Another research paper has just been published that shows how plant based compounds can help to contain the brittle bone disease, osteoporosis. Scientists at the Institute of Medical Sciences, University of Aberdeen, UK have discovered how a non-psychoactive compound in cannabis, cannabidiol helps to maintain bone strength.

The endocannabinoid system is a group of cell receptors that are activated by a group of endogenous lipids as well as compounds derived from the cannabis plant. The cannabinoid receptors are known to be involved in a variety of physiological processes including appetite control, pain, memory and mood. Recent research has shown that the endocannabinoid system also has a strong influence on bone metabolism; as the receptors are well represented on osteoclasts – cells whose principal function is to resorb (thin out) bone.

Bone is an active, living tissue that is being continuously formed, remodeled and shaped in response to both physical and physiological needs of the body. Bone matrix consists primarily of the macronutrients calcium, magnesium and phosphate and is the material that makes up both the dense parts of the bone and the bone marrow framework. Many people still believe that if one eats foods rich in these minerals then they will avoid developing osteoporosis. Epidemiological and other evidence suggests that this is not necessarily the case.

When it comes to bone health and disease the integrated processes that control the formation and resorption bone are just as important as the availability of calcium, magnesium and phosphate.

Bone is a dynamic tissue the matrix of which is controlled by two main cell types: osteoblasts are bone cells that are responsible for the formation of bone matrix while osteoclasts are modified white blood cells responsible for the resorption of bone tissue.

These two cell types are controlled by a complex set of signaling hormones, proteins and cell receptors that respond according to the ever-changing demands on bone tissue and other physiological processes. If there are too many osteoclasts, or if these cells become overactive, they will resorb more matrix than the osteoblasts can produce. A predominance of osteoclast activity results in the bone becoming less dense – the principal characteristic of the clinical condition known as osteoporosis.

The Aberdeen researchers have discovered that cannabidiol binds to a specific cannabinoid receptor on the bone-resorbing osteoblast cells. By so doing it inhibits these cells from resorbing the bone matrix – thereby helping to prevent further weakening of the bones.

This is not the first time that plant compounds have been shown to influence bone metabolism in favour of stronger bones. In January 2009 researchers at Oklahoma State University found that, even in the presence of oxidative stress and systemic inflammation, polyphenols derived from plums inhibit the action of the bone-softening osteoclasts while enhancing the generation and activity of bone-building osteoblasts.

For those who think that smoking pot will help to strengthen their bones, they do so in vain. Although wild cannabis contains up to 40% cannabidiol, cultivated varieties contain very little of this compound. The important point to come out of this research, in my opinion, is that it shows how vital plant compounds are in the prevention of chronic degenerative diseases such as osteoporosis. There are bound to be many other phytonutrients in other food plants that have a positive influence on bone metabolism – they just have not been "discovered" yet.

While we wait for that research to be carried out, it is important to eat (not smoke) a wide range of vegetables, fruit and spices to ensure an adequate intake of a host of beneficial phytonutrients.  

References:

1. The putative cannabinoid receptor GPR55 affects osteoclast function in vitro and bone mass in vivo. PNAS, September 1, 2009, 106 (35) Whytea LS, et. al

2. Dried plum polyphenols attenuate the detrimental effects of TNF-alpha on osteoblast function coincident with up-regulation of Runx2, Osterix and IGF-I, J Nutr Biochem. 2009 Jan;20(1):35-44. Epub 2008 May 20. Bu SY, Hunt TS, Smith BJ

3. Dried plum polyphenols inhibit osteoclastogenesis by downregulating NFATc1 and inflammatory mediators.Calcif Tissue Int. 2008 Jun;82(6):475-88.   Bu SY, Lerner M, Stoecker BJ, Boldrin E, Brackett DJ, Lucas EA, Smith BJ.