The first step was, of course, to get a bunch of mice high. The scientists adminstereed a cocktail of THC (which creates the recreational drug’s famous high) and cannabinoid cannabidiol, or CBD, to lab rats. Then, they compared the results to a separate group who received only CBD. The scientists found that THC had no benefit for healing bones. But CBD, which also occurs naturally in cannabis leaves and stems, proved to help mice recover from their fractures more effectively.
Researchers believe that CBD allows for more minerals to get into the healing bone tissue, creating a stronger, sturdier frame. According to lead scientist Yankel Gabet, that actually makes the bone harder to break again. This perk is independent of the, uh, side effects that come from THC. In other words, you don’t actually need to get high to see the benefits—doctors could theoretically isolate CBD for human medication in the future.
A new study shows that weed may actually help bones to heal—both faster, and stronger. Scientists at Tel Aviv University’s Sackler Faculty of Medicine tested out the effects of two different marijuana compounds for healing broken bones.
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Nyman said he’d take the study with a grain of salt because of its small size and the fact that the researchers did something unusual: After euthanizing the animals and extracting the healed femurs, the researchers coated those femurs with formalin, a preservative. (They did not say how diluted it was.) Then, they dehydrated and rehydrated the femurs before examining them, measuring the callusing as well as meximal force, stiffness and work to failure, which are measurements of strength.
“The main limitation is that this is the very first study on the matter and results have been obtained in animals only,” Gabet said.
Gabet and his team said that while they didn’t measure long term effects, previous studies have shown CBD to be safe.
— Forget the headlines you read. Here’s what you should know.
Gabet and his team methodically broke the rats’ femurs and administered THC, CBD, or a ethanol/emulphor/saline solution that served as a control to see how well the rats’ bones healed over eight weeks using 3D micro-computed tomography and biomechanical machines. As part of a second experiment, they tried a mixture of THC and CBD, THC alone and CBD alone. The third experiment in the study involved measuring how THC and CBD affected the enzymes that prompt collagen crosslinking in healing bones, and the researchers reported that CBD enhanced expression of the enzyme lysyl hydroxylase 1, or PLOD 1.
The study was published in the Journal of Bone and Mineral Research and has generated such pun-tastic headlines as “No Bones About It: Cannabis May be Used To Treat Fractures” and “Joint Relief: Marijuana Helps Mend Broken Bones.”
“It’s very clear to me that this is not accelerated healing,” Nyman said.
Each group had between 5 and 12 rats, which Nyman said was not ideal. And after the eight weeks were up, Gabet and his team euthanized the rats, removed the once-broken femurs and studied them after first coating them in formalin, dehydrating and rehydrating them.
Cannabinoid ligands regulate bone mass, but skeletal effects of cannabis (marijuana and hashish) have not been reported. Bone fractures are highly prevalent, involving prolonged immobilization and discomfort. Here we report that the major non-psychoactive cannabis constituent, cannabidiol (CBD), enhances the biomechanical properties of healing rat mid-femoral fractures. The maximal load and work-to-failure, but not the stiffness, of femurs from rats given a mixture of CBD and Δ(9) -tetrahydrocannabinol (THC) for 8 weeks were markedly increased by CBD. This effect is not shared by THC (the psychoactive component of cannabis), but THC potentiates the CBD stimulated work-to-failure at 6 weeks postfracture followed by attenuation of the CBD effect at 8 weeks. Using micro-computed tomography (μCT), the fracture callus size was transiently reduced by either CBD or THC 4 weeks after fracture but reached control level after 6 and 8 weeks. The callus material density was unaffected by CBD and/or THC. By contrast, CBD stimulated mRNA expression of Plod1 in primary osteoblast cultures, encoding an enzyme that catalyzes lysine hydroxylation, which is in turn involved in collagen crosslinking and stabilization. Using Fourier transform infrared (FTIR) spectroscopy we confirmed the increase in collagen crosslink ratio by CBD, which is likely to contribute to the improved biomechanical properties of the fracture callus. Taken together, these data show that CBD leads to improvement in fracture healing and demonstrate the critical mechanical role of collagen crosslinking enzymes.
Keywords: CANNABIDIOL; COLLAGEN CROSSLINKING; FRACTURE HEALING; FTIR; LYSYL HYDROXYLASE; μCT.