Effect of phytase supplementation on zinc, iron and calcium status in rats fed with diet containing Iranian high phytate bread [Sangak]

Restricted mineral bioavailability of minerals in Iranian breads due to high levels of phytic acid has been reported for more than 50 years. Bread intakes still provide over one-third of the food energy through out the country. Hence improving bread mineral bioavailability can play an important role in decreasing the prevalence of many mineral deficiencies. The aim of this study was to assess the effect of phytase supplementation on blood, liver and bone zinc, blood and liver iron and femur bone calcium in growing Wistar male rats, fed a diet containing high phytate Iranian bread [Sangak]. Thirty weaning Wistar rats were assigned to the phytase [Aspergillus niger] or the control group for 6 weeks. The diet was designed based on Iranian food patterns and 34.2% of energy was supplied from Sangak bread with high amount of phytic acid. Feed intakes, weight gain, liver and femur bone weight did not differ between the groups. Blood zinc was higher in the phytase group [p=0.03], indicating the positive effect of phytase supplementation on blood zinc levels, independent of the growth process. Other variables did not show any differences between groups. We conclude that the addition of high phytate Iranian bread phytase to the diet can improve blood zinc status in growing rats

[Effect of calcium supplementation on the lipid profiles of overweight or obese women: a double blind randomized clinical trial]

There is some evidence suggesting a probable beneficial effect of calcium intake on serum lipid profile. The objective of this study was to determine the effect of 1000 mg calcium supplementation for 30 days on serum lipid profiles in overweight or obese women. A double blind randomized clinical trial was conducted in 44 overweight or obese adult women [Body mass index >/= 25 kg/m2, age: 25 +/- 6 years] randomly assigned to the calcium [receiving 1000 mg elemental calcium per day] or the placebo group. Serum lipids, lipoproteins and apolipoproteins including triglycerides, total cholesterol, HDL cholesterol, ApoA-I and Apo B were obtained at baseline and after the intervention period. Freidwald equation was used to calculate LDL cholesterol and VLDL cholesterol was calculated from TG divided by 5. Dietary calcium and energy intake were estimated using 24 hour recall for 3 days. Statistical analyses were performed using SPSS software [version 9]. P values < 0.05 were considered as statistically significant. No significant differences were observed in dietary, anthropometric and serum variables between the two groups at the baseline. Although all serum total-, LDL cholesterol and triglycerides tended to increase in both study groups, total cholesterol elevation was only significant in the placebo group [p=0.01], and triglyceride and VLDL cholesterol only showed significant increase in the calcium group [p=0.03]. LDL cholesterol elevation was significant in both groups [p<0.05] HDL cholesterol decreased significantly in both groups [p<0.01]. Apolipoproteins did not change significantly in the study groups. No significant differences were observed in serum variables between groups after intervention. In the present study short term calcium supplementation in overweight or obese women's showed no beneficial effect on lipid profiles. Because of the limited studies available, further studies are recommended

[Validation study of height-weight difference index [HWDI] for screening underweight and obesity and obesity status in Tehranian adults]

Body mass index [BMI] is the most common index for assessing weight status of adults, at both individual and population levels. However, calculating BMI without an instrument is quite difficult and time consuming. The objective of this study was to test whether the proposed new and simple height weight difference index [HWDI] is valid for screening different weight status. The data, obtained from adult participants of Tehran lipid and glucose study [TLGS] were used for this cross-sectional study. Height and weight of 10723 [4555 male, 6168 female] 18 to 70 year old subjects were used for calculating BMI [weight in kg, divided by height squared in meters] and HWDI [height in cm, minus weight in kg]. Linear regression was used to determine the relationship between BMI and HWDI, and Kappa statistic was used to test the agreement between the indices. There was an inverse strong relationship between BMI and HWDI [r=-0.98, p<0.0001]. Cut-off points for different weight status, according to HWDI, based on current BMI references, were calculated by the prediction formula: HWDI = 163.4-2.67 BMI. HWDI had high sensitivity and specificity for obesity at all levels, and Kappa test, showed an excellent agreement between the two indices. Specificity of HWDI was high for total thin subjects, but sensitivity and Kappa for grades 1 and 2 thinness was low. Although a high sensitivity was observed for grade 3 thinness, Kappa was low for the grade 3 thinness. While considering all thin subjects all together, there was a high sensitivity and specificity, and a good agreement. HWDI can be used as an applied and simple index for diagnosis of different grades of obesity from normal status. Although the index can not determine different grades of thinness, but is useful to diagnose the status as a whole