Top Cannabis Research Breakthroughs of 2020
Despite the pandemic disrupting daily life for over a year, researchers have continued to study cannabis and its effects on the human body. Here are some of the most important discoveries made by scientists in 2020.
Endocannabinoid System
The endocannabinoid system was only discovered in the 1990s, and many of its processes remain a mystery. The system’s two main receptors, CB1 and CB2, are similar but function very differently, making it difficult to develop medications that selectively activate just one. Scientists are searching for ways to target the CB2 receptor without activating CB1, which could reduce inflammation without causing a high. This is especially important for treating neurodegenerative disorders and pain, allowing patients to remain clear-headed.
To achieve this, drug developers need to know what both receptors look like in their resting and activated states. However, this is challenging because the receptors are extremely small. In 2020, scientists succeeded in capturing images of CB1 and CB2 receptors in various activation states using electron microscopy, a technique that involves firing electrons at the receptors and measuring their deflections. This is a significant step forward that could help in developing targeted medications leveraging the power of the endocannabinoid system.
CB1 and CB2 receptors also play a key role in the positive effects of cannabis. According to a study published at the end of 2020, CB1 receptors are responsible for the pleasurable sensations from low doses of THC, but high doses become unpleasant due to CB2 activation. CB2 activation reduces dopamine, which typically drives the desire to repeat euphoric experiences, counteracting the dopamine effects of CB1 activation. The study concludes that our enjoyment and desire for cannabis are determined by a tug-of-war between CB1 and CB2 receptors: if CB1 is more active, you’re more likely to seek the effect again.
Cannabis for Chronic Pain Treatment
Even in countries with medical legalization, many doctors hesitate to prescribe cannabis due to a lack of “sufficiently good” research. The gold standard is double-blind, placebo-controlled clinical trials, which are still relatively rare. Two such studies confirming the pain-relieving properties of cannabis for chronic pain were conducted in 2020.
The first study found that a THC to CBD oil ratio of 48:1, administered sublingually, significantly improved the quality of life for women suffering from fibromyalgia, a chronic pain condition that is difficult to treat. Patients consumed an average of 4.4 mg of THC per day and reported their pain was halved, their productivity increased, and their mood improved compared to those who received a placebo.
The second study tested the use of THC for patients with chronic neuropathic pain. Patients inhaled THC via a vaporizer. A small dose of just 1 mg THC was enough to reduce pain compared to placebo, and the effects lasted for more than two hours.
Together, these studies confirm the benefits of THC in treating chronic pain symptoms. Importantly, these benefits were achieved with low or moderate doses of THC.
THC and Motivation
Many athletes use cannabis to enhance performance, enjoy their workouts, and recover after training, challenging the old stereotype that cannabis makes people lazy and inactive. It’s known that CB1 receptors—the main targets for THC—play a key role in motivation, but exactly how THC use affects performance is still unclear.
To clarify, French scientists conducted experiments with mice. They trained the rodents to unlock a running wheel and found that THC did not affect the mice’s willingness to run or their performance during running. These results suggest that THC does not impact motivation for physical activity, debunking the belief that cannabis use causes laziness.
However, the researchers found that genetically removing CB1 receptors in mice did reduce their tendency to run. This is important because excessive THC use can cause tolerance, which people perceive as a weakening of THC’s effects, and is associated with a reduction in CB1 receptors. This suggests that motivation may decrease with frequent use of THC-rich cannabis.
Cannabinoids and Parkinson’s Disease
Over the past decade, scientists have studied the role of CBD and THC in slowing the progression of age-related brain diseases like Alzheimer’s. Recently, they began investigating the effects of CBD and THC on Parkinson’s disease symptoms and found that cannabinoids may help relieve some of them.
One of the main symptoms of Parkinson’s is tremor, which can worsen during stress. It’s believed that CBD’s anxiety- and stress-reducing effects may help lessen tremors. To test this, Brazilian scientists conducted a double-blind, placebo-controlled trial with Parkinson’s patients. They simulated public speaking situations, giving participants either a placebo or CBD oil. The researchers found that a single 300 mg dose of CBD reduced both anxiety and tremor compared to placebo. This suggests that CBD may be useful for reducing tremors in Parkinson’s patients during stressful situations.
Other common symptoms of Parkinson’s include slowed movement and rigidity. These are usually treated with medications that can have unwanted side effects, such as dyskinesia (involuntary movements in one or more muscle groups).
Interestingly, there are several ways to help block these involuntary movements, such as blocking CB1 receptors and activating CB2 receptors. Fortunately, THCV (tetrahydrocannabivarin), one of the many cannabinoids produced by the cannabis plant, fits the pharmacological profile needed to reduce dyskinesia. Spanish scientists tested THCV on mice and found that it delayed the onset of medication-induced dyskinesia and reduced the intensity of involuntary movements. These results highlight the potential of cannabinoids in treating Parkinson’s disease.
A New Cannabinoid
Cannabis contains over a hundred beneficial cannabinoids, each affecting people differently. More than 150 cannabinoids have been identified, and scientists continue to discover new ones.
Italian researchers isolated a new cannabinoid, THCP (tetrahydrocannabiphorol), and tested its ability to bind to endocannabinoid receptors and affect mouse behavior. THCP demonstrated the traditional effects caused by THC, but even more strongly. The new cannabinoid bound to CB1 and CB2 receptors in the endocannabinoid system similarly to THC. These connections were strong enough to reduce pain and induce euphoria.
The researchers concluded that THCP binds to CB1 receptors about 30 times more easily and to CB2 receptors about 6 times more easily than THC. This doesn’t necessarily mean THCP will have a stronger effect than THC, but it may be responsible for the intense psychoactive effects of some cannabis strains.