I’m a big fan of aromatherapy. I have a diffuser and use a number of different essential oil blends, and I’m perfectly happy if they’re just a pleasant placebo. Essential oils smell nice and they’re a great way to practice self-care.
But do they live up to the assorted health claims that are made about them?
Essential oils are made up of volatile compounds with the characteristic fragrance of the associated plant. They have been used for thousands of years for a variety of purposes.
The two primary modes of using aromatherapy are topically on the skin, including aromatherapy massage or inhaled, such as with a diffuser.
A number of systematic reviews have been performed evaluating the existing research literature base on aromatherapy. However, these reviews identified significant methodological flaws in the studies that were considered.
Study methodology matters because it affects the validity of the results obtained and whether those results are generalizable to other contexts. There’s no fundamental reason why well-designed studies can’t be conducted on alternative health treatments, although the size would likely be limited based on research funding.
A basic part of establishing whether or not a treatment is effective or not is to have a control group for comparison. Without some sort of control, positive results may not mean all that much. If a study looked at 10 patients in hospital who were given aromatherapy massage, and they reported decreased pain afterwards. It could be having the practitioner devote time to them, the massage, the oil massage in particular, the essential oil, the pleasant smell, a sense of obligation to report a beneficial effect, or any number of other factors.
Let’s consider a study by Hicks described in a paper by Perry and Perry. A mental health day hospital ward was identified on which a majority and staff and patients believed that aromatherapy was helpful. So they decided to do a study, and lo and behold, the patients’ diaries and the aromatherapists’ notes indicated that it was a resounding success. Of course, the study makes no mention of which essential oils are actually used, but that’s just a minor detail, isn’t it?
Sometimes a whole lot of words are used to disguise a whole lot of nothing, such as this excerpt from the abstract of a paper in the Asian Pacific Journal of Tropical Biomedicine:
“Once the oils are in the system, they remodulate themselves and work in a friendly manner at the site of malfunction or at the affected area. This type of therapy utilizes various permutation and combinations to get relief from numerous ailments like depression, indigestion, headache, insomnia, muscular pain, respiratory problems, skin ailments, swollen joints, urine associated complications etc. The essential oils are found to be more beneficial when other aspects of life and diet are given due consideration.”
A systematic review by Lee and colleagues noted that aromatherapy is the most often used complementary and alternative medicine intervention for anxiety worldwide. They concluded that while there were some positive indications that aromatherapy may be helpful for anxiety, the existing research is not conclusive.
Looking at a few specific essential oils, tea tree oil is known to have antimicrobial properties. There have been some positive findings, although nothing conclusive, with peppermint oil for tension headaches, fennel oil for painful menstrual periods, and lavender for sleep.
While the evidence just isn’t there to support aromatherapy as a science, it can be a fabulous self-care strategy, and there’s nothing wrong with that. If there’s some placebo effect thrown in there, that’s good too. But relying on it as a primary form of treatment is probably not the best idea.
- Ali, B., et al. (2015). Essential oils used in aromatherapy: A systematic review. Asian Pacific Journal of Tropic Biomedicine, 5(8), 601-611.
- Lee, Y.L., et al. (2011). A systematic review on the anxiolytic effects of aromatherapy in people with anxiety symptoms. The Journal of Alternative and Complementary Medicine, 17(2), 101-108.
- Perry, N., & Perry, E. (2006). Aromatherapy in the management of psychiatric disorders. CNS Drugs, 20(4), 257-280.
- Wikipedia: Aromatherapy
There’s more about debunking pseudoscience on the science corner page.