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By Erin Oberlander, Certified Holistic Aromatherapist

By now you have probably heard mention of essential oils even if you have not yet experienced them. However, with the rise in multi-level marketing of essential oils along with the increase in popularity of natural grocers and health food stores, perhaps you also have experienced an essential oil or two.

But what are essential oils? Do you question the scientific validity of the claims being made about these substances? Do you wish you had better information about how to use these sweet-smelling substances?

It is surprising to note that only a very small percentage of plants on Earth produce essential oils. Scientists believe that it is the oldest plants, from an evolutionary standpoint, that have developed the ability to produce secondary metabolites — substances that are not necessary for the plant to exist, but which make the survivability of that plant stronger. Essential oils are one of the secondary metabolites of these plants.

Essential oils are often produced when the plant is under stress in the form of extreme temperatures or from competition from a pest. The plant produces extra chemical compounds, such as monoterpenes, sesquiterpenes, alcohols, and esters to enhance its own protection. In other words, the essential oils are the immune system of the plant. These aromatic substances have the ability to fight off insects, viruses, bacteria, and fungus and to prevent other plants from growing in the same space.

Essential oils have another function: attraction. Just as humans are drawn to the scent of a beautiful flower, so too are pollinators. Therefore, it can also be understood that the essential oils have a sexual function to help the plant reproduce by attracting bees, wasps, and other insects.

Humans are not structured the same as plants, but we do have some similarities. A plant has xylem; humans have blood. The plant has skin or bark to protect itself, much like humans have skin. The plant has sexual organs, as do we. Because of these similarities, it may be surmised that it is at least possible that essential oils will function in similar capacities in our bodies — to enhance our immunity and to improve sexual functions.

Distillation and Expression

Aromatic substances such as incense and herbal infusions have been used almost since the beginning of human history. Modern essential oils, however, were not possible to extract from the plant until the invention of the alembic still by alchemists, starting around 800 A.D. Plant material is placed in the body of a distiller vessel and heated. Steam rises and then condenses to form the two outputs of the distillation process: essential oils (the chemical compounds of the plant’s immune system in extreme concentration) and the hydrosol, which contains a small amount of suspended essential oil along with water and some of the herbaceous elements of the plant.

The exception to this process is citrus essential oils, which are produced by expression — a compression and maceration of the peels of the citrus fruits until the essential oil is drawn out and collected. These two processes — distillation and expression — are the only two ways that true essential oil can be obtained from plant material.

Olfaction — How Does Our Sense of Smell Work?

With the understanding that essential oils MAY work in the human body in similar ways to plants, the discussion must now move to HOW they may work. To do this, olfaction must be understood. Olfaction is another word for our sense of smell. In the nose is found the olfactory bulb — a dense cluster of nerve cells which are directly exposed to the air — the only nerves in the body that have total exposure to the outside without protection. Why might this be? Scientists believe that the sense of smell was one of our first senses to develop, and they also believe that the sense of smell developed as a protective function. For instance, when the body smells forest fire, the brain can then decide if it is time to run.

The olfactory bulb is located just millimeters from our limbic system, the emotional center of the brain. The limbic center directs the fight or flight response, impacts mood, influences the entire endocrine system, and in so doing, has an influence on every cell in the body. When scent molecules are inhaled into the nose, the molecules are plugged into receptors on the olfactory nerves. These nerves take the information from the scent molecules directly, and quickly, to the limbic center in the brain. The brain then decides how the body needs to react to that scent. This is why certain essential oils tend to have a calming effect while others have a stimulating effect. It is all based on the information provided to the brain by that smell and how the brain decides to interpret that smell for the body. Therefore what essential oils are used for is to enhance the function of the entire body.

Essential Oil Purity and Potency — The Cost Issue

When someone is first learning how to make homemade soap, fragrancing the soap naturally but cost-effectively is often a primary concern. Essential oils are available in a wide range of qualities and potencies, often (but not always) reflected in the cost of the essential oil. Many of the terms used to describe the quality of essential oils are marketing terms invented by companies seeking to sell those oils. It can be confusing to choose the right oil.

When it comes to therapeutic use, it is worth it to invest more in your essential oil and to research the sustainability and purity factors of that essential oil. Many companies dilute their essential oils with carrier oil to make them more cost-effective. These would not be the type one would want to choose for therapeutic use.

However, when it comes to the best essential oils for soap making, this may be an area where therapeutic benefit will be outweighed by scent and affordability because the length of time the essential oil will be present on the skin in soap will be extremely nominal. A cheap essential oil may be called for when it comes to soapmaking techniques while still achieving a beautiful scent that does not come from synthetic or petroleum-based fragrances.

What are essential oils used for in your life? Let us know in the comments below!