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Effects of fructans-containing yacon ( Smallanthus sonchifolius Poepp & Endl.) flour on caecum mucosal morphometry, calcium and magnesium balance, and bone calcium retention in growing rats

Yacon roots have been considered a functional food due to the high levels of fructans they contains. In the present study, Ca and Mg balance, bone mass and strength, and caecum mucosal morphometry were evaluated. Growing male Wistar rats (n 24) were fed ad libitum control diets or diets supplemented with yacon flour (5 or 7.5 % fructooligosaccharides) for 27 d. Mineral balance was evaluated in three periods of 5 d (starting on the 4th, 10th and 16th days). After the rats were killled, the bones were removed and bone mineral density was measured. Ca analyses were performed on left femurs and tibias and biomechanical testing on right femurs. The caecum was removed and tissue samples were collected for histological analysis. Caecal histology changed noticeably in rats fed yacon flour: there was an increase in the depth and number of total and bifurcated crypts as well. Yacon flour consumption significantly (P < 0.05) resulted in a positive Ca and Mg balance, leading to higher values of bone mineral retention and biomechanical properties (peak load and stiffness) when compared to the control group. The positive effects on mineral intestinal absorption, bone mass and biomechanical properties showed an important role of yacon roots in the maintenance of healthy bones. The increased number of bifurcating crypts might be related to the higher mineral absorption caused by the enlargement of the absorbing surface in the large intestine of the animals.

Effects of dietary lipid composition and inulin-type fructans on mineral bioavailability in growing rats

OBJECTIVE This study reports the effects of feeding with a combination of inulin-type fructans (ITF) and fish oil (FO) on mineral absorption and bioavailability as part of a semipurified diet offered to rats. METHODS Male Wistar rats (n = 24) were fed a 15% lipid diet (soybean oil [SO] or a 1:0.3 fish:soybean oil mixture [FSO]) and diets containing the same sources of lipids supplemented with 10% ITF (Raftilose Synergy 1) ad libitum for 15 d. Feces and urine were collected for mineral analyses during the last 5 d of the test period. Fatty acid composition was determined in liver and cecal mucosa homogenates. Liver and bone mineral analyses were performed by atomic absorption spectrophotometry. Bone biomechanical analyses were evaluated by a 3-point bending test. RESULTS Compared with the controls, ITF-fed rats had enlarged ceca and a significant decrease in cecal content pH (P < 0.001). The apparent mineral absorption was improved in these rats, and this effect was enhanced by dietary combination with FO for all minerals except for magnesium. Addition of ITF to the diet resulted in higher bone mineral content (calcium and zinc) and bone strength, but increased bone mineral content was only statistically significant in FO-fed animals. A decrease in liver iron stores (P = 0.015) was observed in rats fed FO, considering that ITF consumption returned to levels comparable to the SO control group. CONCLUSION These findings confirm the positive influence of ITF on mineral bioavailability, which was potentiated by addition of FO to the diet.

Influence of magnesium status and magnesium intake on the blood glucose control in patients with type 2 diabetes

BACKGROUND & AIMS This study was undertaken to assess magnesium intake and magnesium status in patients with type 2 diabetes, and to identify the parameters that best predict alterations in fasting glucose and plasma magnesium. METHODS A cross-sectional study was carried out in patients with type 2 diabetes (n = 51; 53.6 ± 10.5 y) selected within the inclusion factors, at the University Hospital Onofre Lopes. Magnesium intake was assessed by three 24-h recalls. Urine, plasma and erythrocytes magnesium, fasting and 2-h postprandial glucose, HbA1, microalbuminuria, proteinuria, and serum and urine creatinine were measured. RESULTS Mean magnesium intake (9.37 ± 1.76 mmol/d), urine magnesium (2.80 ± 1.51 mmol/d), plasma magnesium (0.71 ± 0.08 mmol/L) and erythrocyte magnesium (1.92 ± 0.23 mmol/L) levels were low. Seventy-seven percent of participants presented one or more magnesium status parameters below the cut-off points of 3.00 mmol/L for urine, 0.75 mmol/L for plasma and 1.65 mmol/L for erythrocytes. Subjects presented poor blood glucose control with fasting glucose of 8.1 ± 3.7 mmol/L, 2-h postprandial glucose of 11.1 ± 5.1 mmol/L, and HbA1 of 11.4 ± 3.0%. The parameters that influenced fasting glucose were urine, plasma and dietary magnesium, while plasma magnesium was influenced by creatinine clearance. CONCLUSIONS Magnesium status was influenced by kidney depuration and was altered in patients with type 2 diabetes, and magnesium showed to play an important role in blood glucose control.

Extrusion and iron bioavailability in chickpea (Cicer arietinum L.).

