By Adrienne Dellwo, Medically reviewed by Jenny Sweigard, MD
February 10, 2020
The endocannabinoid system (ECS) plays important roles in your body well beyond the process it's named for, which is interacting with cannabis, also known as marijuana. Did you realize we had a whole system named after pot? We do. That's because the substances that come from the marijuana plant—cannabinoids—were discovered first.
What Is the Endocannabinoid System?
Let's look at the word "endocannabinoid." "Cannabinoid" comes from "cannabis," and "endo" is short for "endogenous," which means that it is produced naturally inside of your body. So "endocannabinoid" simply means cannabis-like substances that naturally occur inside us.
The ECS itself is made up of three parts:
- Receptors in the nervous system and around your body that endocannabinoids and cannabinoids bond with
- Enzymes that help break down endocannabinoids and cannabinoids
Not only is the ECS a natural part of our bodies, but it's also a crucial one. You may have heard a lot of claims about the medicinal properties of marijuana in general or of the cannabinoids THC and CBD. With so many seemingly unrelated effects, you might wonder whether it's just a lot of hype from people who want the drug legalized; however, medical science backs up many of these claims, and the reason for the far-reaching effects have to do with the size and scope of the endocannabinoid system itself.
The Endocannabinoid System: Crucial for Homeostasis
To understand the ECS, it first helps to understand what homeostasis is.
Basically, homeostasis is your body's efforts to keep everything in the right zone. It tries to keep your internal environment stable and optimal no matter what's going on in the environment around you. Think of all the gauges in the dashboard of a car or airplane. Those all tell the operator whether things are—or aren't—operating in the proper zone.
Just like the electronics in a car or plane, your body works continuously to monitor important levels and functions in your body. Is your temperature too high, too low, or just right? Are your hormone levels what they should be? Is your heart beating too fast? Do you need fuel or rest? Is too much of something building up in your bloodstream or inside of your cells?
When something is operating outside of the right range, your body activates the ECS to help correct it. So when you're really hot and begin to sweat, thank your ECS for working to cool you down. Stomach growling? That's your ECS helping remind you to eat because you need fuel.
The ECS does this via cannabinoid receptors found in select tissues. We have (at least) two types of cannabinoid receptors:
- CB1 which is in the central nervous system (brain and nerves of the spinal cord)
- CB2 which is in the peripheral nervous system (nerves in your extremities), the digestive system, and specialized cells in the immune system
Cannabinoid receptors are believed to be among the most plentiful in our central nervous system, and some researchers hypothesize that we could have a third, undiscovered one, as well.
Through those receptors, the ECS helps regulate a lot of important functions, such as:
- Immune function
- Inflammation, including neuroinflammation
- Motor control
- Temperature regulation
Your body activates the ECS with precision so that it impacts only what it needs to. For example, if your reproductive hormones are out of whack, it will work to regulate them without altering your digestion or immune system.
Then, once the endocannabinoids have done their job and brought things into balance, certain enzymes come along to break them down and prevent them from going too far and upsetting the balance in the opposite direction. It's a precise response.
That's different from what happens if someone smokes marijuana and floods their system with cannabinoids. Then the drug has wide-ranging impacts on physiology, some of which may be beneficial while others may be harmful.
Homeostasis is essential to our health and survival, so when the ECS isn't working properly, it can cause a lot of problems for you.
Because cannabis products can stimulate activity of the ECS, they're obvious targets for potential treatments, and a ton of research is going on around the world. We also have medications made from synthetic (lab-created) cannabinoids, such as the drug nabilone.
We're already seeing a lot of research on cannabinoid-based treatments and we're likely to see more as we gain a better understanding of the system and the substances. Changes in legal status have also driven research.
The Role of Receptors and Enzymes
When someone smokes marijuana, a cannabinoid from the plant attaches to the CB1 receptor in the brain and creates a high. This cannabinoid is called THC, which is short for delta-9-tetrahydrocannabinol. One of your own endocannabinoids that attaches to the same receptor is called anandamide.
While THC and anandamide are similar, anandamide doesn't get you high like THC. Anandamide does have a calming effect, though. In fact, it gets its name from ananda, the Sanskrit word for bliss.
The reason anandamide doesn't get us high and THC does lies with something called the FAAH enzyme. FAAH's job is to break down anandamide and other endocannabinoids. It works quickly on the ones your body creates, but it can't break down THC. That means THC sticks around for a lot longer and therefore has a much greater effect.
In the brain, cannabinoids, and endocannabinoids work as neurotransmitters (chemical messengers that deliver information from one cell to the next.) Neurotransmitters all interact with a lot of different receptors and thus have a lot of different effects.
A plant-based cannabinoid that's gotten a lot of attention from researchers is cannabidiol or CBD. It doesn't have any psychoactive properties, so its benefits come without the high of THC. One known function of CBD in the brain is to stop the FAAH enzyme from breaking down anandamide, so the anandamide can have more of an impact. That's believed to be why CBD can help treat anxiety disorders.
As medical science has learned more about the ECS, it's also discovered several conditions that appear to be related to dysregulation of the system, which is called clinical endocannabinoid deficiency (CECD). CECD isn't a disease itself but is an umbrella term encompassing conditions with this common feature.
Conditions for which there is evidence that CECD may play a role include:
- Irritable bowel syndrome
These conditions are sometimes called "functional conditions" or "central sensitivity syndromes." They tend to be resistant to most treatments, so researchers are looking into cannabis-based treatments.
These conditions also generally involve more than one system—which makes sense when you look at the areas influenced by the ECS.
For example, fibromyalgia involves the central and peripheral nervous systems, the immune system, the endocrine (hormonal) system, and even the digestive system. It's also been linked to premature perimenopause, problems with conception, and early hysterectomy. Temperature sensitivity and poor memory are common symptoms.
That seems like a grab-bag of unrelated problems until you think about homeostasis and the ECS.
We're still early in the process of figuring out how to correct endocannabinoid deficiency, but the increasing availability of medical marijuana and CBD products has been largely embraced by the patient community and we're likely to see a lot more research in that area.
Cannabinoids are being researched as potential treatments for all kinds of conditions, not just those involving endocannabinoid deficiency.
Some of the illness they're being researched for include:
- Alzheimer's disease
- Cardiovascular disease
- Neurological, neurodegenerative, neurodevelopmental, and psychiatric illnesses
- Acute and chronic kidney disease
- Autoimmune diseases
- Chronic inflammatory diseases
- Chronic pain conditions
CBD already is in use for pediatric epilepsy, pain, inflammation, acne, asthma, and a host of other conditions.
A Word From Verywell
Certainly, cannabinoids such as marijuana and CBD oil appear to hold a lot of promise as treatments for a wide range of ailments. However, keep in mind that any treatment—even natural ones—can cause unwanted side effects. Self-treatment can be dangerous at put your health at risk, so be sure to include your doctor in your decisions.
The legality of marijuana varies from state to state, so to protect yourself, be sure you know the laws where you live. A 2018 Farm Bill, passed by Congress in December 2018, is expected to be signed into law soon. It will legalize hemp products--but not marijuana--at the federal level. Still, it pays to know local laws on CBD as well. The website ProCon.org has information about which states have laws specific to CBD oil. A site called Governing maintains a map of where marijuana is legal in some form.
The good news is that making hemp products legal not only opens up treatment options for a lot of people, it could speed up medical research on CBD as well as eventually drive down prices.