Phytocannabinoids May Support Bone Health and Fracture Healing, Finds New Review

A new scientific review concludes that cannabis-derived phytocannabinoids may have beneficial effects on bone health, including promoting fracture healing, reducing bone loss and decreasing fracture-related pain.

The review, published September 8 in Current Osteoporosis Reports, was conducted by researchers at Rutgers University. Researchers examined recent laboratory, animal and human studies on how phytocannabinoids affect bone metabolism and healing.

“Phytocannabinoids may improve bone health,” states researchers, while noting that additional studies are needed to determine optimal doses, timing and methods of administration.

CBD was by far the most extensively studied cannabinoid. Laboratory research indicates that CBD can inhibit osteoclasts, cells responsible for breaking down bone tissue, while promoting the activity and differentiation of osteoblasts, which produce new bone.

Animal studies have produced evidence that CBD could help prevent or reduce osteoporosis-related bone loss. The researchers note that “CBD was shown to improve bone quality” in mice when administered as an early intervention. In that study, CBD restored reductions in whole-body and femoral bone mineral density and improved trabecular bone quality. Another study found CBD improved bone volume and the mechanical strength of bones in rats with experimentally induced bone loss.

Other research, however, has produced mixed results, with one study finding that long-term CBD treatment did not restore osteoporosis-related trabecular bone loss. The review says differences between studies may be related to the method of CBD administration, interactions with the gut microbiome and the age at which treatment began. Researchers said additional studies are needed to determine the optimal timing and dosage.

The review also highlighted evidence involving fractures, with researchers finding that several animal studies suggest CBD can promote bone healing while simultaneously reducing fracture pain.

In one experiment involving tibial fractures, CBD and cannabigerol (CBG) “increased bone volume fraction, BMD, and strength and decreased pain.” Another study found CBD, but not THC, improved the maximum load fractured bones could withstand and the amount of energy they could absorb before failing. Researchers said CBD may enhance collagen crosslinking, potentially helping explain its effects on bone strength.

CBD has also demonstrated potential benefits for periodontal bone health, with the researchers saying phytocannabinoids “may support periodontal health.” Animal studies found CBD reduced inflammation and alveolar bone loss associated with periodontitis, while laboratory research using human bone-derived cells found CBD enhanced osteogenic differentiation and biomineralization.

Evidence involving humans remains much more limited.

Researchers highlighted what they called the “first clinical study to test the effects of two medical cannabis products” on bone health. The study involved 83 healthy adults, including 38 men and 45 women, who received softgels containing between 5 and 20 milligrams of THC, with varying levels of CBD, twice daily for seven days.

Both cannabis products reduced blood levels of CTx, a marker associated with bone resorption, while “markers of bone formation were unchanged.” Researchers said the findings suggest cannabinoids may influence bone metabolism, although it remains unknown whether they can increase bone strength, density or quality in humans.

The review also noted mixed findings for cannabinoids other than CBD. In an osteoarthritis model, CBG reduced cartilage degeneration, chondrocyte loss and expression of an enzyme involved in cartilage breakdown, leading researchers to conclude that “CBG oil is chondroprotective.” Separate research found that CBG, like CBD, increased bone volume, bone mineral density and strength while reducing fracture pain.

Cannabichromene (CBC), meanwhile, demonstrated a more complicated effect. In a mouse model of tibial fracture, CBC reduced fracture pain but impaired bone repair, underscoring researchers’ conclusion that different cannabinoids can have substantially different effects on bone.

Researchers said more clinical studies are needed to determine how individual cannabinoids, combinations of cannabinoids, sex, dosage and administration method affect bone health.

“CBD is the primary phytocannabinoid that has received attention for improving bone health,” the authors concluded, adding that initial human findings are promising but remain insufficient to determine whether cannabinoids improve bone strength or bone mineral density in people.