Abstract
Osteoporosis is a skeletal disorder characterized by reduced bone strength and an increased risk of fractures. Bone strength is exacerbated by various factors that influence bone mineral density (BMD) and bone quality with increasing age. We have developed a novel supplement diet for osteoporosis prevention that contains fructo-oligosaccharide, isoflavone, and calcium citrate in addition to calcium phosphate (high mineral diet: HMD), thereby increasing the Ca and P content. The present study aimed to clarify whether rats with osteoporosis fed a HMD showed improved BMD compared with rats fed a normal mineral diet (NMD). The experiment used 20-week-old ovariectomized rats divided into an NMD group (Group 2, n=8) and a HMD group (Group 3, n=8). This study also used 20-week-old sham-ovariectomized rats fed NMD as controls (Group 1, n=8). After 8 weeks and 24 weeks on the diet, this study examined the changes in BMD, bone mineral content (BMC), and 3-dimensional (3D)-map using micro-computed tomography (CT) imaging of the shaft of the femur. In the 3D-map, both Groups 1 and 3 showed high BMD on the inner portion of the cortical bone, while Group 2 showed slightly lower BMD at the same location. Decreased estrogen secretion in Group 2 significantly affected bone metabolism, lowering both BMD and BMC compared to Group 1. However, while Group 3 also showed decreased estrogen secretion, BMD and BMC were higher than in Group 2. These findings indicate that HMD increases both BMD and BMC, and is therefore more effective than NMD for improving BMD and bone quality.
