Bone loss reduced by blocking body's cannabis-like substances

May 23 2005

British scientists have discovered that blocking the action of cannabis-like substances produced naturally by the body can reduce bone loss and they hope this finding will lead to new drugs to treat osteoporosis and other bone diseases.

Their research also suggests that using cannabis might have a damaging effect on the health of bones.

The research, led by the University of Aberdeen, focused on the effects on the bones of chemicals called endogenous cannabinoids.

These substances operate by attaching themselves to receptors in our body which then play a part in a number of the body's processes, including controlling our appetite, in much the same way that cannabis does.

This latest study shows that these receptors are also present in bone cells and play a crucial role in regulating bone density and the turnover of bone tissue. They also discovered that drugs which block the cannabinoid receptors proved highly effective in preventing bone loss.

Lead researcher Professor Stuart Ralston, now at the University of Edinburgh, says that this is an important finding as it demonstrates that the receptors which cannabis acts upon are not only important in the nervous system, but also in the control of bone metabolism.

He says it is a particularly exciting fact that compounds which blocked cannabinoid receptors are highly effective at preventing bone loss since it shows that these drugs could provide a completely new approach to the treatment of osteoporosis and other bone diseases.

Dr Ruth Ross, a cannabinoid research scientist at the University of Aberdeen, says they have found that cannabinoid receptor blockers have recently been shown to be safe and effective for the treatment of obesity, that they may also be potent inhibitors of bone loss has major therapeutic implications.

Drugs which stimulate these receptors and mimic the effects of cannabis were found to be detrimental to bone and caused increased bone loss which could, in turn, lead to osteoporosis.

More than 250,000 people in Britain suffer osteoporosis-related fractures each year, with related health care costs of over £1.7 billion, and the most widely used drug treatments for osteoporosis, cancer-related bone diseases, rheumatoid arthritis and other bone diseases are inconvenient to take and are often associated with undesirable side effects.

According to Professor Ralston there is a real need to identify new drugs that can inhibit bone loss, and blockers of cannabinoid receptors may be a possible new class of drugs for the treatment of bone disease.

A spokesman for the National Osteoporosis Society says the research is very encouraging and that osteoporosis research and funding is being made available to carry out this vital work.

He says that though the area of study is still at the very early stages, it is always interesting to hear about new research and they will watch with interest to see what happens.

The research is published in the current edition of the journal Nature Medicine.