The eAect of extrusion cooking (14% moisture and 130C processing temperature) and of home-cooking on chickpea iron bioavailability was studied by the hemoglobin regeneration method in anemic rats. The iron pool was calculated from hemoglobin concentration and animal weight, and iron bioavailability from the relationship between iron pool gain ( pool) and mg of ingested iron. Iron bioavailability relative to ferrous sulfate was calculated by the following equation: Y=63.989 e ˇ0.0458X [Y= % absorbed; X=ingested Fe (mg)] on the basis of the results of control groups. The results showed that there was no significant diAerence between groups (extruded and cooked) in terms of mean percentage of iron bioavailability relative to Fe2SO4. We conclude that chickpea is a good source of iron and extrusion cooking is a process comparable to home-cooking in terms of iron bioavailability. # 2000 Elsevier Science Ltd. All rights reserved.

Magnesium-deficient high-fat diet: effects on adiposity, lipid profile and insulin sensitivity in growing rats.

BACKGROUND & AIMS To determine if magnesium deficiency aggravates the effects of a high-fat diet in growing rats in terms of obesity, lipid profile and insulin resistance. METHODS The study population comprised 48 newly weaned male Wistar Hannover rats distributed into four groups according to diet, namely, control group (CT; n = 8), control diet provided ad libitum; pair-feeding control group (PF; n = 16), control diet but in the same controlled amount as animals that received high-fat diets; high-fat diet group (HF; n = 12), and magnesium-deficient high-fat diet group (HFMg(-); n = 12). The parameters investigated were adiposity index, lipid profile, magnesium status, insulin sensitivity and the phosphorylation of proteins involved in the insulin-signaling pathway, i.e. insulin receptor β-subunit, insulin receptor substrate 1 and protein kinase B. RESULTS The HF and HFMg(-) groups were similar regarding gain in body mass, adiposity index and lipid profile, but were significantly different from the PF group. The HFMg(-) group exhibited alterations in magnesium homeostasis as revealed by the reduction in urinary and bone concentrations of the mineral. No inter-group differences were observed regarding glucose homeostasis. Protein phosphorylation in the insulin-signaling pathway was significantly reduced in the high-fat groups compared with the control groups, demonstrating that the intake of fat-rich diets increased insulin resistance, a syndrome that was aggravated by magnesium deficiency. CONCLUSIONS Under the experimental conditions tested, the intake of a magnesium-deficient high-fat diet led to alterations in the insulin-signaling pathway and, consequently, increased insulin resistance.

Avaliação por métodos in vitro e in vivo da biodisponibilidade de sulfato ferroso microencapsulado

OBJECTIVE: To evaluate, by in vitro and in vivo methods, the bioavailability of a new microencapsulated ferrous sulfate (Ferlim) developed for food fortification, and compare it with electrolytic iron (Fe0). METHODS: In vitro dialyzability assessment used reconstituted milk powder as matrix. In vivo assessment using the hemoglobin regeneration method in anemic piglets lasted for 13 days and the animals (n=23) were grouped according to the product of weight (kg) x hemoglobin (g/dL). FeSO4.7H2O was used as control. RESULTS: The percentages of dialyzed iron were 2.2 (standard deviation=0.1)%, 3.4 (standard deviation=0.1)% and 3.6 (standard deviation=0.0)% for FeSO4.7H2O, Ferlim and Fe0 respectively (p 0.05). The absorption percentages of the relative biological value of FeSO4.7H2O were 94.2 (standard deviation=23.8)% for the Ferlim group and 79.7 (standard deviation=26.6)% for the Fe0 group; the differences were not significant (p>0.05). In numerical values (p>0.05), the Fe0 group presented the lowest mean relative biological value absorption (%) and concentration of total iron, heme iron and non-heme iron in the liver. CONCLUSION: Microencapsulation of ferrous sulfate with alginate retains its bioavailability therefore it is a good alternative for the fortification of solid mixtures.

Changes in bone mass, biomechanical properties, and microarchitecture of calcium- and iron-deficient rats fed diets supplemented with inulin-type fructans

