By Marguerite Fly Bevis, RN, BSN
This article, part 1 of a 2 part article on essential oils, describes their basic properties and why they are used. Part 2 will describe how to use them.
Essential oils, the quintessential essence of medicinal plants, have been used by man for therapeutic purposes for thousands of years. They are mentioned in the Bible at least 600 times. Thirty-three different oils are mentioned. Essential oils are the original medicine upon which modern medicine is based. Birch and wintergreen contain salicylic acid, the same component in aspirin but essential oils are easier on the body and present fewer, if any, side effects, whereas modern medicines can have many, some of which can be more dangerous than the illness itself. Plant-based medicines are gentle, working naturally with the body’s self-defense mechanisms.
Aromatherapy is so much more than a spa treatment. Research has shown that people who consistently use essential oils have fewer illnesses and when they do get ill, they recover 70% faster than those not using them. The oils contain molecules that are fat-soluble and tiny enough to cross the skin barrier and into the blood-stream. Some are known to cross the brain barrier! The implications for people suffering from neurological disorders are enormous.
Realizing that essential oils are plant-based medicine, we gain new respect and admiration for the myriad therapeutic benefits of each oil. We also realize that they are complicated and must be treated with the same respect as modern medicine when it comes to dosage and application. Understanding the chemistry helps us understand the oil. Each oil is made up of several different chemical compounds, hydrocarbon molecules, and are further classified into their specific chemical families, also called functional groups. Functional groups are specific groups of atoms within molecules responsible for the characteristic reactions of each chemical. Members of each functional group exhibit similar chemical reactions.
Monoterpene Hydrocarbons (Monoterpenes)
- Are found in almost all essential oils, considered the “top note,” or first thing you smell
- React to air and heat, short shelf life
- Are anti-inflammatory, antiseptic, anti-viral and antibacterial, as well as analgesic or stimulating
- Stimulate mucous membranes, useful as decongestant
- Are therapeutic for respiratory and muscular system
- Help support normal information in the DNA of cells
- Deeply penetrate, disinfect, and help with respiratory problems
- Comprise a widely varied list of benefits
Piney oils (pinene) and citrus oils (limonene) are well-known monoterpenes.
- Comprise the largest group of terpenes and present in most essential oils. Good choices for cooling inflammation and soothing pain.
- Have a shelf life of six to eight years.
- Include heavier oils (middle and base notes)
- Can be calming and energizing
- Are soothing and calming to irritated skin and tissue
- Have the ability to pass through the blood-brain barrier and enter the brain tissue
Monoterpene Alcohols (Monoterpenols)
- Have antiseptic, anti-viral and anti-fungal properties
- Relieve stress and promote relaxation
- Promote uplifting energizing effect
Examples of monoterpenols are linalool in lavendar, citronellol in rose and terpeneol in geranium, juniper and tea tree oils
Sequiterpene Alcohols (Sesquiterpenols)
- Are not as common as monoterpenols
- Act as liver and glandular stimulant
- Have anti-allergen and anti-inflammatory properties
- Are found in sandalwood (alpha-santalol), ginger, rose, patchouli, vetiver, ylang ylang and cedarwood
- Work with phenols to clean the receptor sites (proteins located on the surface of each cell)
- Are considered to be the base notes in aroma (after-taste)
- Generally have grounding, inflammation cooling properties
- Have shelf life of six years or longer
- Are anti-septic, anti-bacterial, anti-viral and disinfectants
- Have anesthetic and analgesic properties
- Antioxidant – protect against cellular damage
- Have stimulating therapeutic properties
- Should be diluted and used for only short periods of time (maximum 10 days)
- Can lead to toxicity if used over long periods of time
- Are classified as skin and mucous membrances and can cause severe skin reactions
Examples of phenols are cinnamon, clove, thyme, oregano, rosemary, Holy basil
- Are anti-fungal, anti-inflammatory, disinfectant and sedating, yet uplifting
- Comprise the citrus-like fragrance in melissa, lemongrass and citronella oils
- Are also found in cumin, eucalyptus, cassia
- Are calming and sedating.
- Stimulate cell regeneration, promote new tissue growth, liquefy mucus
Examples of ketones include eucalyptus and rosemary; another example is turmerone, found only in turmeric which has been found to balance blood sugar levels and promote normal neural stem cell growth. Use with care during pregnancy, consult with physician before use.
- Are formed from alcohols and acids
- Are highly fragrant and tend to be fruity
- Are sedating and anti-spasmodic
- Some have anti-fungal and anti-microbial properties
The compound linalyl acetate is found in lavendar, bergamot,clary sage, birch, wintergreen, cardamon, ylang ylang, helichrysum, jasmine, and Roman chamomile.
- Are derived from other compounds such as alcohols, terpenes or ketones that have been oxidized
- Are expectorants
- Are mildly stimulating
- Are found in eucalyptus, rosemary, peppermint, cardamon and thyme
Black Pepper (Piper nigrum)
There is evidence that pepper has been since at least 2000 B.C. in India. There are references to black pepper in Greek and Roman text. Invigorating when mixed with other oils and inhaled, it is a warm and spicy oil used for sore muscles and joints; it also shows potential for addressing pain and mood health problems. It helps support digestion and circulation, helps reduce food cravings and has been used to help stop smoking. Because it increases sweating and urination, it helps to naturally detoxify bodily toxins and excess water. Its key compounds are caryophyllene (a sesquiterpene) which contributes the spiciness and has inflammation-cooling abilities, D-limonene, alpha-pinene, and beta-pinene (all monoterpenes). Although it is used topically with a carrier oil on affected muscles or joints, it can be taken internally, only one or two drops added to a smoothie, soup or other savory dishes. It can be an irritant if taken in high doses.
Ginger (Cymbopogon nardus)
In the 14th Century, ginger was as valuable in trade as a live animal. It was used widely as a tonic for various ailments. The main compounds in ginger are sesquiterpenes, monoterpenes and small amounts of oxides. Ginger is very popular in Chinese medicine because it is a warming oil, in contrast to cooling oils containing menthol. One component, gingerol, has powerful anti-inflammation properties and is also effective for nausea and digestive disorders, joint and chronic pain as well as respiratory problems. It is sometimes referred to as the “oil of empowerment” because it is known to promote feelings of self-confidence and courage. Well known as an effective insect repellent, it should be used diluted in a carrier oil.
Coriander (Coriandrum sativum)
Coriander oil, steam-distilled from the seeds of the same plant used to make cilantro oil, is excellent for skin irritations, may be used to stimulate appetite and for digestive problems. A study done in 2014 found that coriander was effective against fungal infection of the oral cavity. It also displays antimicrobial activity against all bacteria tested. Coriander pairs well with cilantro oil but should be diluted with a carrier oil before applying topically.