Category Archives: Minerals

Selenium Protects Osteoblasts in Rats

Abstract

Selenium protects bone marrow stromal cells against hydrogen peroxide-induced inhibition of osteoblastic differentiation by suppressing oxidative stress and ERK signaling pathway.

Osteoporosis is a bone disease that leads to an increased risk of fracture. Oxidative stress may play a major role in the development of osteoporosis in part by inhibiting osteoblastic differentiation of bone marrow stromal cells (MSCs). Some evidence suggested that antioxidant selenium could prevent osteoporosis, but the underlying mechanism remains unclear. In this work, the effect of sodium selenite on H₂O₂-induced inhibition of osteoblastic differentiation of primary rat bone MSCs and the related mechanisms were examined. Pretreatment with selenite inhibited the adverse effect of H₂O₂ on osteoblastic differentiation of MSCs, based on alkaline phosphatase activity, gene expression of type I collagen and osteocalcin, and matrix mineralization. In addition, selenite pretreatment also suppressed the activation of extracellular signal-regulated kinase (ERK) induced by H₂O₂. The above effects were mediated by the antioxidant effect of selenite. Selenite enhanced the gene expression and activity of glutathione peroxidase, reversed the decreased total antioxidant capacity and reduced glutathione, and suppressed reactive oxygen species production and lipid peroxidation level in H₂O₂-treated MSCs. These results showed that selenite protected MSCs against H₂O₂-induced inhibition of osteoblastic differentiation through inhibiting oxidative stress and ERK activation, which provided, for the first time, the mechanistic explanation for the negative association of selenium status and risk of osteoporosis in terms of bone formation.

Liu H, Bian W, Liu S, Huang K
Biol Trace Elem Res Dec 2012
PMID: 22890880

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

Review: Inulin and FOS Mechanisms

Abstract

Inulin, oligofructose and bone health: experimental approaches and mechanisms.

Inulin-type fructans have been proposed to benefit mineral retention, thereby enhancing bone health. Many, but not all, experimental animal studies have shown increased mineral absorption by feeding non-digestible oligosaccharides. Possible reasons for inconsistencies are explored. A few studies have reported an enhanced bone mineral density or content. Bone health can be evaluated in chronic feeding studies with bone densitometry, bone breaking strength, bone mineral concentration and bone structure. Isotopic Ca tracers can be used to determine the point of metabolism affected by feeding a functional food ingredient. These methods and the effects of feeding inulin-type fructose are reviewed. Inulin-type fructans enhance Mg retention. Chicory long-chain inulin and oligofructose enhance femoral Ca content, bone mineral density and Ca retention through enhanced Ca absorption and suppressed bone turnover rates, but it is not bone-promoting under all conditions.

Weaver CM
Br. J. Nutr. Apr 2005
PMID: 15877902

Review: Inulin, Isoflavones, Calcium

Abstract

Inulin-type fructans and bone health: state of the art and perspectives in the management of osteoporosis.

If the primary role of diet is to provide sufficient nutrients to meet the metabolic requirements of an individual, there is an emerging rationale to support the hypothesis that, by modulating specific target functions in the body, it can help achieve optimal health. Regarding osteoporosis prevention, since Ca is most likely to be inadequate in terms of dietary intake, every strategy targeting an improvement in Ca absorption is very interesting. Actually, this process may be susceptible to manipulation by fermentable substrates. In this light, inulin-type fructans are very interesting, even if we need to gather more data targeting bone metabolism before health professionals can actively advocate their consumption to prevent senile osteoporosis. Besides targeting the prevention of postmenopausal osteoporosis, inulin-type fructans still remain a source for putative innovative dietary health intervention. Indeed, given in combination with isoflavones, they may have a potential for maintaining or improving the bone mass of human subjects, by modulating the bioavailability of phyto-oestrogens.

Coxam V
Br. J. Nutr. Apr 2005
PMID: 15877884

Review: Adding Calcium, Magnesium, Vitamin D, Vitamin K, Inulin, Protein, and Phytoestrogens to Foods

Abstract

Biomarkers of bone health appropriate for evaluating functional foods designed to reduce risk of osteoporosis.

Osteoporosis is a growing global problem. The health care costs and decreased productivity and quality of life are staggering. Much research is invested in life-style approaches to build peak bone mass during growth to prevent osteoporosis as well as to treat the disease in later life. Functional foods have enjoyed a niche in bone health. Foods fortified with Ca are most popular. Other bone nutrients such as vitamin D, Mg and vitamin K are sometimes added. Future products are likely to include enhancers of Ca absorption such as inulin or whey proteins. Dietary factors that reduce urinary Ca loss (plant proteins) or suppress bone resorption (possibly phyto-oestrogens) are also gaining attention. Methodologies for evaluating the effectiveness of functional foods on bone health include measures of bone quality such as bone densitometry or measures of Ca metabolism, particularly absorption. Biochemical markers for bone turnover are less satisfactory for diet-related effects. Use of a rare isotope, 41Ca, and accelerator mass spectrometry offers a new approach for assessing the ability of functional foods to suppress bone resorption.

Weaver CM, Liebman M
Br. J. Nutr. Nov 2002
PMID: 12495464

Inulin Increases Whole-Body Bone Minerals in Rats

Abstract

Dietary chicory inulin increases whole-body bone mineral density in growing male rats.

