What Is the Endocannabinoid System and What Does It Do?

Author: Tim Shu, DVM

The endocannabinoid system (or ECS for short). It’s a mouthful – I know. But if we break it down it makes a lot more sense. “Endo” means within the body, and cannabinoid refers to groups of molecules like the ones found in the cannabis plant, such as CBD and THC. At this point you might be wondering, does this system interact with those plant cannabinoids? Yes, and it also creates its own cannabinoids! In order to function normally our body has to produce cannabinoids similar to what are found in the cannabis plant. 

This system is a major body system, alongside other body systems such as the cardiovascular system, the nervous system, and the digestive system, to name a few. While the other body systems have been known about for quite some time and were discovered a while ago, the endocannabinoid system is unique in that it was only recently discovered, and we know far less about it compared to the other systems.

All vertebrae animals have an endocannabinoid system, and many invertebrates do as well. This means mammals (such as humans, dogs, cats, horses, and rabbits), birds, fish, reptiles, and amphibians all have the potential to benefit from cannabinoid therapeutics.

Since the mid 1900’s, scientists have known that cannabinoids in cannabis are responsible for many of the effects of the plant. However, what they didn’t know was why cannabinoids like THC caused a “high”.

Components

The breakthrough happened in 1988, when a cell receptor was found which THC binds to. This receptor was named CB1, and at that point the story of the endocannabinoid system began to unfold, along with a new chapter in the understanding of our biology. 

Shortly afterwards in 1992, anandamide was discovered. This represented another breakthrough in our understanding of the endocannabinoid system as it was the first endocannabinoid discovered, meaning a cannabinoid produced by our own bodies. Over the next few years, another cannabinoid receptor, CB2, was discovered, and another endocannabinoid, 2-AG, was also found. 

Additionally, the enzymes that make and break down endocannabinoids were discovered. These breakthroughs gave us a better understanding of the three components that make up the endocannabinoid system: receptors, endocannabinoids, and their associated enzymes.

Function

Initially, the endocannabinoid system was thought to only be located in certain parts of the body. CB1 receptors were found in the central nervous system, and CB2 receptors were found in immune cells. But as scientists investigate further, just about everywhere they look, they find the endocannabinoid system present, from the digestive tract, to skin, muscles, and organs. We now know the endocannabinoid system exists throughout the body. But what does it do?

The primary function of the endocannabinoid system is to maintain a balanced state in the body. This is known as homeostasis. Simply put, it prevents there from being too much or too little of something. It helps keep things in a state of “just right”, and it does this for a wide range of functions, including sleep, pain, mood, memory, metabolism, inflammation, and even reproduction.

Implications

Because the endocannabinoid system is involved in so many different functions, there’s a lot of potential for medical benefits or modification of disease processes through interaction with the endocannabinoid system. For example, it’s been shown that activation of CB1 receptors results in decreased pain, and pain relief is one of the most commonly reported uses of cannabis in humans, and increasingly in animals. 

Studies performed in lab animals, human patients, and animal patients, have shown cannabinoids like CBD and THC have a broad range of potential therapeutic benefits, such as analgesic, anti-inflammatory, antiemetic, antispasmodic, antiepileptic, and neuroprotective effects.

An increased understanding of the endocannabinoid system and cannabinoids has led to a new, rapidly-growing category of medicine, known as cannabinoid therapeutics. While primarily focused on plant-based cannabinoids, this category can also encompass other compounds that interact with the endocannabinoid system to produce therapeutic results, such as decreasing the rate of reuptake or breakdown of endocannabinoids like anandamide.

The endocannabinoid system is a relatively new discovery, and arguably one of the most fascinating medical discoveries within our lifetime because of the therapeutic implications. Knowledge surrounding the endocannabinoid system and cannabinoid therapeutics is growing at a rapid pace, and we’re learning more about how cannabinoids and interaction with the endocannabinoid system can be used to improve health. 

Although a lot more remains to be discovered, one thing is for sure: our current understanding represents the tip of a very large iceberg, and the more we learn about this fascinating system, the more lives, both human and animal, can be improved through cannabinoid therapeutics.