Essential oil is the umbrella name given to a variety of aromatic compounds extracted from plant material. About 90 per cent are correctly called essential oils, the product of distillation. The remainder are essences, produced by expression (squeezing) of citrus rinds, and absolutes, flower scents such as rose and jasmine, extracted by a method that includes using solvents and ends with a lower temperature alcohol distillation.
September 16, 2009 By Maggie Mann RMT Aromatherapist
Essential oil is the umbrella name given to a variety of aromatic compounds extracted from plant material. About 90 per cent are correctly called essential oils, the product of distillation. The remainder are essences, produced by expression (squeezing) of citrus rinds, and absolutes, flower scents such as rose and jasmine, extracted by a method that includes using solvents and ends with a lower temperature alcohol distillation. Steam distillation destroys their delicate scent.
Other specialty extraction methods include “CO2” and “phytols,” however both are rare and expensive and therefore not usually available to lay aromatherapists.
Essential oils are essential to the plant, but they are not an oil. Unlike oil they are not emollient (oily and smooth to the touch), and they are volatile. They evaporate readily, often leaving no stain, which cannot be said for massage oil that stains sheets.
Essential oils’ secretory cells are found in a wide variety of locations within a plant. Everywhere from the roots (ginger and vetiver), the heart wood (sandalwood), the leaves (peppermint, eucalyptus, marjoram, basil), flowers (rose, jasmine) and the seeds (coriander) produce essential oils.
One tree, the bitter orange (Citrus aurantium var. amara), produces essential oils in three places, neroli from the orange blossom, bitter orange from the rind of the fruit, and petitgrain from the leaves and twigs.
If essential oils were only found in one place in plants then it would seem reasonable that they only
perform one function for the plant, but as they are produced in so many places then we can theorize that
they perform more than one function.
Can humans utilize them for the same reasons that plants produce them? Several theories suggest that we can. For instance, most, but not all, flowers produce a scent.
We know that floral scents are used to attract pollinators, necessary for the survival of the species.
We humans have developed a multi-million dollar industry based on attracting others with scent; the perfume industry. When we wear scent we are saying, “I’m over here, come on over, I smell good.”
In aromatherapy we use scent therapeutically. If you apply a scent, either a single essential oil or a synergistic blend it can impart confidence, or lift our spirits – it can help us change our attitude. Symbolically it is a very self-loving, self-healing action.
A further theory suggests that essential oils function as the immune system of the plant, protecting it from invading organisms. Research has shown that essential oils of thyme, lemon and tea tree all help the human body to produce more T4 lymphocyte cells.
Essential oils are anti-microbial, they kill or inhibit most bacteria, some viruses and fungi when they come in direct contact with them.
We use essential oils topically as anti-septics (tea tree for cuts and scrapes) as antivirals (tea tree or lemon for plantar’s warts), and as antifungals (tea tree and myrrh for athletes foot). An interesting theory suggests that essential oils play a role as the hormones of the plant.
They help regulate the growth of the plant in response to external stimuli, such as rain or drought or to changing light conditions. They may direct whether the conditions are right for flowering, or whether the plant should conserve energy this year and try flowering next year.
Some essential oils act as a hormone precursor in humans, or closely resemble human hormones, or stimulate parts of the brain, such as the hypothalamus to produce hormones.
A final theory suggests that essential oils protect plants from encroachment by other plants. In the hot mediterranean climate that grows many of the essential oils in the lamiaceae family such as lavender and rosemary, water is scarce. Each plant needs a certain amount of “personal space” to be able to survive.
It is thought that the highly aromatic lamiaceae family creates an environment around themselves that is inhospitable to seed germination by the evaporation of essential oils, thereby reducing competition for the available water.
At first I could not see a way in which this theory could benefit humans, but then I remembered the first time I used citronella in a mosquito infested forest. The effect was instantaneous. The bugs stayed about two feet away, causing a halo effect as there were so many of them.
I am sure that there will continue to be scientific evidence to back up the many years and centuries of essential oils usage for curing illness and enhancing health.
In the next article I will explore different ways of applying essential oils therapeutically, and making
some suggestions that massage therapists can easily incorporate into their practices.
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