Some nice finds! I was excited to think that my view of aromatherapy might be overturned.
By the time I finished researching, my excitement had worn off.
Randomized trial of aromatherapy. Successful treatment for alopecia areata.
I was a bit surprised by this study, as the treatment was rubbing oils into the affected areas (scalp), which seems to me to be less about the "influence of aroma on the brain, especially the limbic system through the olfactory system" (Wikipedia) and more about topical application of drugs. This seems far less implausible, but apparently it still counts as aromatherapy.
The study was examined in June 2000 in Aromatherapy: a systematic review, Brian Cooke and Edzard Ernst,
British Journal of General Practice, 2000, 50, 493-496.
In it, they classified it as one of six "‘one-off’ trials of aromatherapy with no independent replication."
The studies were too heterogeneous and had no common
denominator in terms of end-point evaluated for meta-analysis to
be attempted. The highest Jadad score achieved in any of these trials was 2 (out of a possible 5).
While the implication about Jadad scores is unfortunate, asking for independent replication so soon after the study came out strikes me as a little unfair. I looked for some later reviews.
I found this:
Aromatherapy with essential oils (thyme, rosemary, lavender, and cedarwood) massaged daily
was compared with carrier oil in 86 people with alopecia areata and they were followed up after
3 months and 7 months [Hay et al, 1998]. Independently assessed photographic evidence was
collected throughout the trial and any degree of improvement was measured using a six-point scale
and computerized analysis of affected areas. Nineteen people in the active treatment group (n = 43)
showed improvement, compared with six people in the control group (n = 41), which was a highly
significant difference. However, the study had several limitations:
- It was not clear how long the treatment was given for.
- Thirteen people dropped out of the control group, reducing the impact of the apparent
benefit achieved with aromatherapy.
- Some people had other types of treatment before the study was discontinued but no more
details were provided.
- It is assumed that the treatment and intervention groups had similar baseline profiles in
terms of extent and pattern of alopecia areata but details were not provided.
- Note: manufacturers of aromatherapy products are not bound by statutory monitoring or
good manufacturing requirements and there is no formal recognized standardization of
active ingredients in aromatherapy products.
Complementary and alternative medicines: use in skin diseases, Magin, Parker; Adams, Jon, Expert Review of Dermatology, Volume 2, Number 1, February 2007 , pp. 41-49(9)
I looked for a Cochrane Review (see below for what they are) to see if, perhaps, one of the oils used is considered a conventional, topical treatment for alopecia areata. I found that there are no known good treatments:
Treatments for alopecia areata, alopecia totalis and alopecia universalis
There is no good trial evidence that any treatments provide long-term benefit to patients with alopecia areata, alopecia totalis and alopecia universalis.
[...]
We found 17 randomised controlled trials involving 540 participants. Only one study which compared two topical corticosteroids showed significant short-term benefits. No studies showed long-term beneficial hair growth. None of the included studies asked participants to report their opinion of hair growth or whether their quality of life had improved with the treatment.
Delamere FM, Sladden MJ, Dobbins HM, Leonardi-Bee J, Interventions for alopecia areata, Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD004413. DOI: 10.1002/14651858.CD004413.pub2
So, this study has been criticised for a number of reasons and dismissed. My conjecture that the oils themselves (and not their aromas) might have some effect is not supported by evidence.
Aromatherapy as a safe and effective treatment for the management of agitation in severe dementia
This is the study that got me excited, because I couldn't see any immediate flaws myself.
It's a small study, so I went to the Cochrane Collaboration to see how it fit in with other studies in the area. Cochrane are a highly respected organisation that do meta-analyses, examining all the published studies in an area to review their methods and to pool their data.
In 2003, (and still up-to-date as of 2008), they published a short review on the topic of aromatherapy and dementia.
The one small trial published is insufficient evidence for the efficacy of aroma therapy for dementia
Aroma therapy is the use of pure essential oils from fragrant plants (such as Peppermint, Sweet Marjoram, and Rose) to help relieve health problems and improve the quality of life in general. The healing properties of aroma therapy are claimed to include promotion of relaxation and sleep, relief of pain, and reduction of depressive symptoms. Hence, aroma therapy has been used to reduce disturbed behaviour, to promote sleep and to stimulate motivational behaviour of people with dementia. Of the four randomized controlled trials found only one had useable data. The analysis of this one small trial showed a significant effect in favour of aroma therapy on measures of agitation and neuropsychiatric symptoms. More large-scale randomized controlled trials are needed before firm conclusions can be reached about the effectiveness of aroma therapy.
Holt FE, Birks TPH, Thorgrimsen LM, Spector AE, Wiles A, Orrell M. Aroma therapy for dementia. Cochrane Database of Systematic Reviews 2003, Issue 3. Art. No.: CD003150. DOI: 10.1002/14651858.CD003150
They go on to explain: They looked at four published papers, including Ballard 2002 (i.e. the one you cite), and found none of them could be used as is, but they went and requested the data from the authors of the Ballard study and re-did the statistics, and confirmed it did show a statistically significant treatment effect.
Inhalation Aromatherapy During Radiotherapy
If we quote a little bit more of the abstract we get a very different result:
Results: There were no significant differences in HADS
depression or SPHERE scores between the randomly assigned
groups. However, HADS anxiety scores were significantly
lower at treatment completion in the carrier oil only
group compared with either of the fragrant arms (P = .04).
Conclusion: Aromatherapy, as administered in this
study, is not beneficial.
Note: This indicates, if anything, that aromatherapy is harmful (causes anxiety), compared to the control.
There appears to have been some unblinding due to the fragrance, so even that result isn't terribly convincing; see Table 1 and also the statement:
None of the patients in the carrier
oil–only arm requested dose reductions (achieved by using
fewer drops); whereas, 35% of the patients in the fragrant arms
requested this because of the initial strength of the olfactory
sensation.
