Aromatherapy May Make You Feel Good, But It Won't Make You Well

Or so says a study by researchers at the Ohio State University that is spreading rapidly throughout the Main Stream Media and the Internet and is being cited as proof that aromatherapy doesn't work. Although I found it first on a blog about the convergence of Mormon beliefs and science, a little searching revealed that it has been extensively reported on MSM web sites and the OSU Press Release describing the study has been widely reprinted (621 Google hits for the title above), the most significant of which is ScienceDaily.

The study, published online in the journal Psychoneuroendocrinology, looked for evidence that such aromas go beyond increasing pleasure and actually have a positive medical impact on a person’s health.  While a massive commercial industry has embraced this notion in recent decades, little, if any, scientific proof has been offered supporting the products’ health claims.

This could have as wide spread a circulation as the NEJM article on Gynecomastia which has been discussed extensively on this blog a year ago. And unfortunately, as happened in the prior situation, there will probably be very little coverage of any intelligent criticism or further discussion that we might have about the results of the study.

Most of the wider media coverage is based on the press release, and it's likely that very few persons will read the actual study, because of the exorbitant fee charged to download a copy. The aromaconnection blog has sprung for the cost and I have actually read the paper. I'll need a couple of days to digest it but we will definitely be commenting further on it. My initial evaluation is that the methodology is valid, but that a study that is limited to only two essential oils is not the same thing as "Aromatherapy", but of course over-generalizations have never been rare in the media world or the Internet.

The abstract/summary of the paper is:

Despite aromatherapy's popularity, efficacy data are scant, and potential mechanisms are controversial. This randomized controlled trial examined the psychological, autonomic, endocrine, and immune consequences of one purported relaxant odor (lavender), one stimulant odor (lemon), and a no-odor control (water), before and after a stressor (cold pressor); 56 healthy men and women were exposed to each of the odors during three separate visits. To assess the effects of expectancies, participants randomized to the “blind” condition were given no information about the odors they would smell; “primed” individuals were told what odors they would smell during the session, and what changes to expect. Experimenters were blind.

Self-report and unobtrusive mood measures provided robust evidence that lemon oil reliably enhances positive mood compared to water and lavender regardless of expectancies or previous use of aromatherapy. Moreover, norepinephrine levels following the cold pressor remained elevated when subjects smelled lemon, compared to water or lavender. DTH responses to Candida were larger following inhalation of water than lemon or lavender. Odors did not reliably alter IL-6 and IL-10 production, salivary cortisol, heart rate or blood pressure, skin barrier repair following tape stripping, or pain ratings following the cold pressor.

If you'd like to find the paper on the Internet, you can find it on ScienceDirect by entering the keyword Aromatherapy. Right now it is the first entry.