The role of polyphenols on bone metabolism in osteoporosis

Osteoporosis is a skeletal disease of bone mass loss and deterioration of the bone structure leading to increased susceptibility to fracture, generally associated with risk factors that include hormonal imbalance, increased oxidative stress and chronic inflammation. Nutritional factors and certain lifestyle reduce the risks of occurrence of osteoporosis and are part of a number of national and international prevention recommendations. Recent reports based on molecular mechanisms of dietary polyphenols have highlighted the benefits in their prevention and treatment of osteoporosis. Polyphenols can protect bone health through reduction of oxidative stress because they act as antioxidants, reduction of inflammation by proinflammatory signaling, modulation of osteoblastogenesis, osteoclastogenesis, and osteoimmunological action. This review reports about some important bioactive polyphenol sources and describes their action against osteoporosis based on in vitro and in vivo studies. (C) 2015 Elsevier Ltd. All rights reserved.