Calcium Deficiency Decreases Bone Mass without Affecting Adiposity in Ovariectomized Rats Fed a High-Fat Diet.

Obesity induced by a high-fat (HF) diet increases bone resorption and/or decreases bone formation, resulting in reduced bone mass and strength in various animal models. Studies showed that Ca intake is a modifiable factor for osteoporosis and obesity. This study investigated whether Ca deficiency affects bone structure and adiposity in ovariectomized (OVX) rats fed a HF diet.

Time of day of exercise does not affect the beneficial effect of exercise on bone structure in older female rats.

Circadian clock genes are expressed in bone and biomarkers of bone resorption and formation exhibit diurnal patterns in animals and humans. Disruption of the diurnal rhythms may affect the balance of bone turnover and compromise the beneficial effects of exercise on bone. This study investigated whether the time of day of exercise alters bone metabolism in a rodent model.

Deficiency of PPARγ in Bone Marrow Stromal Cells Does not Prevent High-Fat Diet-Induced Bone Deterioration in Mice.

Background: Bone marrow osteoblasts and adipocytes are derived from a common mesenchymal stem cell and have a reciprocal relationship. Peroxisome proliferator-activated receptor gamma (PPARγ), a regulator for adipocyte differentiation, may be a potential target for reducing obesity and increasing bone mass.

Objectives: This study tested the hypothesis that bone-specific Pparg conditional knockout (cKO), via deletion of Pparg from bone marrow stromal cells (BMSC) using Osterix 1 (Osx1)-Cre, would prevent high-fat (HF) diet-induced bone deterioration in mice.

Decreasing the Ratio of Dietary Linoleic to α-Linolenic Acid from 10 to 4 by Changing Only the Former Does Not Prevent Adiposity or Bone Deterioration in Obese Mice.

Background: Linoleic acid (LA; 18:2n-6) has been considered to promote low-grade chronic inflammation and adiposity. Studies show adiposity and inflammation are inversely associated with bone mass.

Objectives: This study tested the hypothesis that decreasing the dietary ratio of LA to α-linolenic acid (ALA, 18:3n-3), while keeping ALA constant, mitigates high-fat diet (HF)-induced adiposity and bone loss.

Increasing Dietary Fish Oil Reduces Adiposity and Mitigates Bone Deterioration in Growing C57BL/6 Mice Fed a High-Fat Diet.

Background: Intake of total fat is linked to obesity and inversely associated with bone density in humans. Epidemiologic and animal studies show that long-chain n-3 (ω-3) PUFAs supplied as fish oil (FO) are beneficial to skeletal health.

Objective: This study tested the hypothesis that increasing dietary FO would decrease adiposity and improve bone-related outcomes in growing obese mice.

A High-Fat Diet Decreases Bone Mass in Growing Mice with Systemic Chronic Inflammation Induced by Low-Dose, Slow-Release Lipopolysaccharide Pellets.

Chronic inflammation is associated with increased bone resorption and is linked to osteopenia, or low bone mass. Obesity is also associated with low-grade chronic upregulation of inflammatory cytokines. This study investigated the effect of high-fat (HF) diet-induced obesity on bone structure changes in growing mice with existing systemic chronic inflammation induced by low-dose, slow-release lipopolysaccharide (LPS).

A high-fat diet increases body weight and circulating estradiol concentrations but does not improve bone structural properties in ovariectomized mice.

Bone health is influenced by body mass and estrogen. The objective of the study was to determine whether high-fat diet-induced obesity affects bone structure and alters markers of bone turnover in ovariectomized (OVX) mice. We hypothesized that a high-fat diet would increase body weight gain and serum estradiol levels in OVX mice but would not improve bone structural parameter in OVX mice.

Selenium deficiency decreases antioxidative capacity and is detrimental to bone microarchitecture in mice.

Selenium (Se), an essential mineral, plays a major role in cellular redox status and may have beneficial effects on bone health. The objective of this study was to determine whether Se deficiency affects redox status and bone microarchitecture in a mouse model. Thirty-three male C57BL/6J mice, 18 wk old, were randomly assigned to 3 groups.

Alpha-1 antitrypsin reduces ovariectomy-induced bone loss in mice.

Proinflammatory cytokines are primary mediators of bone loss in estrogen deficiency. This study determined whether alpha-1 antitrypsin (AAT), a multifunctional protein with proteinase inhibitor and anti-inflammatory activities, mitigates bone loss induced by estrogen deficiency. Mice were either sham-operated or ovariectomized and injected with either AAT or phosphate buffered saline (PBS).

High-fat diet decreases cancellous bone mass but has no effect on cortical bone mass in the tibia in mice.

Body mass has a positive effect on bone health. Whether mass derived from an obesity condition or excessive fat accumulation is beneficial to bone has not been established; neither have the mechanisms by which obesity affects bone metabolism. The aim of this study was to examine the effects of obesity on bone structure and osteoblastic expression of key markers involved in bone formation and resorption in a diet-induced obesity mouse model.

Determination of selenium bioavailability from wheat mill fractions in rats by using the slope-ratio assay and a modified torula yeast-based diet.

Selenium is an essential mineral micronutrient for animals, and significant evidence supports an association between supranutritional Se intake and a reduction in the incidence of some forms of cancer. Thus, supplemental Se intake may provide an avenue for reducing cancer incidence. However, an important issue to consider is the form of Se that should be provided in such a supplement, because the bioavailability and bioactivity of Se can vary dramatically depending on the chemical form in which it is delivered.

Selenium bioavailability from buckwheat bran in rats fed a modified AIN-93G torula yeast-based diet.

Selenium (Se) is an essential nutrient for humans and animals. The Se RDA for adult humans is 55 mug/d; however, dietary amounts as high as 200 mug/d in the highly available form of selenomethionine in yeast were shown to reduce the incidence of certain cancers. A number of natural foods contain relatively high amounts of Se; for the most part, however, the availability of food Se for absorption and utilization is unknown.

Bioavailability of selenium from meat and broccoli as determined by retention and distribution of 75Se.

The concentration of selenium (Se), an essential nutrient, is variable in foods, depending, in part, on how and where foods are produced; some foods accumulate substantial amounts of Se when produced on high-Se soils. The chemical form of Se also differs among foods. Broccoli is a Se-accumulating plant that contains many methylated forms of Se, and Se bioavailability from broccoli has been reported to be low.