March 24, 2008
Pacific Institute of Aromatherapy Response to OSU Aromatherapy Study
Dr. Kurt Schnaubelt responds in detail to the OSU Aromatherapy Study at the Pacific Institute of Aromatherapy site (scroll down the page to find the article entitled "Aromatherapy Won't Make You Well, Study Shows or creating sensations by omission"). He distinguishes three aspects of the paper: The factual paper itself; the popular rendition in the press release as reprinted "ad nauseam"; and thirdly the issues
that can be raised about the purpose and meaning of a recent trend, in which studies like the one discussed here aggressively prove the lack of efficacy of natural remedies. In recent times a number of well financed and immaculately organized studies have reported that the efficacy of various important phyto pharmacons does not exceed that of placebo. Plant medicines demoted in this fashion include St Johnswort, Echinacea, Saw Palmetto and Black Cohosh and soon probably also Gingko. Publication of the negative results generally appear in high level medical journals and spawn endless repetitions in scientific journals as well as the mainstream press generating the impression that somehow all the inherited wisdom about plant medicine is a figment of the imagination, unfit to perform under scientific scrutiny. The aspect entirely omitted from this discussion is that the methodology of the studies is entirely unsuitable to demonstrate the efficacy of neither the whole therapeutic approach of phytotherapy (or for that matter aromatherapy) nor that of a selected plant extract.
Dr. Schnaubelt points out some of the shortcomings of the study and that the parameters studied "do . . . not truly relate to suggestions the aromatherapy literature makes about these two oils."
He takes on the Science Daily rewrite (which, as we have pointed out here, is actually an almost verbatim copy of the OSU Press Release) with pithy analysis closing with "If cultural critics were to look for a perfect example of rampant scientism, here is one!"
He then goes into a detailed discussion of the definition of Aromatherapy, the rejection of plant medicine by the pharmacological industry, and goes on to suggest that liver detoxification enzymes evolved as a response to the need for mammals to process out the essential oils in new plants they are eating.
It is ironic that plants are the native substrates having triggered the evolution of this enzyme system, which also removes the vast majority of all synthetic drugs. In todays medical literature this very enzyme system is generally referred to as drug metabolizing (!) enzymes creating the impression that somehow the removal of the synthetic drug is a feature that comes with its purchase.
This article is well worth reading and deserves a large audience. It's too bad we can't get it as widely exposed as the OSU press release that stimulated it.
March 17, 2008
The OSU Aromatherapy Study-- the real story
Two recent posts (here and here) have documented the publication of a study entitled "Olfactory influences on mood and autonomic, endocrine, and immune function" and an accompanying press release about it entitled "AROMATHERAPY MAY MAKE YOU FEEL GOOD, BUT IT WON’T MAKE YOU WELL". There have been a number of comments from Aromatherapists on some blogs and mailing lists about the study--mainly based on the press release. Although we are not necessarily defending the study here we feel that the study should be judged on its own merits (or deficiencies) and not on what the OSU Public Relations department has released to the public.
What the study is about
In the introduction the the paper, the authors cite two main references (Price and Price, 1999) and (Hirsch, 2001) with a few others, to define what aromatherapy is, and effectively limit the scope to inhalation aromatherapy, although that is not specifically stated. They cite three mechanisms for how aromatherapy works: Systematic effect theory that "posits that essential oils act like a drug or enzyme", immune function enhancement, and relaxation. They state that "efficacy data are scant, and potential mechanisms of action are controversial." After briefly reviewing some of the literature for lavender, lemon, and placebo (the three oils of choice for the study) they then set forth the exact parameters that they felt defined the study:
To compare and contrast the diverse perspectives about whether and how odors affect health, we examined the autonomic, endocrine, and immune consequences of one purported sedating or relaxant odor, lavender, one activating or stimulant odor, lemon, and distilled water as a no-odor control during both resting and “challenge” or stress conditions in a mixed or between-within repeated measures design; each subject served as his or her own control during three separate 6 h[our] visits. Depending on their random assignment, participants were either given no information about what odors they would be smelling or what to expect (the “blind” group), or they were told what odors they would smell and what changes to expect from the relaxant, stimulant, or no odor exposures (the “primed” group).
Our protocol for each session included a cold pressor, a laboratory stressor that elevates stress-related hormones, heart rate, and blood pressure (Blandini et al., 1995; Hirsch and Liebert, 1998). Both before and after the cold pressor we performed tape stripping, a common dermatological paradigm for studying restoration of the skin barrier, a process mediated by both endocrine and immune systems (Choi et al., 2005). Our design thus provided a way to examine the ability of lemon and lavender odors to modulate stress and pain responses to the cold pressor, as well as wound healing via the speed of skin barrier repair.
