The medicinal properties of essential oils have been “under the microscope” for some time. Many of their therapeutic properties from a biochemical standpoint are well established, but the “aroma-therapeutic”actions are a little more challenging to research. Many folks believe essential oils can brighten our minds, but can it be proved? Or is it all in our heads? It turns out there’s a growing amount of evidence that essential oils can, under scientific scrutiny, improve our mental acuity and our moods.
Essential oils can loosely be classified as “stimulating”, “sedating” or “neutral”. Many of the stimulating oils seem to share certain effects on the nervous system in a biochemical manner. And by definition, they share effects on alertness and mood. The great thing being that “aromatherapy” that was once laughed at, is now being backed by rigorous research, and the connections between the biochemical actions and the psychological actions are being elucidated.
The latest research (published in October 2010) on sage essential oil is almost revelatory. Researchers at the Brain, Performance and Nutrition Research Center of Northumbria University, in the United Kingdom, used a battery of tests to determine the efficacy of the ingestion of one drop of sage. They employed a “a double-blind, placebo-controlled, balanced crossover study” to examine the “effects of a single dose on cognitive performance and mood”. This type of study tests the same individuals with and without a placebo, over the course of several sessions, to truly confirm the effects.
The results are very enlightening for the aromatherapy practitioner. With just one single drop, measurable, statically significant improvements in both mood and memory-related tasks were found (most notably at one-hour post ingestion). At four hours after ingestion, measurable reduction of mental fatigue was found. This seems that a really small amount of essential oil produced these results! And because the drop was ingested, it’s all about getting the oil in the bloodstream any way you can — which actually happens via inhalation and topical application as well. So what’s going on here?
The reason for these cognitive and mood improvements are not completely clear — however, the researchers point to the observation that sage, and in fact many other spicy/herbal essential oils, inhibit an enzyme in the body that breaks down acetylcholine. This is our primary “information processing” neurotransmitter, and when these essential oils are in the bloodstream, they allow more of this neuro-chemical to be available. This is the same activity of an herbal supplement called “Huperzine A”, also taken to improve brain function.
Also of interest is that it seems to be an entire class of chemicals, called “monoterpenes” that have this action. They contribute to bright, high notes in aromas. They’re found in citrus oils as well, particularly in lemon essential oil. And lemon has been the subject of similar research (as that done with sage), with similar results. And as the sage study noted, these natural chemicals that act as aromatic stimulants when inhaled act as mental stimulants when ingested as well. (It’s unclear whether peppermint, for example, enhances cognitive function through ingestion, though it has been shown to do this through inhalation).
So how to go about using these essential oils for improved mental performance yourself? The abstract of the research involving sage essential oil indicated the results were due to ingesting a single dose of 1 drop of oil. While you’ll see a lot of conflicting opinion about ingesting essential oils, virtually everyone can agree that ingesting 1 drop on occasion is safe for all but the most spicy oils (cinnamon or oregano). Understanding how essential oils are actually absorbed in the bloodstream through inhalation and topical application, it would seem truly that any way you’d like to use these types of oil for improving cognitive function is reasonable. (Use of sage essential oil is not recommended during pregnancy or by young children due to its ketone content — but there are many other oils to choose from!) Whichever you do choose, remember that essential oils are potent, and successful use virtually always adheres to the “less is more” principal.
The author is proponent of the varied and potent healing actions of aromatherapy essential oils. For more, see www.anandaapothecary.com/essential-oils.html.