pharmaceuticals, there is still a lot to learn about the pharmacology (the therapeutic properties of the chemicals) of aromatic plants. Medical and scientific research have identified therapeutic effects of many plants, but the range of research relative to the diversity of plant species remains relatively scarce.

How essential oils are believed to work

The most common therapeutic methods of use for essential oils involves the oils entering the body's systems through the skin or via inhalation. Because of their small molecular structure, especially their fat-soluble nature, essential oils can penetrate the skin more freely than other types of plant oils, for example, vegetable oils.

The aromatic nature of essential oils is an important characteristic that the ancient art of perfumery is based on. It is clear that the sense of smell is important as a defensive mechanism, for example in the avoidance of repulsive odors. It is only in relatively recent history that scientific and medical research has identified that some infectious microorganisms were associated with putrid odors. So it should come as no surprise that aromatherapists utilize the sense of smell as part of their therapeutic art.

Aromatherapists believe that the active chemicals in an essential oil that are detected by the sense of smell are sensed by the limbic system, part of the body's control system, and this in turn impacts on the emotions. In this way, aromatherapists consider that essential oils may have both a physiological effect and a psychological effect.

Essential oil safety

What is most important is that the benefits and risks are clearly spelled out. There have been some exaggerated claims over some natural therapies. Governments are rightly concerned that their citizens are not put to unnecessary risks with any health therapy, as health is such a precious commodity in people's lives.

What is important is that the public be given better information about the potential for a person to benefit from the different alternative therapies from national organizations. Because of my personal health challenges I have come to respect alternative health therapies, and as the use of essential oils, and in particular, their pharmacologically active compounds, is developing, so to is the growth in interest from medical researchers.

References:
Lawless, J., 1995. The Illustrated Encyclopedia of Essential Oils. London: Harper Collins Publishers Limited.
Schiller, C., and Schiller, D., 1996. Aromatherapy Oils: A complete guide. New York: Sterling Publishing Co, Inc
Walters, C., 1998. Aromatherapy: An illustrated guide. Boston: Element Books Inc.
Worwood, V.A., 1991. The Fragrant Pharmacy: A complete guide to Aromatherapy and Essential Oils. London: Random House Group Ltd.
World Health Organization fact sheet. Complementary health fact sheet