Gene-dietary fat interaction, bone mineral density and bone speed of sound in children: a twin study in China

A comparative study between olive oil and corn oil on oxidative metabolism

Fats are an important part of diet, but not all lipids have the same structure and chemical properties. Unsaturated fatty acids have one or more double bonds in their structure and can be monounsaturated or polyunsaturated, respectively. Most vegetable oils, such as olive oil and corn oil, contain significant amounts of these fatty acids. The presence of double bonds in the molecule of a fatty acid constitutes vulnerable sites for oxidation reactions generating lipid peroxides, potentially toxic compounds that can cause cellular damage. In response to this oxidative damage, aerobic organisms have intracellular enzymatic antioxidant defense mechanisms. The aim of the present investigation was to study comparatively the effects of control liquid diets, of a defined composition, containing olive oil or corn oil as a lipid source respectively of monounsaturated and polyunsaturated fatty acids, on the oxidative metabolism of rats. Rats were divided into three groups which received a control animal feed diet (A.F.), olive oil liquid diet (O.O) and corn oil liquid diet (C.O) for 30 days. It was observed that the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), increased in the liver and white fat tissue of rats fed with olive oil when compared to the corn oil group. However, in brown fat tissue and blood cells, the enzyme activities showed a tendency to decrease in the olive oil group. In addition, the effect of olive oil and corn oil on several glucose metabolism parameters (pyruvate, lactate, LDH, acetoacetate and beta-hydroxybutyrate) showed that corn oil impairs to a greater extent the cellular metabolism. All these results helped in concluding that some body tissues are more adversely affected than others by the administration of corn oil or olive oil, and their antioxidant defenses and cellular metabolism respond differently too.

Association of serum 25-hydroxyvitamin D status with bone mineral density in 0-7 year old children

OBJECTIVE

To describe the status of serum 25-hydoxyvitamin D [25(OH)D] concentrations and identify the relationship between 25(OH)D and bone mineral density (BMD). In an effort to explore the appropriate definition of vitamin D (VD) deficiency in 0-7 year old children.

RESULTS

The median serum 25(OH)D concentrations was 62.9 nmol/L and 28.9% of the children had a low 25(OH)D (< 50 nmol/L). And a linear relation between 25(OH)D concentrations and BMD was surveyed (r = 0.144 , P < 0.001). After adjusting for the confounders, serum 25(OH)D was positively associated with BMD (β = 172.0, 95%CI = 142.8-201.2, P < 0.001), and low 25(OH)D (< 75 nmol/L) had a high stake for low BMD (OR = 1.424, 95%CI = 1.145-1.769, P = 0.001). Additionally, there was a nonlinear relation between 25(OH)D and low BMD, and a critical value for 25(OH)D of 75 nmol/L appeared for low BMD. The prevalence of low BMD was 14.1% in children with 25(OH)D ≥ 75 nmol/L, much lower than that of the concentrations between 50-75 nmol/L and < 50 nmol/L.

MATERIALS AND METHODS

A total of 4,846 children 0-7 years old were recruited in Jiangsu Province, China. BMD and serum 25(OH)D concentrations were determined by quantitative ultrasound and enzyme-linked immunosorbent assay, respectively. Linear regression and logistic regression analyses were used to assess the association of 25(OH)D concentrations with BMD.

CONCLUSIONS

Serum 25(OH)D concentrations was related with BMD and 25(OH)D concentrations < 75 nmol/L might be a more appropriate definition of VD deficiency in 0-7 year old children.