With the passage of the 2018 Farm Bill bringing some measure of pseudo-legalization for low- or no-THC cannabis products, the American hemp industry has been booming. But just like cops can’t seem to tell hemp apart from low-grade schwag as it gets shipped around the country, so too is it difficult to distinguish if the push towards high-CBD, low-THC hemp products is the right move for the medical community.
Plenty of studies are being done on the neuroprotective potential of cannabinoids like CBD, leaving intoxicating THC in the proverbial ash. After all, something as fun as tetrahydrocannabinol can’t be medically helpful, right? Not in this year of our discoveries about carcinogenic wine?
Researchers at the University of New Mexico’s Department of Psychology seem to think otherwise. Scientific Reports recently published “The Association Between Cannabis Product Characteristics and Symptom Relief,” an article from a team at UNM suggesting that THC is more therapeutically important than people initially gave it credit for. The authors used data from ReleafApp—an app that tracks medical cannabis experiences by recording a smoker’s self-reported symptom relief, dosage and strain composition—to assess the improvement drivers in MMJ patients.
What’s more useful to patients, CBD or THC?
The team reported that “dried flower was the most commonly used product and generally associated with greater symptom relief than other types of products” like concentrates. They also found that “across product characteristics, only higher THC levels were independently associated with greater symptom relief and prevalence of… side effects” both negative and positive. Based on the information reported by ReleafApp users, “CBD potency levels were generally not associated with significant symptom changes or experienced side effects.”
The researchers also found that “higher starting symptom levels are associated with greater symptom relief” when looking at the three most commonly reported types of symptoms: anxiety, back pain and depression. The study found that when it came to treating depression, “greater symptom improvement” was reported from those smoking flower from 10 to 35 percent THC “relative to the least potent flower.” Reports of relief from anxiety symptoms increased very slightly between the lows and the mid-grade flower and then skyrocketed with the highest THC samples.
Interestingly, flowers with the highest levels of THC (19 to 35 percent) were reported to relieve back pain the least relative to the mid- (10 to 19 percent) and low-THC samples (0 to 9 percent). Granted, the study did not take into account the tolerance levels of smokers; it is reasonable to assume that people who regularly smoke high-grade cannabis for an ailment like chronic back pain have more of a resistance to high levels of THC and its possible medical effects.
Limitations of the UNM study
Though the researchers claim to have performed “the first study to measure how fundamental characteristics of cannabis products consumed in vivo affect immediate symptom relief and experienced side effects,” they used a self-reporting population that was “not cross-referenced with clinical assessments” and without controls. Moreover, THC and CBD data from cannabis testing labs have been found to contain inaccuracies.
Business Insider recently reported that many CBD products actually don’t contain as much CBD as they claim to (with some containing none at all), making it even more likely that people consuming non-flower CBD products aren’t getting the exact dose of the cannabinoid they’re promised. Obviously, this could negatively impact the effectiveness reported by cannabinoid users and might have contributed to the low numbers identified by the study—something that the researchers do address.
“Alternatively,” the researchers acknowledged, “it is possible that CBD has more latent effects than THC (e.g., expanding beyond the 90-minute observation window), has an impact on symptoms infrequently reported in our data or that CBD’s effects may not lend themselves to perceptual detection and subjective reporting.”
There’s no discussion in the study of ratios of CBD:THC in the samples, which has become an increasing point of interest for other researchers as it seems that the presence of CBD mediates the uptake of THC. It’s also been suggested that when present in equal levels, the two cannabinoids “[increase] clinical efficacy while reducing adverse effects” in what has come to be known as the entourage effect. “It is possible,” the UNM researchers wrote, “that while CBD may operate inconspicuously to improve certain health outcomes, the adjunctive consumption of THC is needed to consciously experience or be aware of effects.”
The researchers also admitted that “there is the potential confound of a placebo effect, and given that cannabis products advertised as containing higher THC contents are generally more expensive to consumers, they may be subject to a buyer’s justification effect (magnified appreciation to justify an added expense of purchase).”
Also, lest we forget, separating strains out into indicas and sativas is an exercise in meaninglessness geographic naturalism. Consensus among the modern scientific community is that Jean-Baptiste Lamarck’s 18th century sub-categorization of cannabis is overly simplistic, that is now outdated due to hybridization and simply “total nonsense and an exercise in futility” compared to performing an actual biochemical assay on a sample.
That being said, the study did find that “indica-based products are associated with a greater likelihood of reporting negative side effects and some evidence of fewer positive and more context-specific side effects relative to hybrid- and sativa-based products.” And despite the fact that the sativa/indica categorization has been challenged by scientists, reports of the effects of indicas “[matched] patient-reported preferences for… treating conditions such as pain and insomnia.”
In addition to potentially controlling for some of the aforementioned limitations, the UNM researchers suggest that, “Future research will capitalize on our ever-increasing sample size to analyze the pharmacodynamic interactions of major cannabinoids and other organic compounds including terpenoids, as well as the harm of cannabis production practices. For example, [how] the use of solvents to extract cannabinoids… may place patients at risk for respiratory and cardiovascular problems and be a cause of increased emergency cases of Cannabinoid Hyperemesis Syndrome.”
The researchers stress that “rapid increases in the popularity of medical cannabis and the associated increase in the number of patients highlight the urgency of investigating and directing effective usage.” They’re certainly right about that. There is a pressing need for more accurate and more rigorous scientific study of cannabis and its medical uses now more than ever and will only become more important as we strive to increase the body of knowledge on the various cannabinoids and their medical effects.
Photo credit: Elena Kulikova.