While scientific research of cannabis’ medical properties was hampered by Prohibition, significant research has been conducted on a global scale. On PubMed.gov, a database maintained by the National Center for Biotechnology Information, there are nearly 25,000 studies referencing cannabis. Many of those studies were conducted within the past 5 years, highlighting just how much exciting activity has cropped up around the plant
Given the breakneck pace of research, it can be hard to keep tabs on the most recent developments. These 10 recent medical cannabis studies are helping us better understand this complex plant and how it can support health and wellness.
1. Cannabis sativa and anti-microbial effects
There has been a significant amount of research into the anti-microbial effects of cannabis, concerning both phytocannabinoids and terpenes. An April 2021 review of these studies published in Pharmacology Research & Perspectives determined that Cannabis sativa varieties of the plant are especially effective for anti-microbial purposes.
Past studies have found multiple compounds – including the cannabinoids delta-9 Tetrahydrocannabinol (THC), Cannabidiol (CBD), Cannabichromene (CBC), Cannabigerol (CBG), and Cannabinol (CBN) – are powerful anti-microbials. Future studies geared toward how these phytocannabinoids work, as well as how they may augment one another, should reveal additional insights into how cannabis and cannabis-derived extracts can treat bacterial and fungi associated conditions.
2. The neuroprotective properties of CBD
Cannabidiol (CBD) is a household name for its many purported benefits. One of the most striking, however, is its neuroprotective potential – researchers are beginning to unravel the mystery behind how CBD can prevent and forestall neurodegenerative conditions.
Researchers articulated in an article published in the Federation of American Societies for Experimental Biology Journal the way in which CBD helps to slow down cognitive decline and prolong life in people living with neurodegenerative conditions. This is particularly important to the study of Alzheimer's disease and potential novel treatments for other forms of dementia. In 2021, researcher might delve further into this topic, hoping to determine how to harness the mechanism of action observed in CBD for the treatment of neurodegenerative conditions.
3. Cannabis and brain cancer treatment
Researchers examined the potential of phytocannabinoids as part of a combination treatment targeting a rare and aggressive form of brain cancer known as glioblastoma multiforme (GBM) in a March 2021 review of existing scientific studies published in the International Journal of Phytotherapy and Phytopharmacology. The review of 14 scholarly articles included 5 in vitro studies, 2 in vivo studies, and 7 studies that included both in vitro and in vivo aspects.
The review concluded that phytocannabinoids indeed possess anti-cancer properties and were able to arrest or reduce tumor growth rates in both mice and humans. However, the researchers acknowledged that to improve the accuracy of scientific knowledge, further human trials on a larger scale are needed.
4. Measuring for the placebo effect
An April 2021 study published in Psychopharamacology put the anti-anxiety effects of CBD to the test, in which 43 participants were asked to take a dose of CBD-free hempseed oil under their tongue on two different occasions. The first time they consumed the hempseed oil, the participants were incorrectly told it contained CBD, while the second time they were informed it did not contain CBD. The researchers observed that there was no significant change in measurable stress and anxiety responses from one event to another; indeed, the participants had ingested no CBD at all. However, they found that participants who previously believed CBD was effective for reducing anxiety reported that they felt less anxious after taking the CBD-free dose of hempseed oil they believed to contain CBD.
The researchers concluded that while CBD offers a potential anti-anxiety benefit, it is important in future clinical studies to measure for the placebo effect. If participants believe that CBD alleviates anxiety, it could skew the results of future studies, especially those that rely on self-reported results. Many researchers may look to include criteria that controls for the placebo effect in future anti-anxiety cannabis studies.
5. Microwave distillation and cannabis extraction
A new method of cannabis extraction relying on the use of microwaves was developed and articulated in an article published in the Molecular Diversity Preservation International's publication in March 2021. This method yielded an extract rich in terpenes and terpenoids, which are thought to offer therapeutic benefits of their own, not unlike phytocannabinoids. However, in most conventional extraction methods, exposure to heat and air can cause significant loss of terpenes and terpenoids.
The development of a new method of microwave distillation could help extractors preserve more terpenes, not only paving the way for improved natural flavors and aromas of cannabis extracts, but also emphasizing the therapeutic benefits that terpenes could offer to consumers.
6. Terpene formulation tested against Human Coronavirus strain 229E
Researchers studied the effects of a terpene-based formulation, with and without the addition of CBD, against Human Coronavirus strain 229E. This was the first test recorded of the activity between terpenes and CBD against a coronavirus. The results of the test suggested that a terpene-formulation of beta caryophyllene, eucalyptol, and citral were effective antiviral agents, especially alongside CBD.
The positive results of the terpene-formulation in combination with CBD come at a time when the COVID-19 coronavirus pandemic is an ongoing public health crisis. While the Human Coronavirus strain 229E is distinct from COVID-19, this study gives researchers insight into how cannabinoids and terpenes could potentially be used to treat coronaviruses similar to strain 229E.
7. Cannabinoid receptors and muscle pain management
An April 2021 study published in the European Journal of Pharmacology delved into how cannabinoid receptors relate to pain management, specifically in the muscles, shed new light on the relationship between the human body's endogenous cannabinoid system (ECS) and muscular pain. The study found that CB1 receptor antagonists – compounds that reduce activity in the cannabinoid receptors found primarily in the brain – intensified muscle pain. Meanwhile, CB2 receptor antagonists – those that reduce activity in the cannabinoid receptors most closely associated with the immune system – did not alter perceived muscle pain.
The study furthers our understanding that pain management and the ECS are linked, and reinforces the notion that the CB1 receptor is likely the primary cannabinoid receptor through which pain perception is affected. Further studies into how the cannabinoid receptor influences pain and which phytocannabinoids and terpenes can elicit a desirable response for pain management outcomes are likely to appear in 2021 and beyond.
8. Cannabis consumption and attention disorders
In a March 2021 study published in the Journal of Studies on Alcohol and Drugs, researchers examined the relationship between daily cannabis consumption and ADHD symptoms. To do so, they selected 62 adults aged 19 to 25 who consume cannabis regularly and met a baseline screening for ADHD symptoms.
For the next two weeks, the participants consumed cannabis daily. The researchers observed that ADHD symptoms could be exacerbated by daily cannabis consumption – however, it was not entirely clear what caused this result.
Future studies could aim to hone in on which phytocannabinoid(s) are responsible for the exacerbation of ADHD symptoms, giving consumers living with attention disorders insight into which cannabis strains and products will work for them without worsening their symptoms.
9. The ECS - Autism Spectrum Disorder connection
Researchers examined a potential link between the ECS and Autism Spectrum Disorder in an article published in the Molecular Diversity Preservation International's publication. The research was based on the fact that previous studies showed alterations of ECS functionality in people living with Autism Spectrum Disorder, primarily observed through low blood levels of endocannabinoids produced by the body, like anandamide or 2-arachidonoylglycerol (2-AG).
The researchers pose the question "could cannabinoid treatment be efficacious" in terms of managing symptoms associated with Autism Spectrum Disorder, such as difficulties in social communication and interaction or repetitive patterns of behavior. Further studies into the link between the ECS and Autism Spectrum Disorder, and how phytocannabinoids may play a role, are to be expected in the future.
What new medical cannabis research will emerge in 2021?
These 10 studies are just a taste of what researchers are uncovering about cannabis. More groundbreaking research is happening all the time, and with very new answer uncovered there are a multitude of new areas, applications, and possibilities to explore. The headline, though, is that after a near-century of cannabis prohibition, science is finally confirming what cannabis consumers have known for millennia: cannabis is integral to health and wellness.