The cannabis essential oil is one of the most promising in terms of market expansion and the industrial potential. Derived from industrial hemp with less than 0.2% of tetrahydrocannabinol (THC), this oil has already proven useful in the cosmetic and food industries.
Cannabis essential oil is mainly composed of volatile substances, mainly monoterpenes, sesquiterpenes and other terpene-like substances.
There is still very limited data on what effects cannabis essential oil may have on the brain. Evidence suggests there may be positive effects, but could there be negative consequences as well?
The area with the largest potential for medical benefit resides in emotional response. The psychoactive effects of cannabis have been well documented, but those effects could produce chemical changes that lead to emotional responses. The most obvious comes in the form of mood elevation. Inhalation of cannabis essential oil provides near instantaneous temperament improvement. This has the potential to serve patients who suffer from depression or anxiety, but may serve the population more generally as well. One compound responsible for this beneficial effect is the terpene limonene, which has demonstrated similar uplifting benefits in mice.
In a related vein, many cannabis users report using cannabis to help stimulate relaxation or sleep. Meaning cannabis essential oil may make subjects happier, but also more physically comfortable to the point of stimulating somnolence. One theory for this is that cannabis essential oil can act as an analgesic. Pain relief alone is not enough to be conducive to sleep or relaxation, but it may signal physical responses that help to facilitate these. These physical effects would be in addition to the other emotional reactions coming both from cannabinoids and terpenes. Cannabis essential oil can also produce calming and energizing effects. This may be attributed to other terpene compounds found within the cannabis oil, specifically myrcene and β-caryophyllene, which demonstrate these results in mice.
All of these emotional outcomes would ultimately be seen as beneficial to various users. Increased well-being, relaxation, and pain relief are difficult to argue against. The only issue may lie in the potential for abuse, but that would fall to individual users and may not represent the population as a whole.
The Nervous and Digestive Systems
In addition to the emotional reactions, cannabis essential oil may stimulate various responses throughout the rest of the body. These are most noticeable in both the nervous system and the digestive system. Following the inhalation of cannabis essential oil, 60% of subjects tested saw increased heart rate, but at the same time 80% of the same subjects saw a drop in diastolic blood pressure.
The most likely terpene responsible for these reactions, pinene, has been shown to elicit responses both the autonomic nervous system and parasympathetic nervous systems. This is because pinene has the potential to inhibit acetylcholinesterase, which may account for the drop in diastolic blood pressure. This evidence is corollary though, and more data is needed at this time to confirm this finding. The other major change within the nervous system came from body temperature rising.
While these effects to the physical body appear to be minor, they may represent a more sinister problem. Any substance that has the potential to alter heart rate or blood pressure could exacerbate conditions related to heart health or could induce feelings of panic. In the case of the digestive system, the primary consequence of cannabis essential oil use is an increase in appetite. This does not present a major health concern, but this may be a negative for certain users. For others, like cancer or HIV patients who may lose their appetite as a side effect of their medications, this essential oil may serve a powerful medicinal benefit.
Mapping electroencephalogram (EEG) changes provides the most accurate picture of how cannabis essential oils stimulate changes in brain activity. One study measured changes across α, β 1, β 2, δ, and θ frequency bands to determine changes in amplitude and relative power. the study found various changes to the effects of brain waves in various parts of the brain, but what does this signify? Following the inhalation of cannabis essential oils, the changes to the EEG were similar to individuals who practiced meditation, yoga, or other mindfulness practices. This is especially prominent with the increases in both α and θ frequency bands, but this also can produce additional medical benefits. Long form meditation has been shown to increase levels of serotonin, noradrenaline, melatonin, dopamine, and cortisol in its practitioners. When comparing this to the emotional responses provided by various terpenes, the results are promising.
Each of these hormones can produce similar effects as the terpenes including pain relief, mood elevation, relaxation, well-being, and drowsiness. Evidence is still inconclusive about how much of a role the cannabinoids play compared to the terpenes, but it could be the case that the two augment and elevate the effects of the other. What the EEG results prove is that there is an additional benefit to cannabis essential oils beyond just relying on the terpenes alone. What the study concluded is that there is very strong evidence that cannabis essential oil can serve a purpose in treatments for anxiety and depression related disorders. This study is only preliminary and encourages more research to be done to confirm the data with larger sample size.