Every so often, the great minds that inhabit the National Academies of Science, Engineering, and Medicine produce an in-depth analysis of the current state of research and study of marijuana. The report, titled “Marijuana and Health“, was first supplied to the public in 1982 and has been through a total of three iterations. Going by the name “Marijuana and Medicine: Assessing the Science Base“, the second report was published in 1999.
January 2017 marked the third time the National Academies would publish an update into the known and unknown effects of cannabis. Titled “The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research“, the report spans over 400 pages and functions as an aggregate study. As the title suggests, the goal is to report the current place research is and the place it needs to be in order to appropriately assess health benefits and risks associated with cannabis and cannabinoids and limit them. Already a stunning departure from the “marijuana” titles of previous, the recognition of cannabinoids into the American social environment suggests the US population is more aware than ever that cannabis is not just THC.
The National Academies report on marijuana research study views into over 10,000 relevant abstracts that are already submitted, in good faith, to several relevant research and scientific databases, including Embase, Medline, Cochrane Database of Systematic Reviews, and PsycINFO. They were sorted by most recent, limited studies to those written in English and completely removing editorials, studies by unknown or “anonymous” authors, conference abstracts, commentaries, and case reports.
The team conducting the analysis are leaders of industry. A total of 16 committee members were called in to conduct the report. According to the report, experts in the following fields provided the analysis:
- respiratory disease
- pediatric and adolescent health
- preclinical research
- systematic review
- public health
As you may have noticed, that list includes researchers and review specialists, meaning that not only have some of the nation’s greatest medical staff reviewed the findings, but that the research can be deconstructed in reliability. As such, the report on marijuana research and study thus far has defined five criteria in rating the variable reliability of evidence to support or deny claims on certain therapeutic or adverse effects for both personal and public health:
Conclusive evidence is when high-quality study from a reputable source has several supportive findings with no quantifiable dispute. For therapeutic effects, there has to be strong evidence from controlled, randomized trials that cannabis does/ does not affect certain conditions. For other health outcomes, strong supporting evidence providing a statistical association is sufficient to support or refute the claim.
This more or less means that the study revealed more positively to one side, but in different studies around similar topics, there does appear be a low, yet noticeable, amount of scientific data that contradicts the supporting evidence. Factors of bias, chance, and other perplexities cannot be entirely ruled out.
This level of evidence is supported by good-to-fair studies, with limited amounts opposing studies. Again, factors such as bias cannot be completely ruled out.
The unfortunate reality of this study of marijuana research: it reports a ghastly number of studies that are of the low on the evidence scale. These are from fair quality studies that seem to favor one outcome. While this means there can be a measurable scientific affect, the risk of bias is a significant factor limiting the reliability.
No or Insufficient Evidence
As the name of this category suggests, the evidence of some health claims just have no way of verification. This means that the study was either poorly done, has not been replicated, or that there are mixed feelings.
The Eleven Health Topics
A study this massive is bound to have as much sprawl as the health claims commonly attributed to the use of cannabis. As a result, the design of the study also includes health endpoints, which are used to classify research done thus far, which can then be appraised for evidence credibility. They are:
- Respiratory Disease
- Injury and Death
- Prenatal, perinatal, and postnatal cannabis exposure
- Mental Health
- Problem cannabis use
- Cannabis and other drug use
The Results and Recommendations
In order to properly understand the limitations to the current landscape for cannabis within the United States, you first have to understand the limitations on research. I’m sure you are aware, marijuana remains illegal on the federal level. This alone makes study and research of marijuana less of a report and more of a constrained dance.
Medication studies often do take many years. For many studies in medicine, however the impediment isn’t the fact that it’s already illegal, but funding. In the case of marijuana, not only is it illegal, which hinders supply, demand, and consistency in procuring medical grade science flower, it is even harder to get funding. This makes the breadth of knowledge collectively worth more but also means that much of the research was too limited in scope to truly identify patterns with consistent supporting evidence. That being said, here’s the most significant findings:
- There is substantial and conclusive evidence that cannabis produces a clinically measurable reduction in pain in patients with chronic pain
- There is substantial evidence supporting cannabinoids role in lowering nausea and vomiting associated with chemotherapy
- There is substantial evidence suggesting cannabis can reduce muscle spasticity and lessen symptoms of multiple sclerosis
No other therapeutic effects had an adequate body of research to determine validity.
Smoke affects the lungs, but the way in which it does is disputed. The report on the study and research of marijuana shows the following:
- There is substantial evidence that smoking marijuana on a regular basis is associated with chronic cough (where you cough for longer than 8 weeks) and increased phlegm production
- Quitting smoking is linked to a reduction in chronic cough and phlegm production, dictated by moderate evidence
There is not enough evidence to support claims with asthma, COPD, or overall respiratory effect.
- There is moderate evidence that marijuana does not cause higher incidence of head, neck, or lung cancers
You may have heard that marijuana raises the heart rate. You may also have heard that raised heart rate can put stress on the heart, possibly leading to heart attack. But no worry:
- The limited to no evidence supporting or refuting claims of this nature, forcing us to ponder the effects of cannabis on the heart, with strokes, and diabetes
Effects on Immunity
- Limited evidence on the greater effects on human immunity exist, making it difficult to weed out bias
- There is limited evidence suggesting that cannabis can disrupt proinflammatory cytokines, making cannabis a possible anti-inflammatory drug
Effects on Injury and Death
- Substantial evidence suggesting cannabis use increases the probability of getting in a car accident
- There is moderate evidence that overdose injuries in children have risen since marijuana legalization
- Not enough evidence to determine effect on all-cause mortality or occupational injury
Effects on Neonates to Newborns
- There is substantial evidence that cannabis use while pregnant is linked to lower birth weight
- There is insufficient evidence to determine the effect on child developmental and skill attainment
- There is moderate evidence that cannabis can impair the cognitive centers where memory, attention, and learning occur
- There is limited evidence that cannabis use is associated with lower income, unemployment, and overall social well-being.
Effects on Problem Cannabis Use
- There is substantial evidence that ADHD medications and cannabis use are not linked
- There is substantial evidence that being male and smoking cigarettes impact problem cannabis use development
- There is moderate evidence that major depressive disorder, anxiety, bipolar, and other personality disorders are not factors that increase the risk of developing a cannabis use problem
Effects of Cannabis and other Drugs of Abuse
- Moderate evidence indicating the use of cannabis as a factor in development of a substance abuse disorder
Effects on Mental Health
Mental health is the final and most interesting place of study, research on marijuana effects report the following:
- Substantial evidence that schizo-typical illness can be exacerbated by cannabis use
- There is moderate evidence that marijuana can induce social anxiety and increase depressive symptoms
- There is moderate evidence that individuals with schizophrenia may experience increased performance in learning and memory tasks
As you can tell, the world of cannabis is pigeonholed by a fundamental lack of necessary public health information. While this report goes on to make four recommendations on how to best proceed, the rise of cannabis support is outpacing research. Whichever side of the legalization bandwagon you saddle up, more information is how we divine the best solutions to the path ahead, and the 2017 report on marijuana research was a study that was necessary to this end.