What is the difference between a scented candle and an aromatherapy one? Answer: About ten dollars.
Joking aside, ordinary fragrant materials supposedly become imbued with healing power when—well, when they are sold for that purpose. Aromatherapy is the pseudoscience of using aromatic substances for claimed improvements to one’s physical or mental health. However, medical evidence is lacking that aromatherapy is beneficial in preventing, treating, or curing any disease—other than by the ubiquitous placebo effect.
History
Aromatherapy has its roots (no pun intended) in the ancient herbal practices of early civilizations, including the Chinese, Egyptians, Romans, and others. Certain aromatic plants seemed to offer benefits—for example, peppermint as a tea to soothe digestive upsets, myrrh as a spice for burial wrappings, and frankincense for holy anointing (Farrer-Halls 2005, 302–303; Nickell 1998, 37–38; Wilson 2003, 17). However, herbal uses do not constitute aromatherapy.
Essentially (pun intended) the use of essential oils—volatile natural oils that impart to plants their characteristic odors—foreshadowed the practice of aromatherapy. Whereas ancients had used the oils in cosmetics, perfumes, salves, and ointments, and Hippocrates reportedly advised the use of scented massages (Essential Oils Academy 2019), aromatherapy actually developed only in the past hundred years.
It was advanced by an incident in 1910 involving a French chemist and perfumer, René Gattefossé (1881–1950). He burned his hands in a lab accident, and gas gangrene rapidly developed. However, he rinsed the burns with lavender essence, whereupon healing began the next day. In 1937, he published his classic work, Aromatherapie, coining that word (“Real Story” 2016).
It remained for essential oils to be combined in the 1960s with certain massage techniques (i.e., “intuitive” and Swedish), and this led to today’s practice of aromatherapy as a so-called healing art (Farrer-Halls 2005, 10).
Claimed Effects
Aromatherapy’s reliance on essential oils raises other issues. With characteristic insight, Harriet Hall (2013), known as “The SkepDoc,” observed that “so many of the oils are supposed to do the same things.”
Consider, for example, a small aromatherapy kit containing just seven essential oils. Four (clary sage, orange, lavender, and chamomile) promise very similar effects summed up by the word calming (e.g., “soothes, calms,” “eases anxiety,” etc.). All four are said to have “sedative” properties. The other three (peppermint, rose, and rosemary) are billed as “stimulating” or “uplifting,” etc. How does someone decide which to employ?
At the same time, aromatherapists promote specific mixtures of oils for a variety of alleged purposes: to treat everything from an itchy scalp, troubled skin, and sore muscles to the control of pathogens and management of hunger. One blend is even touted for its purported anti-aging power (Hall 2013). (See also, Susan Gould, “Essential Oils: One Weird Workshop,” Skeptical Inquirer, November/December 2018, and Lynn McCutcheon, “What’s That I Smell: The Claims of Aromatherapy,” SI, May/June 1996.)
Power of Suggestion
Countless beneficial uses for aromatherapy are claimed, and two main mechanisms are cited to explain the purported effects: (1) how aromas affect the brain’s limbic system (which deals with emotions, memories, and stimulation), and (2) direct pharmacological effects of the applied essential oils (“Aromatherapy” 2019). However, I believe we must add one more: body massage, because that is the main method (in addition to aerial diffusion, direct inhalation, baths, etc.) by which essential oils are applied. The massage itself may have a soothing, stimulating, or other effect that is equal to or greater than the effect of the chemistry of the oil or the mere fact of its application. According to Farrer-Halls (2005, 11, 121), “Massage is the best way to release physical tension.”
The use of massage therefore raises the broader issue of suggestion. The Aromatherapy Bible asserts that two drops of lavender simply rubbed into one’s temples “relieves headaches,” but is it the fragrance, the rubbing, or—as I strongly suspect—the suggestion that effects the relief? Similarly, orange merely used in “local massage and compresses” is allegedly good “for settling digestive upsets,” and clary sage applied in a bath supposedly “relaxes mind and body” and “eases pain.” Peppermint—long used, as we have seen, to relieve digestive upsets—does so even “massaged over the abdomen in a clockwise direction” (Farrer-Halls 2005, 273, 295, 302, 319). But are there any blinded comparative studies for counterclockwise massage?
