Scottish scientists are investigating whether taking cannabis damages users' bones in a bid to find new treatments for osteoporosis.

Researchers at Edinburgh University are recruiting 200 heavy cannabis users from surgeries to discover more about the effect the drug has on the skeleton.

Previous research by the team has shown that chemicals produced in the body - called cannabinoids - have important effects on bone.

Receptors for these substances are in bone cells where they play a crucial role in both thinning of bones after the menopause and in promoting new bone formation.

It is known that components of cannabis trigger the same receptors but it is unclear whether they activate processes which could cause osteoporosis or protect against it.

Stuart Ralston, Arthritis Research Campaign (ARC) professor of rheumatology at the Institute of Genetics and Molecular Medicine, based at Edinburgh University, is leading the research.

He said: "This will be an important first step to determine if new cannabinoid receptor-based treatments are likely to be of value in the fight against osteoporosis.

"This is an exciting discovery because it opens up the possibility that we can develop new drug treatments for osteoporosis which bind to cannabinoid receptors to prevent bone loss and promote bone formation.

"We will also take account of cannabis users' diet, exercise and alcohol intake, since these are also known to influence bone health."

One in two women and one in five men are likely to suffer from osteoporosis, or brittle bone disease, which causes 200,000 fractures a year, including 86,000 broken hips.

Existing drugs cause side-effects. The cannabis study is being funded by the ARC as part of a £894,000 research programme.