Inulin Has No Effect on Bone Density in Young Rats

Abstract

Dietary long-chain inulin reduces abdominal fat but has no effect on bone density in growing female rats.

New strategies to improve Ca absorption and bone health are needed to address the current state of osteoporosis prevention and management. Inulin-type fructans have shown great promise as a dietary intervention strategy, but have not yet been tested in a young female model. Our objective was to investigate the effect of long chain (LC) inulin on bone mineralization and density in growing, female rats, as well as the quality of growth. Weanling Sprague-Dawley rats were assigned to inulin or cellulose treatments for either 4 or 8 weeks. Growth was measured weekly and quality of growth assessed using fat pad weights and dual-energy X-ray absorptiometry (DXA). Whole body (WB) and selected regions were analysed for bone mineral density (BMD) and body composition by DXA. Serum markers of bone turnover were assessed by enzyme-linked immunosorbent assays. Ca and P concentrations were determined in excised femurs by inductively coupled plasma spectrometry. Feeding inulin resulted in 4 % higher femoral weight (adjusted for body weight) and 6 % less feed intake. Inulin did not affect WB or regional BMD, but was associated with a 28 % lower parametrial fat pad mass, 21 % less WB fat mass and 5 % less WB mass. In summary, LC-inulin lowered body fat mass, without consequence to bone density in growing female rats.

Jamieson JA, Ryz NR, Taylor CG, Weiler HA
Br. J. Nutr. Aug 2008
PMID: 18279560

Review: Calcium, Vitamin D, K, Phytoestrogens

Abstract

Diet, nutrition, and bone health.

Osteoporosis is a debilitating disease that affects many older people. Fragility fractures are the hallmark of osteoporosis. Although nutrition is only 1 of many factors that influence bone mass and fragility fractures, there is an urgent need to develop and implement nutritional approaches and policies for the prevention and treatment of osteoporosis that could, with time, offer a foundation for population-based preventive strategies. However, to develop efficient and precocious strategies in the prevention of osteoporosis, it is important to determine which modifiable factors, especially nutritional factors, are able to improve bone health throughout life. There are potentially numerous nutrients and dietary components that can influence bone health, and these range from the macronutrients to micronutrients as well as bioactive food ingredients. The evidence-base to support the role of nutrients and food components in bone health ranges from very firm to scant, depending on the nutrient/component. This article initially overviews osteoporosis, including its definition, etiology, and incidence, and then provides some information on possible dietary strategies for optimizing bone health and preventing osteoporosis. The potential benefits of calcium, vitamin D, vitamin K(1), phytoestrogens, and nondigestible oligosaccharides are briefly discussed, with particular emphasis on the evidence base for their benefits to bone. It also briefly considers some of the recent findings that highlight the importance of some dietary factors for bone health in childhood and adolescence.

Cashman KD
J. Nutr. Nov 2007
PMID: 17951494 | Free Full Text

Equol is Bone Sparing, Like Isoflavones in Rats

Abstract

Modulation of soy isoflavones bioavailability and subsequent effects on bone health in ovariectomized rats: the case for equol.

Soy products are of particular interest because of their potential health benefits in a range of hormonal conditions, such as osteoporosis, due to their high content in phytoestrogens. Because equol, the main metabolite from soy isoflavones, is thought to be powerful, the present study was designated to evaluate the bone-sparing effects of equol by either providing the molecule through the diet or by eliciting its endogenous production by modulating intestinal microflora by short-chain fructooligosaccharides (sc-FOS) or live microbial (Lactobacillus casei) together with daidzein, its precursor.
A comparison with daidzein and genistein was also performed. Rats (3 months old) were ovariectomised (OVX) or sham-operated (SH). Ovariectomised rats were randomly assigned to six experimental diets for 3 months: a control diet (OVX), the control diet supplemented with either genistein (G), or daidzein (D), or equol (E) at the level of 10 microg/g body weight/d. The remaining OVX rats were given daidzein at the dose of 10 mug/g body weight/d, simultaneously with short-chain FOS (Actilight, Beghin-Meiji) (D+FOS) or Lactobacillus casei (Actimel, Danone) (D+L). The SH rats were given the same control diet as OVX.
Genistein, daidzein or equol exhibited a bone sparing effect. Indeed, total femoral bone mineral density (BMD) was significantly enhanced (compared to that of OVX rats), as was the metaphyseal compartment. Bone strength was improved by E consumption, but not by genistein or daidzein given alone. As far as the FOS diet is concerned, the addition of prebiotics significantly raised efficiency of the daidzein protective effect on both femoral BMD and mechanical properties. The effects of lactobacillus were similar, except that the increase in metaphyseal-BMD was not significant.
In conclusion, long-term equol consumption, like genistein and daidzein, in the ovariectomized rat, provides bone sparing effects. Adding indigestible sugars, such as FOS or live microbial as L. casei, in the diet significantly improves daidzein protective effects on the skeleton.

