The ‘Glaring Omission’ of the Endocannabinoid System From Mainstream Medical Knowledge, And its Real World Impact

Despite being one of the most important regulatory systems in human physiology, the endocannabinoid system (ECS) remains inexplicably absent from almost all mainstream medical education.

A report published by Volteface in 2022 found that in the UK, while around 40,000 clinicians are eligible to prescribe medical cannabis, only 100 are thought to do so actively.

As is often discussed in the industry across the world, this is due to a critical lack of understanding about cannabis-based medicines amongst doctors.

However, according to Dr Stefan Broselid, molecular pharmacologist and founder ECS Education, this lack of understanding goes far beyond cannabis as a medicine, meaning a crucial physiological system is scarcely acknowledged in mainstream medical knowledge.

He told Business of Cannabis: “Essentially, we need to present the endocannabinoid system (ECS) in a comprehensive, physiological context, because this is fundamentally about human biology.

“It actually has very little to do with medical cannabis. The connection between the two came about by chance; it was through studying cannabis that we discovered the ECS. But the system itself is foundational to human physiology.”

Glaring omission

Over the last decade, Dr Broselid has read ‘thousands and thousands of papers’ on the ECS. He believes this has given him a rare, comprehensive overview of the system, an overview that most healthcare professionals, through no fault of their own, simply do not have.

“The main issue with the launch of medical cannabis as a therapeutic was that healthcare professionals were not allowed to get a core understanding of the ECS prior to that.”

According to Dr Broselid, the lack of education has led to widespread misconceptions and a missed opportunity to integrate ECS knowledge into clinical practice.

“Stigma has spilt over from cannabis,” he says. “And I think it’s got to do a lot with semantics.”

In a revealing study published in October 2024, which surveyed 610 nurses and nursing students in Portugal, 79.6% of nurses and 84.3% of students appreciated the therapeutic benefits of medical cannabis, but 71.7% of nurses and 79.5% of students had never heard of the ECS.

He suggests, that this is ‘perhaps because we named one of the most important physiological systems in our bodies after one of the most controverial plants in society’.

One of the most striking observations Dr Broselid has made is how slowly ECS knowledge has been adopted in educational materials.

To demonstrate this lack of adoption visually, Dr Broselid refers to an article from his education platform ECS.education, examining one of the most utilised and widely cited textbooks in medical education, the ‘Guyton and Hall Textbook of Medical Physiology’.

He explained: “I attempted to illustrate the delay between scientific discoveries and their inclusion in medical literature. What’s striking is how long it’s taken for the ECS to be recognised, especially compared to other major discoveries.”

This omission has persisted for over 30 years, even in the most recent 2020 edition, despite the ECS playing a crucial role in regulating various bodily functions, including mood, appetite, pain perception, and immune response.

‘Expanding mountain of evidence’

In debates around the world regarding the continued reluctance to integrate medical cannabis treatment into mainstream systems, such as the NHS, the lack of research on the efficacy and safety of the drug has become an all too familiar, now almost automatic response from the medical community.

Although, as previously stipulated by Dr Broselid, medical cannabis treatment addresses only a fraction of the endocannabinoid system’s broader role, this reasoning falls short when examining the lack of adoption wider education around the ECS.

Dr Broselid demonstrates that extensive research has been carried out on the ECS, but the exclusion from medical education persists, leaving a glaring chasm of understanding for medical professionals.

“The ECS plays a regulatory role in virtually every major system in the body, whether it’s the endocrine, nervous, muscular, or any of the 12 to 13 primary physiological systems. It’s central to maintaining homeostasis.

“So if medical professionals aren’t being taught about the ECS in medical school, and currently, they’re not, they’re missing a crucial part of how the human body works. Without that knowledge, how can we expect them to deliver truly optimal care? It’s simply not possible.”

A separate study conducted by ECS.education, which examined data from 1000 academic articles published between 2002 and 2022, found that over 1200 publications in PubMed had ‘Endocannabinoid System’ in their titles, and 76,843 total citations were made based on Google Scholar data.

Furthermore, it found that ECS’ ‘h-index’ a metric commonly used in academic research to measure the productivity and impact of a researcher, journal, or specific field of study based on citations, was 138, putting it well above research on more well-established systems including the digestive, endocrine, respiratory and lymphatic systems.

“Yet despite this growing body of knowledge, almost none of it is being translated into medical education. That’s the real issue. We have this expanding mountain of evidence, but it remains disconnected from the training that healthcare professionals receive. It’s incredibly frustrating.”

Real-world consequences

Far beyond the various indications medical cannabis treatment has been proven to help treat, understanding the ECS could have major implications for the treatment of many common modern health issues.

“I feel the industry is still very focused on medical cannabis, which makes sense, as it’s currently the primary therapy we have that directly targets the endocannabinoid system (ECS). However, in my view, the ECS is deeply interconnected with nutrition,” Dr Broselid continued.

As the ECS is a ‘lipid-based signalling system, meaning the molecules it uses to function are derived from dietary fats like omega-6 fatty acids, which serve as the precursors to endocannabinoids, he believes modern diets are driving an imbalance in this system.

“In today’s diet, where many people consume 20 to 30 times more omega-6 than omega-3 fats, this imbalance can lead to overactivation of the ECS. I believe this chronic overstimulation is a key driver behind the rise of metabolic syndrome and obesity that we’re seeing globally.”

In efforts to address this knowledge gap, Dr Broselid is working with the Medical Cannabis Clinicians Society (MCCS) in the UK to develop a ‘range of training programmes’ for health professionals.

“My role focuses specifically on the endocannabinoid system (ECS). I’ve created a 40–45 minute course on ECS physiology, which covers the system in detail but includes very little about cannabis itself.

“The emphasis is on understanding ECS imbalance in various disease states and how it relates to broader human physiology. This course is set to be delivered to all MCCS members during the upcoming spring.”

This article was originally published by Business of Cannabis and is reprinted here with permission.