A combination of prebiotic short- and long-chain inulin-type fructans enhances calcium absorption and bone mineralization in young adolescents
Am J Clin Nutr. 2005 Aug;82(2):471-6.
Abrams SA, Griffin IJ, Hawthorne KM, Liang L, Gunn SK, Darlington G, Ellis KJ.
Short-term studies in adolescents have generally shown an enhancement of calciumabsorption by inulin-typefructans (prebiotics). Results have been inconsistent; however, and no studies have been conducted to determine whether this effect persists with long-term use.
The objective was to assess the effects on calciumabsorption and bone mineral accretion after 8 wk and 1 y of supplementation with an inulin-type fructan.
Pubertal adolescents were randomly assigned to receive 8 g/d of a mixed short and long degree of polymerization inulin-type fructan product (fructan group) or maltodextrin placebo (control group). Bone mineral content and bone mineral density were measured before randomization and after 1 y. Calciumabsorption was measured with the use of stable isotopes at baseline and 8 wk and 1 y after supplementation. Polymorphisms of the Fok1 vitamin D receptor gene were determined.
Calciumabsorption was significantly greater in the fructan group than in the control group at 8 wk (difference: 8.5 +/- 1.6%; P 0.001) and at 1 y (difference: 5.9 +/- 2.8%; P = 0.04). An interaction with Fok1 genotype was present such that subjects with an ff genotype had the least initial response to fructan. After 1 y, the fructan group had a greater increment in both whole-body bone mineral content (difference: 35 +/- 16 g; P = 0.03) and whole-body bone mineral density (difference: 0.015 +/- 0.004 g/cm(2); P = 0.01) than did the control group.
Daily consumption of a combination of prebioticshort– and long-chaininulin-typefructans significantly increases calciumabsorption and enhancesbonemineralization during pubertal growth. Effects of dietary factors on calciumabsorption may be modulated by genetic factors, including specific vitamin D receptor gene polymorphisms.