How Does Cannabis Work in the Body?
The Endocannabinoid System - What is it?
The first thing to note about how cannabis works in the body is to understand the Endocannabinoid System. The Endocannabinoid System is a network of receptors throughout the body that cannabinoids can bind to, causing a chemical reaction to occur, resulting in a change or message in the body. The identification of the Endocannabinoid System prompted the research for cannabinoid compounds that exist inside the body that bind to these receptor sites. This led to the discovery of N-arachidonoylethanolamine (AEA, anandamide) and 2-arachidonolglycerol (2-AG) - two cannabinoids that exist inside of the body. These are called endocannabinoids and since their discovery, other endocannabinoids have been discovered. These endocannabinoids work as a specific key to bind to a receptor site and trigger the cell to send (or stop sending) a message. The goal of this system is to correct imbalances in the body and maintain homeostasis.
The Endocannabinoid System - What Systems are Involved?
As you can see from this diagram, the Endocannabinoid System is present throughout the body. These sites have Endocannabinoid receptors that are of a particular shape so only a specific compound can fit in that space (think lock and key). Once the compound binds to that site, the receptor is either activated (agonized) or reduced (antagonized). Cannabinoids such as THC work because they can bind to these receptor sites, leading to the activation of the deactivation of the receptor. More on that to come.
There are two main types of receptor sites to focus on - CB1 and CB2.
CB1 receptors are mainly located in the brain and spinal cord. CB1 receptors are essential for a healthy functioning brain and are one of the most common receptors in the entire nervous system. Depending on what region of the brain they are located in, they can be moderators of your memory, mood, motor function, or your perception of pain. The location on cells that involve pain perception may explain why many users experience pain relief with cannabis use. Some users also report improved reading and productivity with cannabis use, this could be due to the abundance of CB1 receptors in the hippocampus (part of the brain responsible for memory). This effect does not occur for all users.
CB2 receptors are located on immune cells as well as in the peripheral nervous system and the skeletal system.
CB1 and CB2 receptors are located in the heart, liver, gastrointestinal system, pancreas, reproductive system, and in skin.
It's important to note that different phytocannabinoids (THC, CBD, CBG, etc) can act on the CB1 and CB2 receptors to agonize (bind and increases receptor activity), antagonize (binds to a receptor but elicits no response) or work as an inverse agonist (binds to a receptor and reduces receptor activity). So how does this all come together? The body produces its own cannabinoids to bind to these receptors, but we can also use cannabinoids from plants to bind to these receptors - causing a desired effect in the body. THC binds directly on the cannabinoid receptor
- causing receptor activation. CBD works in a few different ways, but one of the ways is to bind to a different site on the side of the receptor, affecting how other cannabinoids bind to that same receptor, causing a reaction. Cannabinoids are also able to block receptors.
Medicinal Effects of THC
Medicinal Effects of CBD
-Anticancer
-Anti-inflammatory
-Antioxidant
-Sedation/Sleep
-Neuroprotectant
-Anxiety Reduction
-Depression Reduction
-Reduction in Nausea/Vomiting
-Reduction in Intraocular Pressure
-Muscle Spasm Reduction
-Reduction in Chronic Pain
-Appetite Stimulation
-Anticancer
-Antibacterial
-Anticonvulsant
-Anti-inflammatory
-Antioxidant
-Antipsychotic
-Neuroprotectant
-Anxiety Reduction
-Depression Reduction
-Reduction in Nausea/Vomiting
-Reduction in Intraocular Pressure
-Muscle Spasm Reduction
-Reduction in Chronic Pain
-Appetite Stimulation
(Goldstein, B. (2020). Cannabis is medicine: How medical cannabis and CBD are healing everything from anxiety to chronic pain. New York: Little, Brown Spark.)