Understanding the endocannabinoid system

By Dawn Goodman

Only since the 1960s has endocannabinoid research expanded and started to uncover cannabis’ role in health and disease. However, the analgesic and healing properties of cannabis have been recognized for many years—in the 1800s doctors in Ireland and the U.S. prescribed it regularly for pain, even to nursing mothers.

Cannabis has been cultivated by humans because of its versatile uses as industrial textile fiber, a narcotic and psychoactive agent. The plant has two identified subspecies: Cannabis indica and Cannabis sativa, although studies show there is debate among scientists about the current usage of these terms. Today the plant is mainly cultivated by humans, so crossover is common. Selective breeding to make its effects more potent has altered the original plant.

How cannabis interacts with the human body

In 1964 THC (delta-9-tetrahydrocannabinol) was identified as marijuana’s psychoactive ingredient, and is a natural compound of the cannabis plant produced mainly in the leaves and flower buds.  

Decades of research on THC led to the discovery, and mapping, of cannabinoid receptors in the human brain in 1990. The CB1 receptor is primarily located in the central nervous system, and the CB2  receptor affects the immune system (gastrointestinal tract, immune cells, etc.). These receptors translate signals from cannabinoids, chemical compounds found naturally in the body through the plants we consume (phytocannabinoids) or those existing in our body (endocannabinoids).

The combination of endocannabinoids and cannabinoid receptors form the endocannabinoid system (ECS), an internal neurotransmitter system which receives and translates these molecular messages throughout our brain, organs, connective tissue, glands and immune cells, as recorded in a 2006 review published in the British Journal of Pharmacology. Through the endocannabinoid system, these messages help regulate functions such as mood, appetite, sleep, memory, immunity, gut health and pain.

The cannabis plant’s molecules fit neatly into our endocannabinoid receptors, tapping into this vast internal healing mechanism and thus, acting on a myriad of psychological, emotional and physical ailments. Researchers are still uncovering the varied functions of this complex endocannabinoid system.

Benefits of cannabis

THC binds to the CB1 receptor located in the brain, which controls coordination, movement, mood, cognition, and memory. This is why THC can alter consciousness and produce a “high” effect. THC  activates the brain’s reward system, producing pleasure chemicals such as dopamine. But there are also non-psychoactive cannabinoids, such as the compound cannabidiol (CBD), which positively affects the ECS, and is used in various forms, including CBD oil and capsules, to treat a range of symptoms, including chronic pain from multiple sclerosis and other inflammatory and neurodegenerative disorders. According to studies published in The Journal of Epilepsy Research, it has also been found useful in treating epilepsy, especially in children.

At least 70 phytocannabinoids have been identified in the cannabis plant. These have a variety of antifungal, antibiotic and anti-inflammatory properties. Today, medical marijuana is becoming legalized throughout the U.S. to treat ailments from migraines to nausea. According to a 2018 article published in Neuropsychopharmacology, it has even been found to be productive in treating opioid addiction by reducing the effects of withdrawal from opioid dependence. There have been many studies, such as this 2016 study published in the Journal of Pain, that suggest using cannabis for chronic pain decreases the use of opioids.

Not just cannabis, endocannabinoid research expanded

As research has increased our understanding of the endocannabinoid system, the discovery of plant cannabimimetics (compounds that mimic the effects of cannabis) whose components positively affect health have been identified. Some of these are common in our medicine cabinets as well as our spice racks, including echinacea, (also known as coneflower), black pepper (Piper nigrum), rosemary (Rosmarinus officinalis) and chocolate (Theobroma cacao L). Other plants containing cannabimimetics and phytocannabinoids are more exotic, like kava (Piper methysticum) and maca (Lepidium meyenii).

The list is extensive. Pharmaceutical companies are producing synthetic cannabimimetics such as Sativex® by GW Pharmaceuticals, a cannabis-based medicine that contains both THC and CBD and is believed to relieve neuropathic pain in adults with multiple sclerosis, according to a 2006 article published in the British Journal of Pharmacology. Research on cannabis and cannabimimetics has become one of the fastest growing fields in psychopharmacology.