Feeding mineral-deficient diets enhances absorptive efficiency as an attempt of the body to compensate for the lack of an essential nutrient. Under certain circumstances, it does not succeed; and nutritional deficiency is produced. Our hypothesis was that inulin-type fructans (ITF), which are known to affect mineral absorption, could increase Ca and Fe bioavailability in Ca- and Fe-deficient rats. Male Wistar rats (n = 48, 4 weeks old) were assigned to 1 of 8 groups derived from 2 x 2 x 2 factorial design with 2 levels of added Fe (0 and 35 mg/kg), Ca (0 and 5 g/kg), and ITF (0 and 100 g/kg) for 33 days. The Fe status (hemoglobin, serum Fe, total Fe-binding capacity, transferrin saturation, liver minerals) was evaluated. Tibia minerals (Ca, Mg, and Zn), bone strength, and histomorphometry were determined. In nondeficient rats, ITF supplementation did not affect Fe status or organ minerals, with the exception of tibia Mg. Moreover, ITF improved bone resilience and led to a reduction in eroded surface per body surface and number of osteoclasts per area. In Ca-deficient rats, ITF increased liver (Fe and Zn) and tibia (Zn) mineral levels but impaired tibia Mg, yield load, and resilience. In conclusion, ITF worsened the tibia Mg levels and elastic properties when supplemented in Ca-deficient diets. In contrast, although bone Ca was not affected in nondeficient rats under the present experimental conditions, bone quality improved, as demonstrated by a moderate reduction in femur osteoclast resorption and significant increases in tibia Mg content and elasticity.

Effect of processing on iron bioavailability of extruded bovine lung

Abstract The iron bioavailability of extruded and non-extruded lung products was compared with that of ferrous sulfate by the haemoglobin regeneration method. Extrusion was performed in a laboratory extruder ( L D 20:1) at several processing temperatures and moisture contents of the feed (115–160 °C; 16–30% moisture) with screw (4:1 compression ratio) speed fixed at 200 rpm. These conditions included the optimum observed for lung texturization. Bioavailability of iron was determined as efficiency of haemoglobin regeneration in rats fed bovine extruded lung-based diets, compared with non-extruded lung and casein standard diets. The results showed that iron bioavailability was high and comparable with ferrous sulfate standard, irrespective of the extrusion conditions adopted. These results showed that extruded lung can be used as a good iron source, even if processed in conditions deleterious for other nutrients.

Anemia in Brazilian pregnant women before and after flour fortification with iron

OBJECTIVE To compare prevalence of anemia and hemoglobin (Hb) levels in Brazilian pregnant women before and after flour fortification with iron. METHODS A repeated cross-sectional panel study of public health care centers of municipalities in the five Brazilian regions was conducted. Retrospective data were obtained from 12,119 medical records of pregnant women distributed in two groups: before fortification (delivery prior to June 2004) and after fortification (date of last period after June 2005). Anemia was defined as Hb<11.0 g/dl. Hb levels according to gestational age were assessed using two references from the literature. Statistical analysis was carried out using chi-squared tests, Students t tests, and logistic regression, with a significance level of 5%. RESULTS In the total sample, prevalence of anemia fell from 25% to 20% after fortification (p<0.001). However, important regional differences were evident: while significant reductions were seen in the Northeast (37% to 29%) and North (32% to 25%) regions, where pre-fortification prevalence was high, smaller reductions were seen in the Southeast (18% to 15%) and South (7% to 6%) regions, where prevalence was low. Hb levels according to gestational age were slightly higher in the first months of pregnancy and lower after the third or fourth months, depending on the reference used. Logistic regression analysis showed that group, geographic region, marital status, trimester of pregnancy, initial nutritional status, and prior pregnancy were associated with anemia (p<0.05). CONCLUSIONS Prevalence of anemia decreased after fortification, but remains high in the North and Northeast regions. Although fortification may have played a role in this favorable outcome, the contribution of other public policies implemented during the studied period should also be considered.

Controle da anemia ferropriva em pré-escolares por meio da fortificação de alimento com concentrado de Hemoglobina Bovina (estudo preliminar)

O efeito da introducao de biscoitos fortificados com ferro heminico no estado de nutricao de ferro de pre-escolares foi avaliado em um estudo piloto que inclui 16 criancas, com idade entre 2 e 4 anos, de uma creche publica do estado do Piaui. A fonte de ferro utilizada foi o sangue bovino seco pelo processo de leito de jorro, uma alternativa para a secagem em spray, adaptada para a secagem de sangue. A primeira tomada de amostra, detectou-se anemia (Hb < 11 g/dL) em 12 criancas (75%). O valor medio de Hb foi de 9,4 2,6 g/dL. Os biscoitos fortificados com 3% de concentrado de hemoglobina bovina foram introduzidos na dieta oferecida (5 biscoitos (4mg Fe)/d) durante 3 meses. Apos esse periodo, houve aumento da concentracao de hemoglobina em todas as criancas e ausencia de anemia (Hb = 13,2 0,2 g/dL). Os resultados obtidos apontam para a utilizacao do sangue total seco como uma fonte de ferro heminico possivel de ser utilizada na fortificacao de alimentos, principalmente dirigidos a grupos de risco de anemia por deficiencia de ferro, como e o caso dos pre-escolares.