The use of cannabis and cannabinoids does not induce clinical remission or improve inflammation in inflammatory bowel disease (IBD) patients, but it may help improve patient-reported symptoms and quality of life, according to research results published in the Journal of Clinical Gastroenterology.
Because of a high loss-of-response rate and side effects, many patients look to alternative therapies to ease IBD symptoms, including cannabis. While studies have shown promising results in patients with ulcerative colitis, study results on the effect of cannabis in IBD are mixed.
The authors conducted a systematic review and meta-analysis exploring the effect of cannabis and cannabinoids on people with IBD. The primary outcome was the efficacy of cannabis and cannabinoids on clinical remission; the secondary outcomes included inflammatory biomarkers, symptom improvement, quality of life scores, and hospital outcomes.
Study investigators searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials. The authors included randomized controlled trials and nonrandomized cohort, case control, and cross-sectional studies that identified the effect of cannabis and cannabinoids on IBD, Crohn disease, and ulcerative colitis symptoms. Conference abstracts and posters were also included. The authors excluded case reports, reviews, ex vivo and in vitro studies, and animal studies. Two reviewers assessed the randomized and nonrandomized trials for bias, and 20 studies fulfilled inclusion criteria.
Ultimately, the primary endpoint of remission induction was negative (risk ratio [RR] 1.56; 95% CI, 0.99-2.46), with no evidence of statistical heterogeneity (P =.49). Just 1 nonrandomized study found a significant RR in favor of cannabinoid use (RR 6.50, 95% CI, 1.60-26.36). Indices of posttreatment disease activity of patients in randomized controlled trials demonstrated a significant reduction with cannabis or cannabinoid use (standardized MD=0.61; 95% CI, 0.24-0.99), while 3 nonrandomized studies reported lower disease activity following cannabis or cannabinoid use.
No effect on inflammatory biomarkers was observed by investigators, but clinical symptoms — including abdominal pain, nausea, diarrhea, poor appetite, and general well-being — were all improved with cannabis or cannabinoid use.
Researchers also found that cannabinoids do not affect inflammatory biomarkers, the formation of strictures, fistula, abscesses, anemia, bowel obstruction, or the need for colectomy. The authors did find that people with IBD who used cannabinoids experienced shorter hospitals stays and less need for parenteral nutrition.
A positive correlation between cannabis use and patient-reported outcomes was also identified, with investigators hypothesizing that this is due to the effect of THC on the nervous system. Cannabis’s ability to reduce gastric and colonic motility may explain improvements on abdominal pain, nausea, and diarrhea, the authors wrote. Finally, patients who used cannabis or cannabinoids had a lower baseline quality of life, which significantly improved with cannabis or cannabinoid usage.
Study limitations include clinical heterogeneity between studies due to patient populations, the ability of researchers to perform only a few subgroup analyses due to the limited number of randomized controlled trials, and small sample sizes in most of the studies.
“Larger, more uniform trials are warranted since evidence is not sufficiently robust to reliably determine the effectiveness of [cannabis or cannabinoids].” The researchers concluded. “Until then, prescription of [cannabis or cannabinoids] should be issued with caution.”
Doeve BH, van de Meeberg MM, van Schaik FDM, Fidder HH. A Systematic Review With Meta-Analysis of the Efficacy of Cannabis and Cannabinoids for Inflammatory Bowel Disease: What Can We Learn From Randomized and Nonrandomized Studies? [published online July 14, 2020]. J Clin Gastroenterol. doi: 10.1097/MCG.0000000000001393