A Study of the Effect of Diet and Physical Activity on Bone Metabolism

(JSNFS Award for Excellence in Research (2018))

Abstract

Various health plans have been proposed in Japan in order to extend healthy life expectancy. We have accumulated scientific evidence related to lifestyle factors that are beneficial for preservation of bone health. First, we have screened nutrients and food components that affect bone metabolism using osteoblast and osteoclast formation assay systems. Vitamin A and vitamin K derivatives as well as soybean isoflavones appeared to be likely candidates. Since isoflavones have been a focus of attention because of their weak estrogenic activity as phytoestrogens, we have assessed the safety and efficacy of isoflavones, and their cooperative effects with exercise on bone metabolism in postmenopausal healthy Japanese women as well as an animal model of osteoporosis. On the other hand, we have demonstrated that undigestible carbohydrates stimulate the production of equol, which seems to be an active form of isoflavone, from isoflavone daidzein by gut microbiota. Finally, a dietary pattern for preservation of healthy bone has been proposed. These results are considered to be helpful for devising measures for the elderly in health plans.