Kioka Kazuki, Fukazawa Hitomi, Omura Kanae, Higuchi Yuki, Mihara Toshihiro, Uchiyama Kimiko, Takahashi Hajime, Omi Naomi
Graduate School of Comprehensive Human Sciences, Doctoral Program in Physical Education, Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan.
Graduate School of Comprehensive Human Sciences, Master's Program in Physical Education, Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan.
Phys Act Nutr. 2025 Jun;29(2):70-76. doi: 10.20463/pan.2025.0016. Epub 2025 Jun 30.
Osteoporosis is a global health concern, particularly in developed countries with aging populations, where the incidence of postmenopausal osteoporosis is increasing. Various nutrients have been studied as potential interventions, and components derived from regionally familiar foods may enhance acceptability and adherence. In this study, we focused on rice, a staple food in Asia and Africa. Recent studies have suggested that rice-derived peptides may help prevent bone fragility. Therefore, we examined the effects of rice protein hydrolysate (RPH) on bone health in ovariectomized rats.
In Study 1, which was designed to prevent osteoporosis, 5-week-old female Sprague-Dawley rats were acclimated for one week and then underwent ovariectomy (OVX). They were divided into three groups: a control group fed a normal diet and two experimental groups fed diets containing 0.01% or 0.1% RPH for eight weeks. In Study 2, which aimed at promoting recovery from osteoporosis, the setup was similar; however, after OVX, rats were fed a low-calcium diet for four weeks to induce osteoporosis, followed by the same diet groups as in Study 1 for an additional four weeks.
Study 1 showed that RPH significantly increased bone-breaking force (0.01% RPH, p < 0.01; 0.1% RPH, p < 0.05). In Study 2, RPH intake reduced serum tartrate-resistant acid phosphatase (TRAP) levels, a marker of bone resorption (both p < 0.05). However, a significant effect on bone mineral density was observed only in the 0.01% RPH group in Study 1 (p < 0.05).
These findings suggested that RPH may help treat postmenopausal osteoporosis.
骨质疏松是一个全球性的健康问题，在人口老龄化的发达国家尤为突出，绝经后骨质疏松的发病率正在上升。人们对各种营养素作为潜在干预措施进行了研究，源自当地常见食物的成分可能会提高可接受性和依从性。在本研究中，我们重点关注大米，它是亚洲和非洲的主食。最近的研究表明，大米衍生肽可能有助于预防骨质脆弱。因此，我们研究了大米蛋白水解物（RPH）对去卵巢大鼠骨骼健康的影响。
在旨在预防骨质疏松的研究1中，5周龄的雌性斯普拉格-道利大鼠适应一周后进行卵巢切除术（OVX）。它们被分为三组：对照组喂食正常饮食，两个实验组分别喂食含0.01%或0.1%RPH的饮食，持续八周。在旨在促进骨质疏松恢复的研究2中，设置类似；然而，在OVX后，大鼠先喂食四周低钙饮食以诱导骨质疏松，然后再按照研究1中的相同饮食组喂养四周。
研究1表明，RPH显著增加了骨折力（0.01%RPH，p<0.01；0.1%RPH，p<0.05）。在研究2中，摄入RPH降低了血清抗酒石酸酸性磷酸酶（TRAP）水平，这是骨吸收的一个指标（两者p<0.05）。然而，仅在研究1的0.01%RPH组中观察到对骨矿物质密度有显著影响（p<0.05）。
这些发现表明，RPH可能有助于治疗绝经后骨质疏松症。
