It seems that the prevalence and use of essential oils (EO) for curative or therapeutic purposes is becoming more widespread, or at least it's becoming more aware to me. Naturally, my first reaction to people putting drops of lemon rind oil under their tongues for healing is to laugh and lump this practice in with other questionable ones constituting alternative medicine. However, I recently noticed that my own personal sanctum, Barnes & Noble, has begun stocking EO and diffusers for relaxation and therapy, so I've decided it's time to take a closer look.
EOs refer to a class of small, hydrophobic compounds usually comprised of carbon, oxygen, and hydrogen produced by plants in their seeds, leaves, bark, and small secretory hairs called glandular trichomes. (On a side note: for any cannabis aficionados, glandular trichomes are also the structures that secrete THC in marijuana buds.) According to many EO vendors, oils must be extracted by physical means only such as steam distillation—basically no chemical solvents allowed—in order to be considered therapeutic grade.
The term 'therapeutic grade,' as advertised on natural product websites, begs the question, “Who is grading these products?” The answer is not anybody I would trust. There is no federal regulatory agency that evaluates the quality or efficacy of any essential oil products. I suspect 'therapeutic grade' is simply a marketing tool to entice customers. Another unregulated and unstandardized term is 'natural.' It has generally come to mean minimally processed and without chemical additives, but when a product is labeled 'natural,' that actually has no legal meaning the way 'organic' does, for example. And that goes for everything, not just essential oils.
It makes sense that EOs must be extracted without chemical solvents because the added chemicals would adulterate the 'naturalness' of the product, right? Well, no. As long as the chemical structure of the oils is unaltered, they are physically, chemically, and perhaps medicinally equivalent. This consideration may have you wondering what the chemical structures of EOs look like, but again we run into a problem of chemistry; the EO from a single plant source contains many different compounds.
Take my favorite oil for example–lavender. Though it is marketed as lavender essential oil, maybe with the plant’s Latin name (Lavandula angustifolia) to attempt scientific legitimacy, the oil is really a mixture of compounds such as linalool, linalyl acetate, eucalyptol, camphor, borneol, and many others. This makes it incredibly difficult to study the effects of these oils because, if you discover an effect, you cannot know which of the dozens of compounds is responsible for it. When you take a drug prescribed by your doctor, it contains at most a few active ingredients whose concentrations are known and written on the bottle. Because there is no regulator of the EOs on the market, you can’t actually know what you’re buying, and when it costs $30 a teaspoon, I’d like to know what I’m getting.
No regulation may sound dangerous. Could you imagine if prescription drugs were unregulated? But EOs are probably safe. The lethal dose of orally ingested EOs is extremely high, so the most severe adverse reactions are usually rashes if applied to the skin or headaches if inhaled via diffuser. However, an article in the prestigious New England Journal of Medicine reports that lavender and tea tree oil can induce gynecomastia (abnormal breast growth) in prepubescent boys, though this result has been challenged. Pregnant women are also advised to abstain from EO use. Beyond safety, we should ask are these compounds effective biologically?
Here, anecdotal accounts from users, limited evidence from research, and relegation as pseudoscience by the conventional medicine clash. A leading vendor of EOs, Young Living, advertises several uses from improving physical health from cleaning your home to creating spiritual awareness. I won’t tackle that last one here, but as far as cleaning products go, this actually makes sense. In the research that has been conducted , the only consistent finding is that they do in fact have some antimicrobial properties. However, I find it hard to justify spending so much money on disinfectant when other, cheaper compounds such as alcohol suffice.
There has been some research done on the medicinal properties of EOs, but this research is in its very early stages, and if we’re realistic, it probably won’t advance much beyond where it is. Short of doing a full literature review on this subject, I perused a few papers exploring the effects of EOs on diabetes, obesity, and a few other diseases, and found some the results laughable. The quality of the research that has gone into EOs as medicine is far below what is done for more conventional potential drug therapies.
To wrap up, I’ll say that essential oils smell good, but beyond that, their useful applications may be limited. Natural doesn’t always mean better. In fact, it doesn’t really mean anything, and if you’re going to purchase EOs, buyer beware that you really don’t know what you’re getting.