Essential oils are all the rage at the moment, in part because of multilevel marketing—but while I’m not a huge fan of MLM in general, that doesn’t mean that essential oils themselves don’t have their place in the pharmacopeia of natural medicines.
But first, a few definitions.
Essential Oils vs Herbs
Herbs can involve parts of the whole plant, including the flower, leaf, stem, or root. Which part is used depends upon the herb in question, and which constituents you’re trying to extract. Some cannot be taken orally, but most can, and are. The most common medicinal preparations are capsules or tinctures, but they can also be extracted into body oils, salves, teas, and more. For this reason, herbs are more diverse (and safer) than essential oils.
Essential oils are produced by heating the plant by steam distillation, until the oil of the plant is extracted. The only part of the plant involved is its oil, and the rest gets discarded. Think of this a little like juicing (by analogy): you extract the juice, and discard the rest of the fruit or vegetable, so it therefore takes (for instance) an entire bunch of celery to make a single 16 oz cup of juice. Extracting essential oils likewise requires enormous amounts of the plant to produce a very small amount of oil—and therefore essential oils are super concentrated in terms of their medicinal effect. For this reason, with few exceptions, they should generally not be taken internally. Even most topical applications require dilution in carrier oils to avoid skin irritation.
Effects of Common Essential Oils
Here are a few studies to back up claims of some of the best known essential oils.
- Tea tree oil has broad-spectrum antimicrobial properties: it is antifungal, antibacterial, and antiviral. But it should not be taken internally.
- Eucalyptus is one of my favorites this time of year for diffusing, as it is not only antiviral, antibacterial, and antifungal, but it is also a decongestant and expectorant (helps clear phlegm). Also not for internal use, and contraindicated in pregnancy and for young children under 6.
- Peppermint is one of the few oils that can be taken internally. It is often recommended for flatulence, nausea, and indigestion. Also contraindicated in pregnancy and for children under 6, as well as in those with epilepsy.
- Oregano is another essential oil that can be taken internally, when diluted. It is antibacterial and antiviral. Also contraindicated in pregnancy.
- Thyme essential oil can sort of be used internally, to the extent that toothpaste can: you shouldn’t swallow either, but as long as you spit them out, they can both help with dental health. You can also use it in a gargle, still provided you don’t ingest it. Also contraindicated in pregnancy.
- While we’re on the dental topic, clove essential oil is great for toothaches, and can be applied directly to the tooth a drop at a time, applied to the finger or a Q-tip. It also should not otherwise be taken internally. It’s also contraindicated in pregnancy, for children under 6, and in cancer.
Essential Oils and Neurochemistry
Essential oils are different from other types of oils because they’re volatile: that is, they’ll evaporate over time. All fragrance requires volatile chemicals in order to aerosolize such that we can smell them, and this is why essential oils are primarily known for their strong smells.
But there’s a good reason why a certain fragrance can transport you back to your childhood, or your first love, instantly putting you in a good mood. The blood-brain barrier that so carefully protects your brain from influences on the outside has a chink in its armor: the olfactory receptors in the nose. Smells bypass the blood-brain barrier and can affect the brain directly.
This is probably why many essential oils are especially known for their effect on brain chemistry, particularly when diffused. Essential oil claims range from sedative to calming to mood-lifting to improving alertness, depending upon the oil. And, it turns out, at least some of those claims are substantiated. Lavender is probably best known of the essential oils for this purpose, and it has been shown to have antidepressant, anxiolytic and sedative effects.
Essential oils are a fad, for sure, but they do have some great medicinal characteristics—provided they are used correctly.