In summary, they evaluated two essential oils and a water placebo via inhalation and measured some physiological parameters to determine if there were actual effects. The final paragraph of their introduction summarizes the predictions of results that they expected to obtain from the study and defines the parameters to be measured:
Specific predictions can be derived from the various theories posited to explain the effects of essential oils. For example, if the systemic effect theory is correct, even relatively short-term exposure to lavender would be expected to produce larger declines in the production of cortisol and catecholamines, faster skin barrier repair, lower pain ratings in response to the cold pressor, and smaller stress-related immunological changes compared to lemon and the no-odor control; short-term exposure to lemon oil should produce greater transient increases in positive affect, heart rate, blood pressure, and catecholamines than either lavender oil or the no-odor control. If expectancies determine the pattern of responses (Jellinek, 1997), then the primed group's mood and physiological responses to lemon and lavender odors would be greater than the blind group; similarly, those with positive expectancies about aromatherapy in advance of participation would be expected to show greater changes. By assessing olfactory influences on mood and autonomic, endocrine, and immune function, our design allowed us to contrast these diverse conceptual perspectives, clarify mechanisms, and assess possible clinical efficacy.
I'm probably push the boundaries of fair use in my quoting, but I want to be fair to the authors and it's really hard to summarize this stuff very well. See what happened when they tried at the OSU Public Relations department, or even in the summary to the paper.
I've reviewed the methodology and won't go into detail here, other than to summarize. They had 56 participants in the study; they excluded people who might have adversely affected the study (such as those with no or a reduced sense of smell); they attempted to control any variations in methodology by standardizing the application of the oils and the measurements. One thing that I initially questioned was that they froze the essential oils (at -80C) and thawed only enough to use at the time of a session, but they did perform MSGC's on the oils at the beginning and periodically throughout the study to verify that there were no changes. Dr. Robert Tisserand assured us that freezing should not be a problem causing variability. They obtained their essential oils from a Chemical Supplier, but they provided no specific lot or country of origin data. The vendor has online data available for other lavenders (a 40/42 that came from Russia, for example), but not for this one. The vendor has two lemon oils, but neither has the correctly spelled botanical name and it's not clear which one was used. There is no evidence in the paper that the oils used were appropriately of aromatherapy quality.
The paper describes in detail exactly how they measured each of the parameters; how the experimenters were blinded so they couldn't tell which odor was being used, and how the data were gathered. I'm not going to go into detail here; the methods appear to be adequate to the non-expert. They've stated their methods of statistical analysis in general terms. Since the study was peer-reviewed, we should probably assume that they got the data analysis right.
The method of application of the odors has been questioned. Since they applied the odor to the participants for a period of several hours, and during that time the participants were being tested, they needed a standardized way to apply it. So they applied 100 microLiter of the EO to a cotton ball and taped it between the nose and the upper lip on top of a piece of surgical tape barrier to avoid absorption through the skin. What wasn't made clear in the press release was that they replaced the cotton 4 times [at irregular intervals] during the study period to maintain odor strength and they removed the cotton ball for a lunch break, then applied a new cotton ball to complete the testing.
Another potential issue was the mention in the paper of placement of a "heparin well" in the arm of each participant at the beginning of the session and its removal at the end. Since heparin is a chemical anticoagulant (that has been in the news lately because of bad material imported from China), we were concerned that its presence might bias the results. However, a Google search revealed that the well is merely an IV tube that is placed to allow easy access for taking blood samples during the study. Apparently it's a common practice during research at OSU. There was no heparin introduced into the body during the testing.
The results listed in the study summary were summarized so as to be difficult to understand to the lay reader. The authors presented the results of each of the tests in either descriptive or graphical form. The results are subject to interpretation and that is done in part 4 of the paper, entitled Discussion. That will be covered in a future post.
Summary of Problems observed by me:
- The source and characteristics of the Essential Oils used were not adequately stated and tracked. The authors took care to maintain the oil quality during the study, but there is no way to tell whether the oils were any good to start with. MSGC data should have been included in the paper as well.
- The odor strength was not uniformly and consistently maintained because the interval between changes was not standardized, and because of the lunch break. Even if it had been, it can be questioned as to whether it should have, since intermittent application is the usual mode in aromatherapy.
- The practice of continuous application of the odorant materials during the entire test is not in accord with my understanding of normal aromatherapy practice, although the paper seems confused on the issue, citing one intermittent study (Goel et al., 2005) and one with "short term inhalation," whatever that means.
- No trained aromatherapist was apparently consulted about the study. It might also have been useful to have the opinion of a trained aromatherapist as to the quality of the oils used and their suitability for aromatherapy.
