I don’t smoke for my disease, but I know this is a topic of – ahem – burning interest in the IBD community. The study is titled “Δ9-Tetrahydrocannabinol (THC) enhances lipopolysaccharide-stimulated tissue factor in human monocytes and monocyte-derived microvesicles” — and I can barely make sense of it, too. So I emailed one of the authors, Dr. John Sleasman of Duke University, and he explained in detail.
The basic idea is that THC — the main ‘drug’ in marijuana — increases expression of tissue factor (TF), which is important to blood clotting. That means THC can increase the risk of clotting disorders — such as heart attack, deep vein thrombosis, and pulmonary embolism — which is already higher for people with inflammatory diseases.
But wait: there’s more. Another thing TF affects is TNF-alpha, an immune system component. THC elevates levels of TNF-alpha — by “20 to 50%” according to Dr. Sleasman’s research. Most of the ‘biologic’ drugs for IBD — Remicade, Humira, etc. — are anti-TNF-alpha; that is, they block this component of the immune system to decrease inflammation. So THC elevates what Remicade and Humira are designed to decrease, potentially increasing inflammation.
But don’t flush your stash just yet. The research was done in tissue models (ie. petri dishes); there was no testing of THC’s effect on humans or even actual animals. Says Dr. Sleasman: “Given the complexity of the human immune response and its high degree of self-regulation it would erroneous to conclude that THC use causes thrombosis or enhances inflammation.”
For what it’s worth, Crohnology members rate marijuana as one of the most effect medicines available for IBD. It may help that most IBD patients tend to favor high-CBD/low-THC strains, but the fact is: we don’t know. And we don’t know how that affects IBD, and we don’t even know what causes IBD, so there’s a lot more work to be done before we have good science on IBD and marijuana.
Says Dr. Sleasman, “You may not know how little we know about how THC influences the human immune system. We have even less knowledge about how factors that drive inflammation such as bacterial products. However our study is an important first step and hopefully we will continue to receive funding from NIH to continue to explore this important area of human immunology.”
Let’s hope they get that funding.
–Williams et al. “Δ9-Tetrahydrocannabinol (THC) enhances lipopolysaccharide-stimulated tissue factor in human monocytes and monocyte-derived microvesicles”. J. Inflamm (Lond). 2015; 12:39. Published online 2015 Jun 12. doi: 10.1186/s12950-015-0084-1
—Photo by Flickr User Taber Andrew Bain under a CC commercial/modification license.