Chapter 1
THE NATURE OF AROMATHERAPY
Like herbalism, aromatherapy draws on the healing powers of the plant world, but instead of using the whole or part of a plant, it employs only its essential oil. This potent, aromatic substance is housed in tiny glands on the outside or deep inside the roots, wood, leaves, flowers, or fruit of a plant. It is a dynamic, concentrated representation of the healing properties of the plant, and is believed by some to contain its life force. Hence care must be taken to extract the oil in its pure state.
In aromatherapy, inhalation, application, and baths are the principal methods used to encourage essential oils to enter the body. Essential oils are highly volatile, evaporating readily on exposure to air, and when inhaled, may enter the body via the olfactory system. When diluted and applied externally, essential oil molecules may permeate the skin. Bath treatments enable you to both inhale and absorb the oils. For detailed information on the main routes of entry into the body, see pages 16 to 17.
Once within your system, essential oils will work to re-establish harmony and revitalize those systems or organs where there is a malfunction or lack of balance. Their effects are many and varied (pages 16 and 93), but they are noted in particular for their antiseptic properties and their ability to restore balance to both body and mind.
A variety of factors help to determine the effectiveness of an aromatherapy treatment: the quality of the essential oils, their appropriateness for a particular individual or a specific ailment, the methods by which they are applied (pages 21 to 32), and, in the case of a professional treatment, the extent and quality of interaction between the therapist and the patient (page 33). When, for example, specialized aromatherapy massage is combined with the holistic selection of oils by a trained therapist, the effects can be truly exceptional. With self-help aromatherapy, you will be using oils recommended for a particular ailment or preventative treatment, but it should not take you long to discover which of them work best for you as an individual, particularly since simply liking the aroma of an oil may indicate that it will help you.
Producing Quality Essential Oils
To work therapeutically, essential oils need to be of the highest quality: pure, unadulterated, and, preferably, harvested from organically grown plants cultivated in optimum conditions.
When aromatic plants are produced for the perfume and food industries, the use of pesticides and fertilizers is accepted, since it gives greater and more uniform yields. For aromatherapy, natural, or organic, growing methods are preferred, since agrochemicals may come through in the extraction process. The altitude and soil in which the plants are grown are also important in determining the quality of the oil. Lavender raised at a high altitude on stony, dry soil yields oil of a higher therapeutic standard than that grown in rich, damp conditions on low ground. The time chosen for harvesting is significant, since it affects not only the concentration of essential oil in the plant but also its chemical composition.
The essential oil of a plant may also be affected by chemotyping, a process whereby cuttings are raised in such a way that they produce more of a desired chemical constituent. The genus of Thyme, for example, has one chemotype (for use by professional aromatherapists only) that contains a high level of carvacrol, a powerful antiseptic. By contrast, linalol, geraniol, and thujanol chemotypes of Thyme have much gentler properties. All, however, are sold under the same latin name and, unless details are given on the label, it is best not to buy or use Thyme essential oil, since the carvacrol chemotype is the one most commonly available.
To extract essential oils in their pure state, different methods are used depending on where the essential oil is situated. With plants from the Labiatae family, such as Lavender and Peppermint, the essential oil glands are easily accessible, being situated on the outside of the leaves. This makes them suitable for distillation, a process in which the freshly picked or dried plant material is packed tightly into a still and steam sent through it. The heat bursts open the glands and the oil evaporates, mixing with the steam. A cooling process returns the vapours to their liquid state and the essential oil separates from the water. In the Myrtaceae family, which includes both Eucalyptus and Tea Tree, the glands are less accessible and may need bruising prior to distillation.
Citrus fruits yield their oils through hand or machine expression, which involves squeezing or scraping the rind. Where essential oil is contained in the naturally secreted resin of a plant, a solvent may be used in the extraction process. The exuded resin is dissolved in warm alcohol and filtered. The alcohol is then removed at a low temperature, leaving the resinoid: the essential oil plus a small proportion of the chemicals used. Absolutes of Rose and Orange Blossom are produced by a similar process; they have different chemical compositions and aromas to the pure, distilled oils of Rose Otto and Neroli (Orange Blossom).
Aromatherapy users make up a negligible part of the worldwide market for essential oils. Perfume and food manufacturers, together with the pharmaceutical industry, are the main consumers. Sadly, neither of the first two is concerned primarily with purity, but rather require the oils they buy to conform to a set standard. Without adulteration, this is impossible to achieve, since essential oils are like wine - they have good and bad years, and their aromas and flavours vary accordingly. When an oil fails to meet a customer's requirement, steps may be taken to bring it up to the required standard by adding: a poorer quality oil, a single aromatic constituent (natural or synthesized), or alcohol. As a result, sources of pure essential oils have diminished, and it is doubtful supply will meet the increase in demand predicted for the year 2000.
Oils and their Chemistry
Essential oils have complex molecular structures and may contain up to several hundred different natural chemicals. Alcohols, esters, ketones, phenols, and aldehydes are those that feature prominently and which have been most closely studied with regard to their therapeutic potential. In general, essential oils high in alcohols and esters have gentle healing properties and are safe for home use. Ketones, phenols, and aldehydes are more powerful chemicals that are also active therapeutically. Oils that contain high concentrations of these are rarely used in aromatherapy (List B, page 5), since they can have adverse effects if employed incorrectly; you should not include them in self-help treatments. A professional aromatherapist, however, may prescribe them in very small doses as a means of providing speedy relief for a specific complaint.
Many of the other chemicals present in an essential oil (including the minor and, as yet, nameless ones) are thought to play a vital role in preventing side effects. Evidence for this has come from the current practice of isolating the therapeutic elements of essential oils and incorporating them in tablets and other forms of medication. The aldehyde, citral, for example, is present in lemon oil and has many beneficial effects on the body. When isolated, however, it is a very toxic substance that can cause severe skin irritation. The indication that these chemicals may contribute to the total action, or synergy, of an oil is one of the reasons why aromatherapists believe that synthetically produced equivalents cannot possibly be as effective, and that they may even be potentially hazardous.
Copyright © 1991 Gaia Books Ltd. London
