Heavy cannabis use linked to reduced bone density
People who regularly smoke large amounts of cannabis have reduced bone density and are more prone to fractures, according to a new study.
Scientists at the University of Edinburgh compared 170 people who regularly smoke cannabis with 114 non-users using a specialised X-ray technique called Dexa, which measures bone density.
They found heavy cannabis users have 5% less bone density than cigarette smokers who do not use cannabis, as well as having a lower body weight and reduced body mass index (BMI).
Researchers say this could contribute to the thinning of cannabis users' bones, which could lead to a greater risk of osteoporosis in later life.
As a result of this, it was found that fractures were more common in heavy users, while there was no difference observed with moderate users of the drug.
The study, funded by Arthritis Research UK and published in the American Journal of Medicine, defined heavy cannabis users as those who smoke it on 5,000 or more occasions in their lifetime.
In the research, however, the average heavy cannabis user had taken the drug more than 47,000 times while moderate users had done so about 1,000 times.
Smoking cannabis is often associated with an increased appetite, so researchers said they were surprised to find heavy users had a lower BMI than non-users.
Researchers said this could be explained by cannabis reducing the appetite of heavy users when taken in large amounts over a long period of time.
The study is the first to investigate bone health amongst cannabis users, with researchers concluding that further studies are needed to better understand the link between the use of the drug and thinning of bones.
Lead researcher Professor Stuart Ralston, of the university's Centre for Genomic and Experimental Medicine, said: "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.
"Our research has shown that heavy users of cannabis have quite a large reduction in bone density compared with non-users and there is a real concern that this may put them at increased risk of developing osteoporosis and fractures later in life."