Using Essential Oils: Definition, Chemotypes, Physiological Effects, Application and Safety
Note: The modern use of essential oils and the mass marketing of essential oils, with little to no clinical or traditional knowledge, has led to dangerous situations in which individuals and pets have been harmed or misled through false marketing claims and practices. There is a definite need to have more educated discussion
with reference to traditional use and clinical studies.
What is an essential oil? Essential oils are created and stored in specialized plant structures such as secretory cells, glandular hairs, and oil or resin ducts, and they are always segregated from other plant tissues within these areas. The secretory cells that produce the volatile oils trap the photo-electromagnetic energy of the sun and, with the help of glucose, convert it to biochemical energy in the form of aromatic molecules. (Mindy Green, Aromatherapy: A Complete Guide to the Healing Art). These oils are found in the peels, resins, gums, leaves, barks, roots, grasses, rhizomes and seeds. Plants produce these oils to attract insects for pollination, protect against predators, are anti-bacterial, and maintain the metabolic processes.
The oils in a plant, nothing added and nothing subtracted, are the essential oils. It is extracted normally through distillation. Cold press is a second method used on citrus fruits. The peel, which contains the oils and some juice, water and fruit particles, is pressed and the oil is then separated out. In some cases a chemical extraction is needed due to the low percentage of oil in a particular plant or if the structure is too delicate to withstand other methods of extraction. Chemical solvents used in this method are petroleum, ether, hexane, toluene, butane, methane, propane and even more carcinogenic materials such as benzene and acetone. This method usually applies to rose and jasmine. CO2 or supercritical carbon dioxide extraction is a new method now more widely used and is effective for plants that normally need solvent extraction. This type does not leave any chemical residue since only CO2 is used under high pressure and low heat in a closed chamber.
When distillation is used the plant oil is removed by boiling the plant matter, condensing and separating the steam produced in two different tubes. One tube will contain the water and one tube will contain the oil from the plant, unaltered. When a chemical extraction is needed the solvents are removed afterwards to leave behind only the oil from the plant. It is advised that absolutes are not used internally unless it has been verified that all chemical solvents have been removed or that CO2 extraction was used. Whatever methodology, the resulting oil should have the same chemical composition as before extraction thus "essential" because it is what is essential to the life of the plant. It is a component needed for the plant to thrive. This simple understanding also gives a parallel illustration of how this oil is possibly an essential oil for our own health.
Tomorrow I will discuss the chemotypes for a broader understanding of essential oils in biological model.
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