Meta-analysis of the Therapeutic Impact of Cannabinoids in Inflammatory Bowel Disease.

Background: With the increasing legalization of medical and recreational cannabis, patients and providers have growing interest in the role of cannabinoids in treating inflammatory bowel disease. Prior meta-analysis has shown inconclusive evidence for efficacy of cannabinoids. We sought to produce an up-to-date meta-analysis that pools new data to evaluate the therapeutic effects of cannabinoids in both Crohn's disease (CD) and ulcerative colitis (UC).

Methods: PubMed, Embase, CENTRAL and CINAHL were queried for randomized-controlled trials evaluating the impact cannabinoids in CD or UC. Random effects modeling was used to compute pooled estimates of risk difference. Heterogeneity was assessed using I2.

Results: Eight studies, including 4 studies of CD, 3 studies of UC, and 1 study of both diseases met inclusion criteria. Among 5 studies of CD, a statistically significant decrease in clinical disease activity following intervention was observed (risk ratios [RR],  -0.91; 95% CI, CI:1.54 to CI:0.28, I2 = 71.9%). Clinical disease activity in UC was not significantly lower in the pooled analysis (RR, -2.13; 95% CI, -4.80 to 0.55; I2 = 90.3%). Improvement in quality of life (QoL) was observed in both CD and UC combined (RR, 1.79; 95% CI, 0.92-0.2.66; I2 = 82.8%), as well as individually. No differences were observed in the analysis on endoscopic disease activity and inflammatory markers.

Conclusions: This meta-analysis of clinical trials suggests that cannabinoids are associated with improved quality of life in both CD and UC, as well as improved disease activity but not inflammation.