Medical cannabis, while certainly not a “cure” for Crohn’s disease, produced marked symptom reductions in a cohort of patients for whom steroids, anti-tumor necrosis factor agents and immunomodulating drugs failed to give relief.
Investigators at the Meir Medical Center, Tel Aviv University randomized 21 patients to two groups: one was provided with two Cannabis sativa cigarettes per day, containing 11.5 mg THC, or “placebo” joints made of cannabis flowers from which the THC had been extracted.
The study group included 13 men and 8 women between the ages of 26 and 54. All had Crohn’s Disease Activity Index (CDAI) scores over 200, and had not responded to previous drug therapies. The objective of the study was to determine if smoking cannabis could produce complete remissions of Crohn’s—defined as a CDAI score reduction of 150 points or more.
The researchers assessed the patients & measured lab values at baseline, at 8 weeks, and again two weeks after cessation of the trial.
Five of the 11 people (45%) in the study group obtained complete remissions from the marijuana, compared to only 1 of the 10 (10%) in the placebo group. Ten of the 11 (90%who smoked the THC-containing cannabis had CDAI score reductions of greater than 100 points but fewer than 150, which is considered a “clinical response.” Four of the 10 (40%) in the placebo group had partial responses (Naftali T, et al. Clin Gastroenterol Hepatol. May 3, 2013: epub ahead of print).
The authors noted that those smoking the THC-containing herb had significant improvements in appetite, and sleep. Three were able to discontinue their steroid drugs.
The small size of the study group makes it difficult to draw a definitive conclusion that cannabis is therapeutic in people with Crohn’s. But this trial is not the first to suggest the possibility.
In 2009, British investigators reported that both THC and cannabidiol influence the permeability of the gut endothelium, and modulate gut inflammation. There is a high concentration of endocannabinoid receptors throughout the GI tract (Wright KL, et al. Br. J. Pharmacol 2008: 153(2), 263-70).
The new trial followed an observational study published by the same group in 2011, and involving 30 Crohn’s patients using cannabis. Of these, 21 had significant symptom improvements after commencing the treatment; many were able to decrease their use of other medications, and several were able to avoid surgeries during the 3-year observation period (Naftali T, et al. Isr Med Assoc J. 2011; 13(8):455-8).
Some researchers have suggested that while marijuana may provide relief, symptoms often return fairly soon after people stop smoking, so the effect is limited and does not fundamentally modulate the underlying disease process.
The Crohn’s & Colitis Foundation of America, while not endorsing the widespread use of medical marijuana as a treatment of these conditions, did acknowledge that some people do experience symptom relief.
In a January 2012 statement, CCFA noted the following:
“Experimental evidence suggests that endocannabanoids, molecules found in the body that closely resemble compounds found in the cannabis (marijuana) plant, may play a role in limiting intestinal inflammation. IBD patients have been found to have higher levels of cannabinoid receptors in their colonic tissue. Several small studies have shown that a significant proportion of patients with IBD report smoking marijuana to relieve IBD-related symptoms, particularly those patients with a history of abdominal surgery, chronic abdominal pain, and/or a low quality of life index. However, the medicinal use of marijuana is limited by potential side effects, the risk of smoking, and the lack of direct scientific evidence of clinical effectiveness for intestinal inflammation.”
While not supporting cannabis therapy, CCFA did call for a “review of marijuana’s status as a federal Schedule 1 controlled substance, with the goal of facilitating the conduct of clinical research and the potential development of cannabinoid-based medications.”
There were no significant side-effects from the use of cannabis in the new Israeli study. Still, investigators acknowledged that smoking marijuana is a questionable mode of treatment delivery, and called for a larger trial with “a non-smoking mode of intake.”
(Learn more about the clinical use of cannabis. Download a conversation with medical marijuana expert, Laura Lagano, and HPC’s editor, Erik Goldman)
END