Chicory inulin is a natural linear fructan that is not digested in the upper part of the gastrointestinal tract but is fermented in the cecocolon. It enhances calcium absorption in rats and improves femur and tibia mineral contents in gastrectomized or ovariectomized rats. We studied the effect of inulin (0, 5 and 10 g/100 g diet) on whole-body bone mineral content (WBBMC), whole-body bone area (WBBA) and whole-body bone mineral density (WBBMD) in live, growing male rats fed diets containing 0.2, 0.5 or 1 g Ca/100 g. Three experiments, each corresponding to one of the different dietary Ca concentrations, were performed using male Wistar rats (n = 108; 4 wk old). WBBMC was measured by dual-energy X-ray absorptiometry every 4 wk up to wk 22. Inulin increased WBBMC (P < 0.05) and WBBMD (P < 0.001) significantly but not WBBA at all ages and all dietary calcium concentrations. This is the first report to demonstrate that chicory inulin not only increases calcium absorption but also increases mineral parameters in whole-body bones.

Roberfroid MB, Cumps J, Devogelaer JP
J. Nutr. Dec 2002
PMID: 12468594 | Free Full Text

FOS Most Effective with High Calcium in Mice

Abstract

Effect of oligofructose or dietary calcium on repeated calcium and phosphorus balances, bone mineralization and trabecular structure in ovariectomized rats.

We investigated the effects of dietary oligofructose and Ca on bone structure in ovariectomized rats, using microradiography and histomorphometry. Ninety-six animals were allocated to seven experimental groups: G1, sham-operated; G2-G7, ovariectomized. Semi-purified diets containing 5 g Ca/kg (recommended content) without oligofructose (G1, G2) or with 25, 50 or 100 g oligofructose/kg (G3, G4, G5) or 10 g Ca/kg (high content) without oligofructose (G6) or with 50 g oligofructose/kg (G7) were fed for 16 weeks. At the recommended level of Ca, high oligofructose (G5) increased femur mineral levels in ovariectomized rats, while medium oligofructose did so at high Ca. Increasing Ca in the absence of oligofructose did not increase femur mineral content. Trabecular bone area (%) analysed in the tibia was 10.3 (sem 1.2) (G1), 7.7 (sem 0.6) (G2), 9.3 (sem 0.7) (G3), 9.4 (sem 1.0) (G4), 9.5 (sem 0.7) (G5), 10.2 (sem 0.8) (G6), and 12.6 (sem 0.8) (G7). At the recommended level of Ca, 25 g oligofructose/kg prevented loss of trabecular area due to increased trabecular thickness, while 50 or 100 g oligofructose/kg increased trabecular perimeter. At high Ca, oligofructose prevented loss of bone area due to increased trabecular number but similar thickness (G7 v. G6). When Ca was raised in the presence of oligofructose (G7), trabecular area and cortical thickness were highest, while loss of trabecular connectivity was lowest of all groups. At the same time, lumbar vertebra Ca was higher; 44.0 (sem 0.8) (G7) compared with 41.6 (sem 0.8) (G2), 41.4 (sem 0.7) (G4), and 40.5 (sem 1.0) mg (G6). We conclude that ovariectomy-induced loss of bone structure in the tibia was prevented but with different trabecular architecture, depending on whether dietary Ca was increased, oligofructose was incorporated, or both. Oligofructose was most effective when dietary Ca was high.

Scholz-Ahrens KE, Açil Y, Schrezenmeir J
Br. J. Nutr. Oct 2002
PMID: 12323086

Calcium and Exercise in Rats

Abstract

Short- and long-term effects of calcium and exercise on bone mineral density in ovariectomized rats.

At the level of prevention of bone mineral loss produced by ovariectomy, the aim of the present study was to determine the effect produced by supplementation of Ca in the diet and a moderate exercise programme (treadmill), simultaneously or separately, in ovariectomized rats, an experimental model of postmenopausal bone loss. Female Wistar rats (n 110, 15 weeks old) were divided into five groups: (1) OVX, rats ovariectomized at 15 weeks of age, fed a standard diet; (2) SHAM, rats sham operated at 15 weeks of age, fed a standard diet; (3) OVX-EX, ovariectomized rats, fed a standard diet and performing the established exercise programme; (4) OVX-Ca, ovariectomized rats fed a diet supplemented with Ca; (5) OVX-EXCa, ovariectomized rats with the exercise programme and diet supplemented with Ca. The different treatments were initiated 1 week after ovariectomy and were continued for 13 weeks for subgroup 1 and 28 weeks for subgroup 2, to look at the interaction of age and time passed from ovariectomy on the treatments. Bone mineral density (BMD) was determined, at the end of the study, in the lumbar spine (L2, L3 and L4) and in the left femur using a densitometer. Bone turnover was also estimated at the end of the study, measuring the serum formation marker total alkaline phosphatase (AP) and the resorption marker serum tartrate-resistant acid phosphatase (TRAP). As expected, OVX rats showed a significant decrease (P<0.05) in BMD, more pronounced in subgroup 2, and a significant increase in AP and TRAP with regard to their respective SHAM group. The simultaneous treatment with Ca and exercise produced the best effects on lumbar and femoral BMD of ovariectomized rats, partially avoiding bone loss produced by ovariectomy, although it was not able to fully maintain BMD levels of intact animals. This combined treatment produced a significant increase in AP, both in subgroups 1 and 2, and a decrease in TRAP in subgroup 1, with regard to OVX group. The exercise treatment alone was able to produce an increase in BMD with regard to OVX group only in subgroup 1 of rats (younger animals and less time from ovariectomy), but not in subgroup 2. In agreement with this, there was an increase of AP in both subgroups, lower than that observed in animals submitted to exercise plus Ca supplement, and a decrease of TRAP in subgroup 1, without significant changes in this marker in the older rats. Ca treatment did not produce any significant effect on BMD in OVX rats in both subgroups of animals, showing a decrease of AP and TRAP levels in the younger animals with no significant variations in markers of bone remodelling in the older female rats compared with their respective OVX group.

Gala J, Díaz-Curiel M, de la Piedra C, Calero J
Br. J. Nutr. Oct 2001
PMID: 11591240

I don’t know what to make of this.