Polyphenols have been linked to physiological effects on bone mineral density and bone metabolism
Fruits and vegetables are thought to be important in maintaining bone health, in part because they contain polyphenols, micronutrients known to have effects against degenerative diseases. Polyphenols are linked to physiological effects on bone mineral density and bone metabolism, making them potentially useful in promoting bone health.
Bone is constantly remodelling, through the processes of resorption and formation. Because of this ongoing remodelling, the human body renews approximately 10% of its bone each year. That means that every 7-10 years, the skeleton is entirely regenerated. Supporting this process through nutritional intervention may help to protect bone health against age-related bone disease, such as osteoporosis.
A 28-day open-label study whose results were published in Phytomedicine in 2016 sought to identify botanical combinations that would affect bone resorption or formation. In this study, 46 postmenopausal women were randomised into three groups, each receiving one of three investigational combinations of plant extracts: an anti-resorptive combination of pomegranate fruit (Punica granatum L.) and grape seed (Vitis vinifera L.) extracts; a bone formation combination of quercetin (Dimorphandra mollis Benth) and licorice (Glycyrrhiza glabra L.) extracts; and a fixed combination of all four plant extracts.
Using standard microarray gene analyses of peripheral whole blood, researchers found that the combination of pomegranate fruit (Punica granatum L.) and grape seed (Vitis vinifera L.) maintained bone mass by preventing calcium loss. The extracts inhibited the expression of receptor activator of nuclear factor kappa-B ligand (RANKL), which is involved in osteoclast differentiation. The study also found that quercetin (from Dimorphandra mollis Benth) and licorice (Glycyrrhiza glabra) maintained bone mass by stimulating the formation of bone as well as enhancing calcium deposition.
While this study did show that these botanical combinations modulated gene expressions for bone remodelling, it was only an ex vivo microarray study, which means it’s premature to infer practical insights from it. Clinical trials in humans, which ideally would be of long enough duration to measure changes in bone mineral density, are necessary to determine whether these results are significant in practice.