One of the most exciting things about the cannabis plant is the way that it interacts with our body's internal systems. It turns out that as we learn more about the cannabinoids produced by the cannabis plant (phytocannabinoids), we also learn more about our own bodily makeup, the cannabinoids that we create ourselves (endocannabinoids), and their functions.
What is the endocannabinoid system?
Each of us comes with an endocannabinoid system (ECS system), which does much more than govern the way we experience the intoxicating or psychoactive properties of cannabis. The role of the endocannabinoid system is to keep our bodies regulated, helping us to maintain balance, or homeostasis. When we achieve internal homeostasis, we're at peak performance, in contrast to when the body has an endocannabinoid system deficiency.
What does the endocannabinoid system do?
Because of the need for inner balance, the endocannabinoid system functions to maintain homeostasis in fish, reptiles, birds, and mammals, including humans. Pain, stress, appetite, energy, cardiovascular function, reward perception, reproduction, and sleep are only a few of the processes in which the ECS is involved.
What are endocannabinoids?
The human endocannabinoid system is made up of three main components: cannabinoid receptors, endocannabinoids, and the enzymes that break them down. This system is present throughout the entire body — it's on immune cells in our bloodstream, all over our nervous systems, on the entire axis of the spinal cord, and in virtually every cell in the brain. There are even cannabinoid receptors in our skin.
How was the endocannabinoid system discovered?
The body naturally produces endocannabinoids, the two most prevalent being: anandamide and 2-arachidonoylglycerol (2-AG). Anandamide was discovered in the 1990s, so there is still much research to be done in order to fully understand it, but a good way to associate anandamide is that its root was taken from the Sanskrit word “ananda,” meaning eternal bliss or happiness.
Anandamide and 2-AG are made on demand and seek out the cannabinoid receptors CB1 and CB2. CB1 receptors affect motor and cognitive function, whereas CB2 receptors play a more critical role in neuroprotection and neuroinflammation. Though these two receptors have been the most studied by scientists, there are others that cannabinoids can also bind to, like TRPV proteins, which are responsible for the body's sensations of temperature. For instance, the flush experienced when eating chili peppers is a TRPV response.
Although the CB and TRPV receptors are the major players in the ECS, there are at least three other receptors that may eventually be considered cannabinoid receptors, once their functions are fully understood: GPR55, GPR18, and GPR119.
CB1 receptors can be found largely in the central nervous system, where they regulate a wide variety of brain functions. In fact, they're the most widely expressed protein of their kind in the brain. There, the receptors regulate the release of other neurotransmitters, such as serotonin, dopamine, and glutamate.
Think of the neurotransmitters as children at a crosswalk after school: The ECS acts as a crossing guard, allowing them to cross in tightly controlled intervals and numbers.
CB2 receptors are mostly found on immune cells, which circulate throughout the body and brain via the bloodstream. These receptors are also found on neurons in a few select brain regions and are involved in pain relief, inflammation reduction, and neuroprotection.
How Does CBD Help the Endocannabinoid System?
Because our bodies already use “in-house” endocannabinoids to regulate many functions, we come with lots of target sites where phytocannabinoids can also activate. Beyond the aforementioned known and potential cannabinoid receptors, phytocannabinoids bind to many other targets. For instance, cannabidiol (CBD) has at least 12 sites of action in the brain.
The genes that encode the CB1 and CB2 receptors are CNR1 and CNR2. These genes are of particular interest to scientists, as when mutated they can lead to different responses to the body's endogenous cannabinoids, which can in turn influence health and disease states.
Some alterations of CNR1 have been linked to obesity and psychiatric disorders such as schizophrenia, depression, anxiety, and drug and alcohol addiction. It is thought that further study into these genetic variants could lead to the prevention and treatment of several diseases that are based on a dysfunction of the ECS. Much more research is needed in order to fully understand the role of ECS in health, and how genetic variability in this system contributes to disease.
Though there is much common ground between our ECSs, everybody's is unique: the rates of anandamide and 2-AG production and break down can vary wildly, as can the levels of cannabinoid receptors in our bodies.
For instance, prolonged, daily use of cannabis causes the brain to reduce the number of CB1 receptors that are available for activation, however, using human brain imaging, we see that after only 48 hours of abstinence from cannabis, the ECS is reinstated and the level of CB1 receptors goes back to a comparable level of a non-cannabis user.
ECS knowledge helps us to understand more about ourselves and the way that we were seemingly built to partake in cannabis and its phytocannabinoids. Maintaining homeostasis becomes a dance between plant and being — one that calls for much more scientific research, but that in the meantime brings us great ananda.
Major contributions from Dr. Adie Rae.