Bone Abstracts

Dietary Ca insufficiency is a common finding, independently of socio-economic status. A low Ca intake (CaI) increases bone turnover leading to bone loss. This effect becomes more important during estrogen withdrawing. We previously found that a mixture of galactooligosaccharides (GOS) and fructooligosaccharides (FOS) enhances Ca and P absorption (Abs), being a suitable tool to optimize its bioavailability and consequently bone health. The present study evaluated the effect of feeding a low Ca diet containing a mixture of GOS/FOS (9:1) on Ca and P Abs and bone retention in female Wistar osteopenic rats. Rats were ovariectomized (OVX) or SHAM operated and remained untreated during a 45 day-period. Then, they were randomly assigned to received one of the following diets prepared according to the American Institute of Nutrition formulation for maintenance (AIN′93): AIN′93 (C) or AIN′93+2.5% GOS/FOS® (P) containing 0.5% or 0.3% of Ca (groups: C0.5%, C0.3%, P0.5% and P0.3%, respectively) for an additional period of 45-days. Dietary consumption was evaluated 3 times per week. Body weight (BW) was recorded weekly. Ca and P Abs percentage (%) were determined at the beginning and during the last 3 days of the experience. At the end of the study (tf) CTX (ng/ml): bone alkaline fosfatase (BALP) (IU/l), total skeleton bone mineral content/BW (tsBMC) (g/100 gBW) and density (tsBMD) (mg/cm²), tibia and spine BMDs and Growth plate cartilage height (GPC.Th) (μm), were evaluated. Results at tf (mean±SD): C0.5%; C0.3%; P0.5%; P0.3%, respectively (Different letters indicate a P<0.05) BW (g): 329±41; 327±31; 326±45; 321±42; Food intake (g/d): 22.6±4.9; 19.719.7.8; 22.9±0.6; 20.7±1.7; Ca Abs (%): 69.1±3.1d; 76.2±2.6c; 83.6±4.6b; 89.5±3.8a; P Abs (%): 73.1±2.0b; 71.5±1.1b; 84.8±2.4a; 83.3±2.1a; Caecal pH: 7.15±0.10a; 7.18±0.20a; 6.71±0.20b; 6.67±0.20b; CTX38.7±5.4a; 52.2±5.6b; 30.0±11.0a; 41.1±8.8a; BALP: 50±4; 49.6±6; 502417; 49±6; tsBMC: 2.01±0.13b; 1.78±0.14c; 2.45±0.10a; 2.06±0.24b; tsBMD: 294±7; 286±6; 295±2; 289±2; Tibia BMD: 247±10b; 231±10c; 256±7a; 241±10b; spine BMD: 229±13b; 2419±12c; 241±14a; 228±14b; GPC.Th: 246±27a; 219±17b; 252±20a; 245±22a.

Conclusion: The consumption of the GOS/FOS® mixture added to a low Ca diet enhanced Ca and P Abs % increasing bone mass and trabecular bone density, evidencing its usefulness to give an extra amount of Ca and P for maintaining bone health. Thanks to ® N.V.Nutricia for the mixture. Grants: PIP 11220100100004 and UBACyT 20020130100091BA.