Since the 1990s, scientists have been discovering and mapping out the role of the endocannabinoid system (ECS). This exciting field of research is still young, but the early results may help explain how the endocannabinoid system and cannabidiol (CBD) interact to provide pain relief and modulate the immune system. What exactly is the endocannabinoid system, and how does CBD affect it and our bodies? Check out this ECS 101 primer to learn the answers and improve your understanding of how your body works.

What is the Endocannabinoid System?

The ECS is a system comprising your body’s own cannabinoids, the receptors to which they bind, and the enzymes that metabolize them and break them down after their job is done. Yes, you read that right: Your body produces its own cannabinoids, similar to those found in cannabis. The job of the endocannabinoid system, as scientists currently understand it, is to help your body maintain homeostasis—that is, to maintain a consistent internal cellular environment regardless of changing conditions. It does this by releasing endocannabinoids in response to a wide range of stimuli, including pain, inflammation, hunger, and stress.

Bradley Alger, Ph.D., whose research has focused on endocannabinoids for the past two decades, refers to the ECS as “the bridge between body and mind.”  He notes that ECS receptors are found in the brain, immune cells, connective tissues, and nearly all organs—virtually throughout the entire body. The fact that the endocannabinoid system interacts with so many different systems in your body may hold the key to understanding why cannabis, and particularly CBD, seems to be helpful in so many different disorders.

When Was the Endocannabinoid System Discovered?

As with most things scientific, scientists discovered the ECS piece-by-piece over time, with each new discovery building on previous knowledge. It’s difficult to credit any particular person with the discovery of the endocannabinoid system, but the following key events helped build our understanding.

In the 1960s, Raphael Mechoulam, an Israeli researcher, was surprised to learn that no one had yet isolated the psychoactive ingredients in cannabis. He led the team that helped isolate THC, as well as other active constituents of the plant. That discovery led other scientists to research the method of action—figuring out precisely how THC produces its effects in humans.

In 1988, Allyn Howlett and William Devane used a rat model to demonstrate the existence of a cannabinoid receptor in the brain. Two years later, Miles Herkenham mapped out the location of a cannabinoid receptor system in several mammals, including humans. By the mid-1990s, Mechoulam and others had identified and isolated two endocannabinoids:  anandamide and 2-arachidonoylglycerol.

These discoveries opened the door to a rapidly evolving field of research, which may have far-reaching effects on the role of the endocannabinoid system and CBD in treating disease and promoting general wellness.

The Parts of the Endocannabinoid System

The ECS consists of three key parts:

• Endocannabinoids are molecules produced by your body in response to various stimuli which bind to endocannabinoid receptors.
• Endocannabinoid receptors sit on the surface of your cells, waiting for messages in the form of endocannabinoids.
• Metabolic enzymes break down and dispose of the endocannabinoids after they’ve been used.

Currently, scientists know of two kinds of endocannabinoid receptors, commonly referred to as CB1 and CB2. They differ structurally, as well as in their distribution throughout your body.

CB1 receptors are found throughout the body, including the central and peripheral nervous system as well as the heart, reproductive organs, and the hypothalamus. They are thought to be related to appetite, pain and sensory perception, metabolism and the reward centers of the brain.

CB2 receptors are found in immune cells in various parts of the body, where they appear to regulate the release of cytokine and the migration of immune cells.

What Cannabinoids Do

Endocannabinoid receptors are known to interact with three different types of cannabinoids: endocannabinoids, such as anandamide and 2-AG (2-arachidonoylglycerol), which are produced by our own bodies; synthetic cannabinoids, which are synthetically produced; and phytocannabinoids, which are found in cannabis and hemp, among others. You can think of cannabinoids as a sort of key. When one of them binds to a receptor, it “unlocks” the cell’s response to a change in the environment around it.

Take, for example, inflammation—one of the body’s common responses to injury or infection. When the body senses something that can damage tissue, the surrounding cells signal for a release of cytokines, which call immune cells (leukocytes) to the site to fight off the damage. Ideally, once the damage is controlled, the leukocytes should disperse and the inflammation should go away. All of this is controlled by the ECS through the transmission of cannabinoids between cells.

But what happens when the endocannabinoid system malfunctions? Recent research suggests that many inflammatory conditions, including osteoarthritis, brain inflammation and colitis respond well to therapies that increase cannabinoid receptors or otherwise stimulate the ECS.

The Endocannabinoid System and CBD

Much of the research on the ECS over the past 25 years has been sparked by the number of seemingly unrelated conditions and symptoms that appear to be helped by cannabis and CBD. The discovery of a system that functions as a “master regulator” of the body’s other systems, and which is in turn affected by cannabinoids, has opened many avenues of research into new treatments for such wide-ranging disorders as cancer, autoimmune disorders such as ALS, depression and obesity.

As scientists build their understanding of how the endocannabinoid system works, they are increasingly considering not only new therapies and treatments but entirely new ways of approaching health and wellness. As one recent study concluded, research into the endocannabinoid system over the past three decades has led to “fruitful studies” that have “unraveled the complexity of the endocannabinoid system.” There’s still much to learn, but understanding how the endocannabinoid system functions may lead us to an entirely new understanding of health.