Yan Lin, Graef George L, Nielsen Forrest H, Johnson LuAnn K, Cao Jay
US Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, Grand Forks, ND 58202.
Department of Agronomy, University of Nebraska-Lincoln, Lincoln, NE 68583.
Nutr Res. 2015 Jun;35(6):523-31. doi: 10.1016/j.nutres.2015.04.012. Epub 2015 Apr 18.
Physical activity and soy protein isolate (SPI) augmentation have been reported to be beneficial for bone health. We hypothesized that combining voluntary running and SPI intake would alleviate detrimental changes in bone induced by a high-fat diet. A 2 × 2 × 2 experiment was designed with diets containing 16% or 45% of energy as corn oil and 20% SPI or casein fed to sedentary or running male C57BL/6 mice for 14 weeks. Distal femurs were assessed for microstructural changes. The high-fat diet significantly decreased trabecular number (Tb.N) and bone mineral density (BMD) and increased trabecular separation (Tb.Sp). Soy protein instead of casein, regardless of fat content, in the diet significantly increased bone volume fraction, Tb.N, connectivity density, and BMD and decreased Tb.Sp. Voluntary running, regardless of fat content, significantly decreased bone volume fraction, Tb.N, connectivity density, and BMD and increased Tb.Sp. The high-fat diet significantly decreased osteocalcin and increased tartrate-resistant acid phosphatase 5b (TRAP 5b) concentrations in plasma. Plasma concentrations of osteocalcin were increased by both SPI and running. Running alleviated the increase in TRAP 5b induced by the high-fat diet. These findings demonstrate that a high-fat diet is deleterious, and SPI is beneficial to trabecular bone properties. The deleterious effect of voluntary running on trabecular structural characteristics indicates that there may be a maximal threshold of running beyond which beneficial effects cease and detrimental effects occur. Increases in plasma osteocalcin and decreases in plasma TRAP 5b in running mice suggest that a compensatory response occurs to counteract the detrimental effects of excessive running.
据报道，体育活动和补充大豆分离蛋白（SPI）对骨骼健康有益。我们假设，将自愿跑步与摄入SPI相结合可以减轻高脂饮食引起的骨骼有害变化。设计了一项2×2×2实验，将含有16%或45%能量的玉米油以及20%SPI或酪蛋白的饮食喂给久坐不动或跑步的雄性C57BL/6小鼠14周。评估股骨远端的微观结构变化。高脂饮食显著降低了骨小梁数量（Tb.N）和骨矿物质密度（BMD），并增加了骨小梁间距（Tb.Sp）。饮食中用大豆蛋白代替酪蛋白，无论脂肪含量如何，均显著增加了骨体积分数、Tb.N、连通性密度和BMD，并降低了Tb.Sp。自愿跑步，无论脂肪含量如何，均显著降低了骨体积分数、Tb.N、连通性密度和BMD，并增加了Tb.Sp。高脂饮食显著降低了血浆骨钙素水平，并增加了抗酒石酸酸性磷酸酶5b（TRAP 5b）的浓度。SPI和跑步均提高了血浆骨钙素浓度。跑步减轻了高脂饮食诱导的TRAP 5b升高。这些发现表明，高脂饮食是有害的，而SPI对骨小梁特性有益。自愿跑步对骨小梁结构特征的有害影响表明，可能存在一个跑步的最大阈值，超过该阈值有益作用停止而有害作用出现。跑步小鼠血浆骨钙素增加和血浆TRAP 5b降低表明发生了一种代偿反应以抵消过度跑步的有害影响。
