The relationship between the endocannabinoid system (ECS) and bone density regulation is well established, but there is very little research on the efficacy of cannabis in the treatment of osteoporosis. In fact, evidence suggests that cannabis could harm bone growth. 

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The Endocannabinoid System’s Role in Regulating Bone Density

Before cannabis was specifically identified as a potential trigger of osteoporosis, researchers discovered that the ECS played a role in the onset of the disease. A 2005 Natural Medicine study determined that the activation of CB1 receptors played a role in reducing bone mass and ovariectomy induced bone loss in mice. This relationship led the researchers to suggest in the study that “recreational or therapeutic use of cannabis derivatives...might enhance bone loss and predispose to osteoporosis.”    While the impact of the ECS is being studied, according to Dr. Tiab and research, the best ways to prevent osteoporosis are:

  • A diet plentiful in calcium
  • Vitamin D
  • Weight-bearing exercise
  • Cigarette avoidance

Targeting CB2 Receptors Could Slow Osteoporosis

That being said, in a 2017 review, researchers showed when targeting specific cannabinoid receptors (CB2), they were able to slow osteoporosis and reduce bone pain.  The authors of the review urged for the continued study of specific cannabinoids to identify which ones could safely target CB2 receptors.

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CBD Could Reduce Bone Loss 

A 2017 European Journal of Pharmacology study analyzed the effect of CBD on the loss of BMD in rats. The rats’ spines were surgically impaired and then treated with CBD for the following 14 days.  The results were promising: CBD increased the production of bone forming agents and enhanced the quantity and quality of bone tissue in the spine.  The researchers determined that CBD had successfully treated spinal cord injury induced bone loss in an animal model. More research will need to be done to understand how this translates to human patients. 

Evidence Implicating Cannabis in the Onset of Osteoporosis is Weak 

In 2009, a BMJ Case Reports released a study by professor Albert Reese implicated heavy cannabis use in the exacerbation of multi-organ cystic disease, a condition characterized by the progression of multiple diseases which cause cysts to develop throughout the body.  The study examined one patient, a 56-year-old man who demonstrated lethargy and a low tolerance for exercise. The man consumed up to 6 tobacco cigarettes a day, up to 7 grams of cannabis a day, and large quantities of hashish oil.

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He reported consuming cannabis from the age of 22 to 47. The man was found to have dozens of cysts in the lungs and bone density levels falling in the osteoporotic range. The researchers concluded that his severe condition was the result of multi-organ cystic disease “exacerbated by the smoking of tobacco, cannabis, and asthma.”  Although Reese’s study presents apparently damning evidence against cannabis, it’s problematic for several reasons.

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Correlation does not equal causation 

First, the study does not adequately deal with the causation.  It’s unclear whether the man developed cysts and suffered bone loss because he consumed a lot of weed or if he consumed a lot of weed because of his extremely uncomfortable physical symptoms.  Cannabis has been identified to possess bronchodilation and pain-relieving qualities, so it’s possible that the patient was consuming large quantities of marijuana because the plant alleviated his symptoms.

Additionally, Reese blames cannabis for the man’s deteriorating dental health, citing a craving for sweets while high. However, the report does not describe the man’s dental health regimen.  If the patient ate a large amount of sweets but regularly flossed and brushed his teeth, periodontal disease may not be apparent.

Unfortunately, we don’t know the man’s oral hygiene routine because that information is missing from the study.  A 2017 Archives of Osteoporosis study introduced additional doubt to the idea that cannabis is responsible for osteoporosis. The study gathered data from a national survey of people aged 20 to 59 years old, to determine the relationship between former, light, and heavy cannabis use and decreased bone mineral density (BMD) of the hip or spine. The researchers concluded they could not find a correlation between a history of cannabis use and BMD.

Diet and exercise is more proven to affect bone health

Another 2017 study by Dr. Antonia Sophocleous presented limited evidence associating cannabis with low bone mineral density. Researchers found that the increased risk of fractures and reduced bone density was an indirect symptom of heavy cannabis use due to low BMI.

That is, cannabis use may reduce BMI, and reduced BMI may be associated with reduced BMD. While this American Journal of Medicine study could not provide strong causal evidence linking cannabis use to decreased bone density, it did make two important observations.  First, Sophocleous’ research does seem to show a link between cannabinoids and the body’s ability to conduct bone resorption. Bones are in a constant state of growth—bone cells called osteoclasts basically recycle themselves to promote bone growth. But most importantly, Sophocleous’ results are a reminder that taking care of your body by exercising and eating healthy foods is an effective way to mitigate the risk of developing osteoporosis later in life.

For now, this means that pot smokers should continue to maintain an active lifestyle and nutritious diet while remaining cautious about the impact their cannabis use can have on their bones.

This information is presented for educational purposes only, and is not intended to diagnose, treat, cure or prevent any medical condition.  Please always consult your own doctor.