(only these mentioned in this post are included here--the full paper has 41 references listed).
Blandini et al., 1995 F. Blandini, E. Martignoni, E. Sances, G. Bono and G. Nappi, Combined response of plasma and platelet catecholamines to different types of short-term stress, Life Sci. 56 (1995), pp. 1113–1120. Abstract | Full Text + Links | PDF (595 K) | View Record in Scopus | Cited By in Scopus (11)
Choi et al., 2005 E.-H. Choi, B.E. Brown, D. Crumrine, S. Chang, M.-Q. Man, P.M. Elias and K.R. Feingold, Mechanisms by which psychologic stress alters cutaneous permeability barrier homeostasis and stratum corneum integrity, J. Invest. Dermatol. 124 (2005), pp. 587–595. View Record in Scopus | Cited By in Scopus (25)
Hirsch, 2001 A.R. Hirsch, Aromatherapy: art, science, or myth?. In: M.I. Weintraub, Editor, Alternative and Complementary Treatment in Neurologic Illness, Churchill Livingstone, Philadelphia, PA (2001), pp. 128–150.
Hirsch and Liebert, 1998 M.S. Hirsch and R.M. Liebert, The physical and psychological experience of pain: the effects of labeling and cold pressor temperature on three pain measures in college women, Pain 77 (1998), pp. 41–48. Abstract | Full Text + Links | PDF (60 K) | View Record in Scopus | Cited By in Scopus (13)
Jellinek, 1997 J.S. Jellinek, Psychodynamic odor effects and their mechanisms, Cosmet. Toilet. 112 (1997), pp. 61–71.
Price and Price, 1999 S. Price and L. Price, Aromatherapy for Health Professionals, Churchill Livingstone, Edinburgh (1999). Here in Google Books.
Tisserand, 2008 Robert Tisserand, Personal Communication to blog author.
March 06, 2008
Aromatherapy Study portrayal on the blogs
The Ohio State University aromatherapy study press release referenced in the previous post, in spite of the fact that it actually confirmed that at least one essential oil, lemon, has an actual aromatherapy effect, is being reprinted or referenced in various blogs as proving that aromatherapy doesn't work.
Here are some of the titles of blog posts and Main Stream Media (MSM) articles picked up by a Google alert for the word "aromatherapy" (I'm not doing links, since most of the items are the same article):
- Aromatherapy may make you feel good, but it won't make you well (original Press Release Title currently at 892 hits--Click here to see the list) UPDATE: Wow! 13,100 hits at 5 pm Saturday UPDATE2: The number has dropped as of 3/25. Apparently Google refined the search.
- Study Finds Aromatherapy Doesn't Work
- Aromatherapy can cheer, not heal
- No advantages from Aromatherapy?
- Aromatherapy Doesn't Fix Body, Study Says
- Aromatherapy Stinks - kind of - and Other News
- Aromatherapy's Effectiveness Questioned
- Two Aromatherapies Don't Work
- Aromatherapy Doesn't Work?
- Aromatherapy can cheer, but not heal, says study
- Does Aromatherapy Work?
- Doubts cast over aromatherapy in new study
- Does Aromatherapy Really Work?
- Study Questions Effectiveness of Aromatherapy
- Aromatherapy has no physical effects
- Do Aromatherapy Products Work?
- Aromatherapy Falls Short, Study Finds
- Experimental Evidence Supports Runner's High; Aromatherapy...Not...
- Aromatherapy is Woo
- Aromatherapy, a Bunch of foolery?
- Aromatherapy is Bullshit Malarkey, Sez Prof. Malarkey! (And He Should Know!)
- No Advantages from Aromatherapy?
- A whiff of scent is no cure for what ails you
I could continue for a long time if I go on to related stories that Google doesn't index directly. And I actually found a few benign headlines. Pravda, for example, has a neutral title: "New study evaluates efficacy of aromatherapy." Another article is entitled: "Aromatherapy makes you feel good, study."
These headlines are an indication that the authors of these blogs didn't actually read the article, or if they did read it selectively. It's a problem with blogging--you need to put a unique title (or so you think) and so you scan the article, throw out a title that reflects your first impressions, post the article, and move on. It's our policy on this blog not to directly reprint an article that someone else has already posted, without their permission. Particularly if we can link to it, which is usually the case. But a lot of aromatherapy bloggers, or anti-aromatherapy bloggers, don't have those scruples. Writing something original about something is hard work. Copying it and putting your name on something is easy--and it's also plagiarism. The several hundred newspaper reprints of the press release with the same title are probably not plagiarism, since it probably went out over the wire.
Anyway, this is what we have to put up with. . . .
March 05, 2008
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.