Mathey J, Mardon J, Fokialakis N, Puel C…
Osteoporos Int May 2007
PMID: 17333448

FOS-Inulin Mix Increases Osteocalcin in Women

Abstract

Effects of oligofructose-enriched inulin on intestinal absorption of calcium and magnesium and bone turnover markers in postmenopausal women.

Deficiency of oestrogen at menopause decreases intestinal Ca absorption, contributing to a negative Ca balance and bone loss. Mg deficiency has also been associated with bone loss. The purpose of the present investigation was to test the hypothesis that treatment with a spray-dried mixture of chicory oligofructose and long-chain inulin (Synergy1; SYN1) would increase the absorption of both Ca and Mg and alter markers of bone turnover. Fifteen postmenopausal women (72.2 (SD 6.4) years) were treated with SYN1 or placebo for 6 weeks using a double-blind, placebo-controlled, cross-over design. Fractional Ca and Mg absorption were measured using dual-tracer stable isotopes before and after treatment. Bone turnover markers were measured at baseline, 3 and 6 weeks. Fractional absorption of Ca and Mg increased following SYN1 compared with placebo (P < 0.05). Bone resorption (by urinary deoxypyridinoline cross-links) was greater than baseline at 6 weeks of active treatment (P < 0.05). Bone formation (by serum osteocalcin) showed an upward trend at 3 weeks and an increase following 6 weeks of SYN1 (P < 0.05). Closer examination revealed a variation in response, with two-thirds of the subjects showing increased absorption with SYN1. Post hoc analyses demonstrated that positive responders had significantly lower lumbar spine bone mineral density than non-responders (dual X-ray absorptiometry 0.887 +/- 0.102 v. 1.104 +/- 0.121 g/cm2; P < 0.01), and changes in bone turnover markers occurred only in responders. These results suggest that 6 weeks of SYN1 can improve mineral absorption and impact markers of bone turnover in postmenopausal women. Further research is needed to determine why a greater response was found in women with lower initial spine bone mineral density.

Holloway L, Moynihan S, Abrams SA, Kent K…
Br. J. Nutr. Feb 2007
PMID: 17298707

Review: FOS Preventive Effects on Bone [Japanese]

Abstract

Prevention of osteoporosis by foods and dietary supplements. The effect of fructooligosaccharides (FOS) on the calcium absorption and bone.

Fructooligosaccharides (FOS) are well known as prebiotics which improve intestinal microflaura. FOS also have increasing effect on the intestinal absorption of calcium (Ca), magnesium (Mg) and iron. These effects were inspected by many animal experiments and then by human studies. Especially, FOS clearly prevent the decrease of bone mineral density by gastrectomy in rats. In this report, we mainly explain the preventive effect of FOS on the bone of gastrectomized rats and introduce relationship between another food ingredient or exercise.

Ohta A
Clin Calcium Oct 2006
PMID: 17012821

FOS + Soy Effects Additive For Some Parameters in Rats

Abstract

The effects of fructo-oligosaccharides in combination with soy protein on bone in osteopenic ovariectomized rats.

The intestinal microflora is important in rendering soy isoflavones bioavailable by facilitating their conversion to equol. Hence, substances that can modulate the intestinal microflora could affect the bioavailability of isoflavones. In this study, we examined the effects of fructo-oligosaccharides (FOS), a prebiotic, on enhancing the effects of soy isoflavones on bone in ovariectomized osteopenic female rats.
Sixty-three 9-month-old female Sprague-Dawley rats were either sham-operated (Sham; one group) or ovariectomized (Ovx; four groups) and were fed a control diet for 3 months to induce bone loss. After bone loss was confirmed via dual-energy x-ray absorptiometry, rats were placed on dietary treatment for 4 months. The Sham and one Ovx group received a control diet, and the remaining Ovx groups received either a soy protein-based diet (Soy), a FOS-supplemented diet (FOS), or a soy protein-based and FOS-supplemented diet (Soy+FOS). Before the termination of the study, whole-body bone mineral density (BMD) and bone mineral content (BMC) were assessed under anesthesia. Immediately after euthanasia, bone specimens were collected for the assessments of BMD, BMC, and biomechanical and microarchitectural properties.
Whole-body BMD values were significantly higher in FOS and Soy+FOS groups compared with Ovx controls. The tibial BMC increased by 10%, 6%, and 4% in Soy, FOS, and Soy+FOS groups, respectively, compared to the Ovx control group. FOS and FOS+Soy treatments had the most pronounced effects in enhancing lumbar BMC and BMD. The FOS+Soy combination effectively improved tibial microarchitectural properties by enhancing trabecular number and lowering trabecular separation compared with Ovx controls. The effects of dietary treatments on lumbar microarchitectural properties were minimal and biomechanical properties of the femur were not affected by any of the dietary treatments.
Our findings suggest that, although incorporation of either soy or FOS in the diet of Ovx rats can improve BMD of the whole body, tibiae, and lumbar vertebrae, their combination had no any additive effects. However, in terms of microarchitecture, the combination of soy and FOS had a greater effect in reversing the loss of certain microarchitectural parameters such as tibial trabecular number, separation, and thickness.

