AUTHOR=Tan Yao , Xu Anwei , Qiu Zhiqun , Wang Lingqiao , Wang Jia , Luo Jiaohua , Zeng Hui , Jin Huidong , Wang Yushu , Xue Jing , Huang Yujing , Shu Weiqun 

TITLE=Drinking Natural Mineral Water Maintains Bone Health in Young Rats With Metabolic Acidosis

JOURNAL=Frontiers in Nutrition

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.813202

DOI=10.3389/fnut.2022.813202

ISSN=2296-861X

ABSTRACT=<sec><title>Introduction</title><p>Metabolic acidosis affects bone health. It remains unclear whether drinking natural mineral water is better for maintaining bone health in the youth with metabolic acidosis.</p></sec><sec><title>Materials and Methods</title><p>Sixty young female rats (3-weeks-old) were randomly divided into three groups and drank purified water (PW, as control), bicarbonate-rich natural mineral water (Bic-NMW), or sulfate-rich natural mineral water (Sul-NMW), which, respectively, contained calcium (0.17, 155, and 175 mg/L), bicarbonate (0.1360, and 139 mg/L) and sulfate (0, 35.6, and 532 mg/L), for 16 weeks. In the last 3 weeks, metabolic acidosis was induced in 10 rats per group by adding NH<sub>4</sub>Cl (0.28 mM) to drinking water. The rats' blood, urine, and femur were collected for assessing acid-base status, calcium metabolism, bone microstructure, and strength. The difference between the three groups was determined using one-way ANOVA followed by the Student–Newman–Keuls test or Dunnett's T3 test.</p></sec><sec><title>Results</title><p>Compared with the PW rats, the Bic-NMW rats and the Sul-NMW rats had less urine net acid excretion (−1.51, 0.20 vs. 10.77, EQ/L), higher bone mineral density (442.50, 407.49 vs. 373.28, mg/mm<sup>3</sup>), growth cartilage width (271.83, 283.83 vs. 233.27, μm) and cortical trabecular area (9.33, 9.55 vs. 5.05, mm<sup>2</sup>), and smaller cortical marrow cavity area (5.40, 5.49 vs. 7.27, mm<sup>2</sup>) in the femur (<italic>P</italic> &lt; 0.05). Besides, the Bic-NMW rats had less serum calcium (2.53 vs. 2.68, mmol/L) and C-terminal cross-linked telopeptide of type-I collagen (1.35 vs. 1.93, ng/mL), and higher serum calcitonin (0.61 vs. 0.39, μg/L), femoral trabecular thickness (0.10 vs. 0.09, μm), bone volume/total volume (0.42 vs. 0.34, %), cortical bone area (15.91 vs. 12.80, mm<sup>2</sup>), and ultimate stress (35.12 vs. 29.32, MPa) (<italic>P</italic> &lt; 0.05). The Sul-NMW rats had more osteoclasts (22.50 vs. 11.54, cells/field) (<italic>P</italic> &lt; 0.05).</p></sec><sec><title>Conclusions</title><p>Drinking natural mineral water, especially bicarbonate-rich natural mineral water, is effective in improving bone health in young rats with metabolic acidosis. These benefits include maintaining bone mineral density, and improving bone microstructure and biomechanical properties <italic>via</italic> moderating metabolic acidosis.</p></sec>