Cannabinoids are able to take effect by interacting with our endocannabinoid system. But what happens when the body doesn’t produce enough endogenous cannabinoids? Cannabis researcher Dr. Ethan Russo suggests that this may be the root cause of a family of common diseases and disorders.
Defining Endocannabinoid Deficiency
First explored in 2004, the theory for a clinical endocannabinoid deficiency (CED) was born from the idea that neurotransmitter deficiencies are associated with brain disorders such as acetylcholine in Alzheimer’s disease and dopamine in Parkinson’s disease. A similar deficiency in endocannabinoid levels may lead to a neurological disorder.
Everyone has a certain endocannabinoid baseline. This corresponds to the circulating levels of the primary endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG) but also includes the rate of their synthesis and breakdown as well as the relative density of cannabinoid receptors in the brain.
Because the endocannabinoid system acts as a nearly universal regulator for a wide array of physiological systems, a decrease in endocannabinoid function could be far reaching. Symptoms of an endocannabinoid deficiency may include a lowered pain threshold and improper regulation of digestion, mood, and sleep. Such a deficiency could be caused by a combination of genetic and environmental factors.
A Common Cause for a Family of Disorders
According to Dr. Russo and the CED hypothesis, the most evidence for CED exists for migraine headaches, fibromyalgia, and irritable bowel syndrome (IBS). These disorders share several commonalities:
- An increased sensitivity to pain
- Clinical diagnosis based on subjective criteria as opposed to objective medical imaging, tissue pathology, or blood tests
- Comorbidity—many patients may only suffer from one of these disorders but lifetime risk to develop a second or all three is common
- And association with increased incidence of anxiety and depression
IBS, for example, is the most commonly diagnosed gastroenterology disorder in the United States and affects between 10-15% of the Western world’s population. Medical researchers believe IBS may be triggered by gastrointestinal stressors such food poisoning or heavy antibiotic administration in genetically predisposed individuals. However, its exact causes are still unknown. Some researchers have theorized that IBS and other functional bowel disorders may arise from an exaggerated sensitivity to pain as a result of distorted signaling and processing between the gut and the brain.
The endocannabinoid system is responsible for modulating GI propulsion, secretion, and inflammation in the gut. One study found that a genetic variation affecting endocannabinoid metabolism was present in diarrhea-predominant IBS patients. This gene variant was significantly associated with colonic transit time in IBS with diarrhea. As far as a potential mechanism, another study found that the endocannabinoid AEA colocalized with receptors in the colon that control the contractile force of gut muscle fibers in healthy patients.
While more clinical evidence is needed, other disorders have also emerged as potential endocannabinoid deficiencies including PTSD. And it’s now becoming clear that endocannabinoid care represents an important part of a healthy lifestyle.