Aromatherapy is one of the most popular of all alternative therapies. It is most certainly a very agreeable experience. But is it more that a bit of pampering? Does it cure any diseases?
If you believe aromatherapists, their treatment is effective for almost everything. And, of course, there are studies to suggest that, indeed, it works for several conditions. But regular readers of this blog will by now know that it is a bad idea to go by just one single trial; we always must rely on the totality of the most reliable evidence. In other words, we must look for systematic reviews. Recently, such an article has been published.
The aim of this review was to systematically assess the effectiveness of aromatherapy for stress management. Seven databases were searched from their inception through April 2014. RCTs testing aromatherapy against any type of control intervention in healthy but stressed persons assessing stress and cortisol levels were considered. Two reviewers independently performed the selection of the studies, data abstraction and validations. The risk of bias was assessed using Cochrane criteria.
Five RCTs met the authors’ inclusion criteria. Most of the RCTs had high risk of bias. Four RCTs tested the effects of aroma inhalation compared with no treatment, no aroma, and no odour oil. The meta-analysis of these data suggested that aroma inhalation had favourable effects on stress management. Three RCTs tested aroma inhalation on saliva or serum cortisol level compared to controls, and the meta-analysis of these data failed to show significant difference between two groups
The authors concluded that there is limited evidence suggesting that aroma inhalation may be effective in controlling stress. However, the number, size and quality of the RCTs are too low to draw firm conclusions.
This is by no means the only systematic review of this area. In fact, there are so many that, in 2012, we decided to do 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. Our conclusion: due to a number of caveats, the evidence is not sufficiently convincing that aromatherapy is an effective therapy for any condition.
So, what does all of this mean? I think it indicates that most of the claims made by aromatherapists are not evidence-based. Or, to express it differently: aromatherapy is hardly more than a bit of old-fashioned pampering – nothing wrong with that, of course, as long as you don’t fall for the hype of those who promote it.