Devareddy L, Khalil DA, Korlagunta K, Hooshmand S…
Menopause
PMID: 16837891

Review: Prebiotics in Adolescents

Abstract

A prebiotic substance persistently enhances intestinal calcium absorption and increases bone mineralization in young adolescents.

A number of short-term (9 days to 5 weeks) studies have reported that non-digestible. oligosaccharides enhance intestinal calcium absorption. Recent interesting data from an intervention trial in adolescents (9-13 years of age) suggest that a non-digestible oligosaccharide can persistently stimulate calcium absorption over 12 months and can also enhance bone mineralization during pubertal growth.

Cashman KD
Nutr. Rev. Apr 2006
PMID: 16673754

FOS Helps Dentin Formation in Rats

Abstract

Fructooligosaccharide consumption improves the decreased dentin formation and mandibular defects following gastrectomy in rats.

We examined the effects of fructooligosaccharides (FOS) consumption on gastrectomy-evoked osteopenia and disorders of dentin formation in rats.
Male Sprague-Dawley rats (n = 28, 35-day old) were equally divided into two groups; sham-operated and gastrectomized, and sham-operation or total gastrectomy was performed. Four weeks after each surgery, the rats were divided into two sub-groups (n = 7 each); with or without 7.5% FOS-feeding for 6 weeks. Backscattered electron images of the mandibular sections were taken to calculate trabecular bone area, cortical bone area and total scan area. Thereafter, the dentin formation rate in maxilla were calculated using a fluorescent microscope.
Trabecular bone area and cortical bone area in GX rats were markedly decreased. FOS-feeding significantly counteracted this reduction, but not to the level seen in sham-operated rats. Total scan area in gastrectomized groups was significantly decreased. The dentin formation rate was not statistically different among the groups, except the gastrectomized group.
These results suggest that FOS consumption partially restored osteopenia and almost completely restored the reduction in dentin formation following gastrectomy in rats.

Morohashi T, Sano T, Sakai N, Yamada S
Oral Dis Nov 2005
PMID: 16269026

COS, Like FOS, Increases Calcium Retention, Bone Density and Strength in Rats

Abstract

Effect of chitooligosaccharides on calcium bioavailability and bone strength in ovariectomized rats.

Chitosan polymer with deacetylation degree of 93% was hydrolyzed with an endo-type chitosanase (35,000 U/g protein) with substrate to enzyme ratio of 1 to 1.5 for 18 h in a batch reactor, and then the resultant hydrolysates were fractionated into four different molecular weights using an ultrafiltration (UF) membrane reactor system. An in vitro study elucidated that four kinds of chitooligosaccharides (COSs) could efficiently inhibit the formation of insoluble calcium salts in the neutral pH. In vivo effects of COSs on Ca bioavailability were further studied in the osteoporosis modeling rats induced by ovariectomy and concurrent low calcium intake. During the experimental period corresponding to the menopause with the osteoporosis disease, calcium retention was increased and bone turnover was decreased by COS IV supplementation in the ovariectomized (OVX) rats. After the low Ca diet, COS IV diet including both normal level of calcium and vitamin D significantly decreased calcium loss in feces and increased calcium retention compared to the control diet. The levels of femoral total calcium, bone mineral density (BMD), and femoral strength were also significantly increased by the COS IV diet in a similar level to those of CPP diet group. In the present study, the results proved the beneficial effects of low molecular chitooligosaccharide (COS IV) in preventing negative mineral balance.

Jung WK, Moon SH, Kim SK
Life Sci. Jan 2006
PMID: 16137703

Inulin Increases Calcium Absorption and Bone Mineralization in Adolescents

Abstract

A combination of prebiotic short- and long-chain inulin-type fructans enhances calcium absorption and bone mineralization in young adolescents.

Short-term studies in adolescents have generally shown an enhancement of calcium absorption by inulin-type fructans (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 calcium absorption 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. Calcium absorption 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.
Calcium absorption 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 prebiotic short- and long-chain inulin-type fructans significantly increases calcium absorption and enhances bone mineralization during pubertal growth. Effects of dietary factors on calcium absorption may be modulated by genetic factors, including specific vitamin D receptor gene polymorphisms.

Abrams SA, Griffin IJ, Hawthorne KM, Liang L…
Am. J. Clin. Nutr. Aug 2005
PMID: 16087995 | Free Full Text