Again, rose “comforts the heart in grief.” How do we know? Why, it is “associated with the heart chakra” (Farrer-Halls 2005, 259). Thus, pseudoscience is used to support other pseudoscience. Chakras are (nonexistent) “energy centers” through which allegedly flows the (nonexistent) “universal life force” called chi (Farrer-Halls 2005, 254–262; Guiley 1991, 86–88, 625; Nickell 2017, 29–22). (Incidentally, in addition to chakras, aromatherapy is also touted to work in conjunction with crystal healing, astrology, aura cleansing, and other “alternative” therapies, including, as mentioned, massage techniques [Farrer-Halls 205, 160–167, 252–253, 263–267].)
Still many other essential oils may work mostly—or entirely—by suggestion. Of the seven in the kit previously mentioned, we have looked at five; here are the other two: Rosemary is claimed to improve memory, for example, when a drop is mixed with two drops of oil of neroli (bitter orange) flowers and “dabbed on the wrists”—say before taking a test. (The neroli is supposed to calm one’s nerves; see Farrer-Halls 2005, 293–294.) Finally, Roman chamomile is said to relieve the cramps and mood swings of menstruation when used in baths, with compresses, and even as “mood perfumes”—all methods that seem indistinguishable from suggestion, i.e., the placebo effect at work.
The Evidence
Quackwatch webmaster Dr. Stephen Barrett (2001) sums up the evidence: “Pleasant odors can be enjoyable and may enhance people’s efforts to relax. However, there is no evidence that aromatherapy products provide the health benefits claimed by their proponents.”
Good medical evidence is lacking to show that aromatherapy can either cure or prevent a single disease. In 2015, Australia’s Department of Health published a review of “alternative” therapies, seeking to find whether they were suitable for health insurance coverage. Aromatherapy was one of seventeen evaluated therapies that lacked clear evidence of effectiveness. Many other reviews likewise report an absence of evidence for aromatherapy as a treatment. Large, well-designed, suitably randomized, and controlled trials are lacking. Moreover, there are studies showing that some essential oils may actually be toxic to humans (“Aromatherapy” 2019).
The conclusion that aromatherapy is simply just another New Age pseudoscience seems unlikely to change. Its theories and practices—as have frequently been pointed out—fail to pass the smell test.
References
Aromatherapy. 2019. Available online at https://en.wikipedia.org/wiki/Aromatherapy; accessed July 11, 2019.
Barrett, Stephen. 2001. Aromatherapy: Making Dollars Out of Scents. Available online at https://www.quackwatch.org/01QuackeryRelatedTopics/aroma.html; accessed July 16, 2019.
Essential Oils Academy. 2019. Available online at https://essentialoilsacademy.com/history; accessed July 11, 2019.
Farrer-Halls, Gill. 2005. The Aromatherapy Bible. New York, NY: Sterling Publishing Co.
Guiley, Rosemary. 1991. Encyclopedia of the Strange, Mystical, & Unexplained. New York, NY: Grammercy Books.
Hall, Harriet. 2013. doTERRA: Multilevel marketing of essential oils. Science-Based Medicine blog. Available online at http://sciencebasedmedicine.org/doterra-multilevel-marketing-of-essential=oils/; accessed July 11, 2019.
Nickell, Joe. 1998. Inquest on the Shroud of Turin. Amherst, NY: Prometheus Books.
———. 2017. Claims of chi: Besting a Tai Chi master. Skeptical Inquirer 41(1) (January/February).
The Real Story of René-Maurice Gattefossé. 2016. Available online at https://oilwellessentials4health.wordpresss.com/2016/02/02/the-real-story-of-maurice-gattefosse-essential-oils-during-the-past-century-part-ii; accessed July 11, 2019.
Wilson, Colleen. 2003. Heaven Scent: Miraculous Healing Oils from the Bible. Boca Raton, FL: American Media Mini Mags.