Sunday, July 21, 2013

Inflammatory Bowel Disease and Pot

Medical Marijuana and IBD

The great pot debate has been raging for several years.  While possessing marijuana is still a federal offense, many state governments have chosen to create medical marijuana exceptions to laws at a state level.  At a federal level, resource limitations and other priorities have limited any federal enforcement of medical marijuana providers at a state level. 

Medical marijuana has been proposed as a treatment for many conditions, ranging from glaucoma relief to its use as an anti-emetic by cancer patients.  This post focuses on the use of marijuana and cannabinoids on inflammatory bowel disease from a medical perspective, and does not address other uses of the drug or its legal status.

Marijuana has been shown to have a modulation effect on the cannabinoid receptors CB1 and CB2 in rat studies.  Because CB1 and CB2 are related to enteric and immune modulation, marijuana has the potential for impacting Crohn’s and Ulcerative Colitis patients (though positively or negatively is not known).(1)  There has been some human genetic research showing that CNR1, a human cannabinoid receptor, has a modulation effect on the susceptibility of an individual to Crohn’s and UC.(2)  There is even some evidence in mouse models of colitis that cannabidiol (not the psychotropic THC), an ingredient of marijuana, has a positive impact on intestinal protection.(3)

Marijuana has been postulated to have a positive effect on both Crohn’s disease and Ulcerative Colitis, however the evidence for it doing so is sparse.  The most cited study looking at the effects showed a positive increase in the health of individuals who used marijuana and had Crohn’s disease.  Unfortunately, the study only included 30 patients and was a retrospective (and uncontrolled) study.(4)  A smaller study, consisting of 21 patients, showed a positive change in CDAI scores vs. placebo in a prospective look.  This study used cigarettes with THC for the active and with the THC removed for the control, so the study was likely not blind to the users.(5)  To date, there have been no large-scale, well-controlled studies showing the efficacy of marijuana for IBD.

Marijuana consumption through smoking has many of the same associated negatives as nicotine-based smoking, though some to a lesser degree, including the impact on the lungs and the psychotropic effects (which can also be a positive in some circumstances).  Additionally, smoking marijuana has an impact on gastric motility, slowing down digestive function, which may be dangerous for individuals with structuring disease.(6)

If a particular cannabinoid can be isolated and taken orally to interact positively with the CB1 and CB2 receptors, it may open up a new treatment path for IBD.  Right now, smoking marijuana has known negative side effects (and the cannabinoid ratios are not well controlled), and has not shown efficacy in quality evidence-based studies for the treatment of Crohn’s and Ulcerative Colitis.  That said, preliminary studies show areas of promise, and cannabinoid extracts may prove an effective treatment with substantial testing and research (though more likely through oral administration than inhalation).

Bottom Line

·         Smoking marijuana to treat Crohn’s and Ulcerative Colitis has no solid proof of efficacy.
·         There are known negative side effects to smoking marijuana, and unless better evidence is uncovered, its use by those with IBD is not warranted.


1.       Tsou, K., S. Brown, M. C. Sanudo-Pena, K. Mackie, and J. M. Walker. "Immunohistochemical distribution of cannabinoid CB1 receptors in the rat central nervous system." Neuroscience 83, no. 2 (1997): 393-411.
2.       Storr, Martin, Dominik Emmerdinger, Julia Diegelmann, Simone Pfennig, Thomas Ochsenkühn, Burkhard Göke, Peter Lohse, and Stephan Brand. "The cannabinoid 1 receptor (CNR1) 1359 G/A polymorphism modulates susceptibility to ulcerative colitis and the phenotype in Crohn's disease." PLoS One 5, no. 2 (2010): e9453.
3.       Borrelli, Francesca, Gabriella Aviello, Barbara Romano, Pierangelo Orlando, Raffaele Capasso, Francesco Maiello, Federico Guadagno et al. "Cannabidiol, a safe and non-psychotropic ingredient of the marijuana plant Cannabis sativa, is protective in a murine model of colitis." Journal of molecular medicine 87, no. 11 (2009): 1111-1121.
4.       Naftali, T., L. Bar Lev, D. Yablecovitch, E. Half, and F. M. Konikoff. "Treatment of Crohn's disease with cannabis: an observational study." The Israel Medical Association journal: IMAJ 13, no. 8 (2011): 455.
5.       Naftali, Timna, Lihi Bar Lev, Iris Dotan, Ephraim Philip Lansky, Benjaminov Fabiana Sklerovsky, and Fred Meir Konikoff. "Cannabis Induces a Clinical Response in Patients with Crohn’s Disease: a Prospective Placebo-Controlled Study." Clinical Gastroenterology and Hepatology (2013).

6.       Aviello, G., B. Romano, and A. A. Izzo. "Cannabinoids and gastrointestinal motility: animal and human studies." Eur Rev Med Pharmacol Sci 12, no. Suppl 1 (2008): 81-93.

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