It may be a good idea when the “munchies” set in that marijuana users reach for more calcium-rich foods, as a new study from the University of Edinburgh has just released data showing that people who regularly smoke large amounts of cannabis have reduced bone density and are more prone to fractures. Moreover, investigators found that heavy marijuana users have a lower body weight and a reduced body mass index (BMI), which could contribute to thinning of their bones.
“Our research has shown that heavy users of cannabis have quite a large reduction in bone density compared with nonusers and there is a real concern that this may put them at increased risk of developing osteoporosis and fractures later in life,” explained senior study investigator Stuart Ralston, M.D., professor at the University of Edinburgh’s Centre for Genomic and Experimental Medicine.
The Edinburgh team assessed 170 people who smoke cannabis regularly for recreational purposes and 114 nonusers from 2011 to 2013. Smokers were further subdivided into moderate (n = 56) or heavy-user (n = 144) subgroups, depending on whether they had reported fewer or more than 5000 cannabis smoking episodes during their lifetime. The researchers utilized a specialized X-ray technique called dual-energy X-ray absorptiometry (DXA) to measure the bone density of study participants. They found that the bone density of heavy cannabis users was about 5% lower than cigarette smokers who did not use cannabis.
The findings from this study were published recently in The American Journal of Medicine in an article entitled “Heavy Cannabis Use Is Associated with Low Bone Mineral Density and an Increased Risk of Fractures.”
Interestingly, the researchers also found that fractures were more common in heavy users compared to nonusers. However, moderate users showed no difference from nonusers. Furthermore, since smoking cannabis is often associated with increased appetite, the investigators were surprised to find that heavy cannabis users had a lower body weight and BMI than nonusers. The scientists speculated that this could be a result of cannabis reducing appetite when taken in large amounts over an extended period of time.
While the findings from this paper are preliminary and require further research, this is one of the first studies to investigate bone health amongst cannabis users. To that end, the research team looked for osteoporosis biomarkers and cellular mechanisms that could contribute to bone density loss.
“When compared with controls, serum cross-linked C-telopeptide of type 1 collagen (CTX) concentrations were raised in heavy cannabis users, as were serum N-terminal propeptide of type 1 procollagen (P1NP) concentrations,” the authors wrote. “However, serum total 25-hydroxyvitamin D concentrations were reduced in heavy users compared with controls.”
“We have known for a while that the components of cannabis can affect bone cell function, but we had no idea up until now of what this might mean to people who use cannabis on a regular basis,” concluded Dr. Ralston.