Issue 21
June 2014
Supplemental Science Sources Review by Lori L. Barr In any field of study and practice, there is a tendency to think that the important research is published in journals where findings are reviewed by specific peers. The truth is that awareness of discoveries in other fields sparks innovation within a discipline. With this in mind, the ARC Board offers the following introduction to scientific reports that might impact the field of Aromatherapy. Below are synopses of major findings, their relevance to the aromatherapist, and complete citations to the complete articles.
processes currently used and that there are no standardized tests for the evaluation of antibacterial activity of essential oils. The major limitation is that high viscosity and water insolubility make for irregular distribution and unequal dilution of the essential oil throughout the culture media. The article then expounds on the seven key factors in essential oil activity evaluation.
“Effect of Essential Oils on Pathogenic Bacteria.” Pharmaceuticals, December 2013. (Free on-line.)
This article summarizes the current body of knowledge regarding odor perception and attached emotional memories. Functional Magnetic Resonance Imaging (fMRI) allows researchers to map how the brain responds to sensory input. The mapping that is now available for olfaction helps to explain how some odors modulate emotion and cognition. There is good evidence that the sense of smell may be an effective, often subconscious emotional driver. In addition, there is good evidence that the autonomic nervous system relaxes with exposure to smells deemed safe or pleasant by the person doing the smelling. Of particular note is the discussion on the perception of odor that details the role of the piriform cortex to both group together similar odors and separate out individual odors.
The growing resistance of microorganisms to prescription drug therapy has prompted interest and research in plants and their derivatives. This article summarizes the current theories and science surrounding the ways essential oils interact with pathogenic Gram-negative and Gram-positive bacteria. It summarizes the effects of essential oils on bacteria and then dives deep into the current knowledge of mechanisms of action on cells, beginning with the cell membrane and moving from cell shape deep inside to the genes and proteins that compose the cells. It ends with a discussion of how essential oils are promising as agents that are anti-pathogenic and do not encourage resistance strain development because they decrease the ability of bacteria to communicate to each other and to higher organisms through quorum sensing (think social media on the cellular level). While this summary is accurate, it does not describe the limitations in performing research on the effects of essential oils on bacteria. “The Mode of Antibacterial Action of Essential Oils.” Science Against Microbial Pathogens: Communicating Current Research and Technological Advances. 2011. (Free on-line.) This chapter does a fantastic job of summarizing the factors that influence the determination of antimicrobial activity in section 3.1. It really helps the reader who might not be a microbiologist to understand the laboratory and experimental conditions of the research that is reported in the literature. The article explains the origin of the
“Effect of Odor on Emotions, with Implications.” Frontiers in Systems Neuroscience, October 10, 2013. (Free on-line.)
National Cancer Institute: PDQ® Aromatherapy and Essential Oils. October 16, 2012. (Free on-line.) This PDQ Cancer Information Summary on Aromatherapy and Essential Oils is the current assessment of aromatherapy from the perspective of scientific and medical investigators funded by the United States government in the field of cancer research. It is interesting to view the filed of aromatherapy from their perspective. The information is somewhat dated and anyone who believes that the information is not accurate is able to give the committee feedback as instructed on the site. Probably the most useful information for aromatherapists is the table entitled “Use of Aromatherapy as a Supportive Care Agent in Cancer and Palliative Care Table of Clinical Studies.” This table summarizes published clinical trials along with the rigor of the study design in the seventh column. The lower the level (Continued on page 2)