Cooperative Effects of Exercise and Food component on Bone Metabolism in Japanese Men.

Introduction : We recently demonstrated that the favorable effects of isoflavones and exercise on bone and lipid metabolism in postmenopausal Japanese women. In this study, we determined the effects of isoflavone intake, walking exercise, and their interaction on bone, fat mass, and mineral metabolism over 1 year in aged Japanese men. Methods : A total of 33 aged men (50〜75 years old) were randomly assigned to three groups: (1) placebo, (2) isoflavone intake (75 mg of isoflavone conjugates/day, 47mg/day of aglycone form), (3) combination of isoflavone plus walking (45 min/day, 3 days/week). Bone mineral density (BMD), fat mass, serum lipid, and serum and urinary isoflavone and mineral concentrations were assessed. Results : A significant main effect of walking exercise on the prevention in trunk fat mass gain was obtained at 6 months. Walking prevented bone loss at the right leg to significant degrees. The effect of the combined intervention on BMD and fat mass was greater than that of isoflavone alone. No significant interaction was observed between isoflavone and walking in any measurements recorded during the study. Conclusion : Our study suggest that combined intervention of 75 mg/day of isoflavone intake and walking exercise 3 times/week for 12 month showed a greater effect on BMD of Ward's triangle of hip than isoflavone alone. Further studies over longer treatment duration that include assessment of BMD at various regions are necessary to ascertain the clinical significance of the combined intervention of isoflavone plus walking in aged Japanese men.