Aromatherapy review is technically inconclusive but the evidence is not promising

PainSci » bibliography » Lee et al 2012
updated Apr 13, 2023

Tags: treatment, massage, debunkery, hda, manual therapy, professions, modalities

PainSci commentary on Lee 2012: ?This page is one of thousands in the PainScience.com bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided wherever possible.

For this a review of other reviews, Dr. Edzard Ernst et al. found ten publications worth considering, only three of them any good, and even those were reviews of mostly quite low quality trials: “garbage in, garbage out” strikes again! The result was the inevitable inconclusive non-conclusion and/or negative: not much data in the first place, and what does exist is not convincing. Technically inconclusive, but not promising.

“Several systematic reviews of aromatherapy have recently been published. Due to a number of caveats, the evidence is not sufficiently convincing that aromatherapy is an effective therapy for any condition.”

But wait, what’s this now? Thanks to the black art of Actually Reading the Paper®, I found a positive statement about the results about massage and pain!

“Our overview suggests that aromatherapy, which generally delivered with massage therapy, may induce relaxation which, in turn, might improve pain and psychological health.”

Not exactly a ringing endorsement there, but a perfectly nice “might be something to it.” And I agree, for whatever my agreement is worth: I don’t really have any doubt that a pleasing smell can probably move the needle for pain patients a bit. I wouldn’t ever think of it a “treatment,” though — it’s just one of the more obscure instruments in an orchestra of peaceful sensations which can, temporarily, help to modulate pain.

~ Paul Ingraham

Common issues and characteristics relevant to this paper: ?Scientific papers have many common characteristics, flaws, and limitations, and many of these are rarely or never acknowledged in the paper itself, or even by other reviewers. I have reviewed thousands of papers, and described many of these issues literally hundreds of times. Eventually I got sick of repeating myself, and so now I just refer to a list common characteristics, especially flaws. Not every single one of them applies perfectly to every paper, but if something is listed here, it is relevant in some way. Note that in the case of reviews, the issue may apply to the science being reviewed, and not the review itself.

Garbage in, garbage out — not enough good quality data to meaningfully review/analyze.
Negative (or only barely positive) results despite a significant risk of bias that should tend to generate false positives.

original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.

Aromatherapy is the therapeutic use of essential oil from herbs, flowers, and other plants. The aim of this overview was to provide an overview of systematic reviews evaluating the effectiveness of aromatherapy. We searched 12 electronic databases and our departmental files without restrictions of time or language. The methodological quality of all systematic reviews was evaluated independently by two authors. Of 201 potentially relevant publications, 10 met our inclusion criteria. Most of the systematic reviews were of poor methodological quality. The clinical subject areas were hypertension, depression, anxiety, pain relief, and dementia. For none of the conditions was the evidence convincing. Several SRs of aromatherapy have recently been published. Due to a number of caveats, the evidence is not sufficiently convincing that aromatherapy is an effective therapy for any condition.

original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.

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