Cannabinoids show preclinical promise for inflammatory bowel disease and colorectal cancer but clinical evidence is lacking | Research

The takeaway

A review found that while cannabinoids show anti-inflammatory and anti-tumor effects in lab and animal models relevant to IBD and colorectal cancer, clinical evidence for these specific conditions is limited to questionnaires and small pilot studies.

Read this if you have inflammatory bowel disease or are interested in whether cannabinoids could treat gut inflammation or colorectal cancer.

No approved cannabinoids for IBD; zero clinical trials for cannabinoids in colorectal cancer

What the researchers found

Researchers reviewed the evidence on cannabinoids for inflammatory bowel disease (IBD) and colorectal cancer.

For IBD, in vitro and animal data showed cannabinoids reduce intestinal inflammation through multiple mechanisms. However, clinical evidence was limited to patient questionnaires and small pilot studies. No approved cannabinoid medications exist for IBD.

For colorectal cancer, only preclinical data were available showing anti-tumor effects of cannabinoids, with no clinical studies in humans.

The review noted that currently approved cannabinoid medications (THC, dronabinol, nabilone) are used for pain, spasticity, and chemotherapy-induced nausea, not for IBD or cancer treatment. Medical cannabis authorization remained limited to a small number of countries.

Why it matters

IBD and colorectal cancer are significant health burdens with limited treatment options. While the preclinical data on cannabinoids is encouraging, this review clearly delineates the gap between laboratory promise and clinical evidence, informing patients and clinicians about the current state of knowledge.

The numbers in context

Currently approved cannabinoid medications: THC/dronabinol/nabilone for nausea, dronabinol for anorexia, THC:CBD spray for MS spasticity and cancer pain, CBD for epilepsy. None indicated for IBD. Zero clinical trials for cannabinoids in colorectal cancer.

How the study worked

Narrative review of preclinical and clinical literature on cannabinoids in intestinal inflammation and gastrointestinal carcinogenesis.

What this study cannot tell us

Narrative review without systematic methodology. Heavy reliance on preclinical data for both conditions. The small pilot studies in IBD have significant methodological limitations. Cannabis self-medication by IBD patients is not well captured in clinical studies.

How to read the evidence

Review based heavily on preclinical data with only small uncontrolled clinical studies, providing preliminary evidence of therapeutic potential.

When this study was published

Published in 2018. Clinical research on cannabinoids for IBD has progressed with several new trials since publication.

The bigger picture

This review illustrates a common pattern in cannabinoid research: strong preclinical data that has not yet translated to clinical practice. For IBD in particular, where patients frequently self-medicate with cannabis, the disconnect between laboratory evidence and clinical validation is a significant concern.

Questions still open

Will randomized controlled trials of cannabinoids for IBD produce the results predicted by preclinical data? Which specific cannabinoids or combinations are most promising for intestinal inflammation? Could cannabinoids serve as adjunct therapy alongside standard IBD treatments?

Common questions

Can cannabis treat inflammatory bowel disease?

Preclinical evidence is promising, showing anti-inflammatory effects in lab and animal models. However, clinical evidence in humans is limited to questionnaires and small pilot studies. No cannabinoid medications are approved for IBD.

Can cannabinoids treat colorectal cancer?

Only preclinical (lab and animal) data exist showing anti-tumor effects. No human clinical trials had been conducted as of this review. Cannabinoids are currently used to manage chemotherapy side effects, not to treat cancer directly.

Read the original research

Medical Cannabis and Cannabinoids: An Option for the Treatment of Inflammatory Bowel Disease and Cancer of the Colon?

Medical cannabis and cannabinoids, 1(1), 28-35

View on PubMed ↗Publisher’s paper ↗

Citation

Grill, Magdalena; Hasenoehrl, Carina; Storr, Martin; Schicho, Rudolf. (2018). Medical Cannabis and Cannabinoids: An Option for the Treatment of Inflammatory Bowel Disease and Cancer of the Colon?. Medical cannabis and cannabinoids, 1(1), 28-35. https://doi.org/10.1159/000489036