Aromatherapy and the Brain: Part 2

Image taken by Kemal Atli

Last week, we discussed the brain mechanisms and physiological changes that are associated with aromatherapy and odor perception as a whole. Today, we will delve further into the effects – both beneficial and injurious – of specific essential oils used in the practice of aromatherapy.

Generally speaking, neophytes should avoid haphazardly inhaling or applying this oil or that oil without extensive study. Though generally considered safe, Mayo Clinic warns that essential oils “aren’t regulated by the Food and Drug Administration,” and possible side effects include “allergic reactions, skin irritation and sun sensitivity.” They also note that it is unclear if aromatherapy may exert deleterious effects in women who are nursing or pregnant, in infants and children, and in people taking certain medications. The uncertainty regarding side effects and contraindications stems from the lack of “consistency in the specific treatments used for specific illnesses among practitioners. This lack of standardization has led to poor consistency in research on the effects of aromatherapy, because anecdotal evidence alone or previous experience has driven the choice of oils, and different researchers often choose different oils when studying the same applications.” Furthermore, there is a possibility that some degree of aromatherapy’s purported effectiveness may be a result of the placebo effect. An article in Yale Scientific mentions that, “Several studies conducted at the Monell Chemical Senses Center found that subjects who were informed that an odor would improve performance achieved better results in a series of math calculations. These studies show that people’s expectations about odors have the power to affect their health and behavior. Thus, scents that are perceived as positive may actually induce their positive effects due to the placebo effect.”

Despite these various research issues, there are some potentially promising results of several aromatherapy studies. Below is a summary of three studies on specific essential oils:


 Researchers in Israel demonstrated that frankincense might exert antidepressant and anxiolytic effects in mice. The animal subjects “were willing to tarry longer in open spaces, where they generally feel vulnerable to attack, indicating a dip in anxiety… and they paddled longer before giving up and floating [when trapped in a small body of water], a behavior associated with antidepressive compounds.” The article also suggests that, “The active ingredient in frankincense lights up brain receptors that play a role in the perception of warmth on the skin and might help regulate emotion.”


 One clinical study conducted over six months “tested the fragrances of peppermint… to trigger significant loss in weight in a large group of patients who had previously been unsuccessful in weight-management programs.” The peppermint oil was remarkably successful; in fact, in some cases it was almost too successful: “some patients actually had to be dropped from the study to avoid becoming underweight.” Overall, the “average loss [among the 3,000 participants] exceeded 30 pounds.” Thus, the use of peppermint oil in aromatherapy may be a viable solution in combating obesity.

Lemon Balm

Researchers in the United Kingdom measured the effects of lemon balm oil in patients with dementia-related agitation. The oil was emulsified in a lotion and topically applied to participants’ faces twice a day. Of those that completed the trial, “Sixty percent (21/35) of the active treatment group and 14% (5/36) of the placebo-treated group experienced a 30% reduction of [clinically significant agitation].” Moreover, “Quality of life indices also improved significantly more in people receiving essential balm oil,” as measured by “percentage of time spent socially withdrawn [and] percentage of time engaged in constructive activities.”

Final Notes

The world of essential oils is vast and our knowledge of their mechanisms and possible therapeutic effects is far from complete. However, it is possible to use them as a supplement to modern medicine. France proves this notion. Here, “Aromatherapy is incorporated into mainstream medicine as an antiseptic, antiviral, antifungal and antibacterial, much more so than in the UK, USA or Canada. In fact, there are some essential oils that are regulated as prescription drugs in France, and can only be administered (or prescribed) by a doctor.” French physicians use a complex process combining aromatograms, culture samples, and targeted microbiology. With more – and more consistent – research on the subject, aromatherapy could prove to be a useful treatment for a spectrum of ailments.

-Written by Betty Vine

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