Comparación del contenido de sodio de alimentos del mercado argentino con el valor del rotulo / Comparation of sodium of foods from argentine market with the nutritional label value

Introducción: el sodio (Na) es un elemento abundante en la naturaleza y presente en el agua y en los alimentos que consumimos. El consumo excesivo de Na que, mayormente, proviene de alimentos procesados, es un factor de riesgo para el desarrollo de hipertensión arterial y de enfermedad cardiovascular. En Argentina, el consumo de Na duplica el consumo máximo recomendado de 2000 mg/día. Objetivo: evaluar el contenido de Na de alimentos del mercado argentino y comparar dichos valores con los declarados en los rótulos nutricionales. Materiales y métodos: se seleccionaron 97 productos de diversas categorías (fiambres, quesos, bebidas analcohólicas, galletitas). La concentración de Na se midió por espectroscopía de emisión y se expresó en mg Na/100 g/mL. Resultados: el contenido declarado de Na para los alimentos analizados fue de 630 [10-1833] (mediana [rango]), mientras que el Na medido fue de 645 [6.9-3278]; para las bebidas analcohólicas el Na declarado fue 14 [0-46] y el Na medido 3.7 [0.8-36]. Se halló diferencia significativa entre los valores de Na declarados y medidos en fiambres y bebidas analcohólicas (test de Wilcoxon, p<0.05). Un 41% del valor medido de Na en los alimentos analizados está dentro de la tolerancia ± 20% que exige el Código Alimentario Argentino y un 92% de las bebidas analcohólicas tienen un valor medido menor a dicho intervalo. Conclusiones: los valores declarados y medidos son diferentes para las categorías de fiambres y bebidas analcohólicas, lo que impediría una correcta estimación de la ingesta de Na a partir de estos alimentos

Introduction: sodium (Na) is an element abundant in nature and present in the water and food. The excessive consumption of Na, which mainly comes from processed foods, is a risk factor for the development of high blood pressure and cardiovascular disease. In Argentina, Na consumption doubles the maximum recommended consumption of 2000 mg/day. Objective: to evaluate the Na content of foods in the Argentine market and to compare the values of these with those declared in the nutritional labels. Materials and Methods: 97 products were selected from various categories (cold cuts, cheeses, sweetened beverages, cookies). The Na concentration was measured by emission spectroscopy and was expressed in mg Na/100 g/mL. Results: The median and range of the declared Na was for the foods analyzed was 630 [10-1833] (median [range]), while the measured Na was 645 [6.9-3278]; for non-alcoholic beverages, declared Na was 14 [0-46] and measured Na was 3.7 [0.8-36]. A significant difference was found between the Na values declared and measured in cold cuts and sweetened beverages (Wilcoxon test, p<0.05). Forty one percent of the measured value of Na in the foods analyzed are within the tolerance ± 20% required by The Argentine Food Code and 92% of the non-alcoholic beverages have a measured value lower than said interval. Conclusions: the declared and measured values are different for the categories of cold cuts and non-alcoholic beverages, which would prevent a correct estimation of the Na intake from these foods

Estimación de la ingesta de calcio y fosfato a partir de bebidas analcohólicas / Calcium and phosphate intake from analcoholic beverages

El calcio (Ca) es un nutriente crítico para la salud, especialmente en los períodos de crecimiento. Sin embargo, la mayoría de los individuos argentinos no alcanzan la ingesta diaria recomendada. Por su parte, el fósforo (P) es un nutriente cuya ingesta suele estar por encima de la recomendada. Este tipo de desequilibrio en la ingesta de ambos nutrientes conlleva a una pérdida de masa ósea. El consumo de bebidas analcohólicas (BA) se ha incrementado en los últimos años, sobre todo en la población infantil, desplazando el consumo de agua y lácteos. El objetivo de este trabajo fue estimar el aporte de Ca y P a partir de BA diferentes de agua. Se evaluaron 59 muestras, cuya mediana y rango de Ca fue de 7,74 [0,00 a 111,29] mg/l y de P 55,17 [0,16 a 957,00] mg/l. Los jugos en polvo son los que mayor contenido de Ca presentaron y las bebidas deportivas aquellas donde se halló el mayor contenido de P. Considerando un consumo de 500 ml/día de BA se estarían incorporando 3,87 mg Ca y 27,59 mg P. El creciente consumo de BA, su bajo contenido de Ca y la concomitante reducción del consumo de lácteos contribuyen a una inadecuada ingesta de Ca. (AU)

Calcium (Ca) is a critical nutrient, especially during periods of growth. However, the majority of Argentine individuals do not reach the recommended daily intake. On the other hand, phosphorus (P) is a nutrient with an intake usually above the recommended values. This type of imbalance between the intake of the nutrients leads to loss of bone mass. Soft drinks consumption (BA) has increased in recent years, especially in children, displacing the consumption of water and dairy products. The aim of this work was to estimate the Ca and P content in BA other than water. 59 samples were evaluated, with a median and range of Ca of 7.74 [0.00 to 111.29] mg/l and of P of 55.17 [0.16 to 957.00] mg/l. Powdered juices are the ones with the highest Ca content, and sports drinks are the beverages in which the highest P content was found. Based on a BA consumption of 500 ml/day, 3.87 mg Ca and 27.59 mg P would be incorporated. Therefore, the increased consumption of BA, their low Ca content, and the concomitant reduction in dairy consumption contribute to an inadequate intake of Ca. (AU)

Contribution of calcium in drinking water from a South American country to dietary calcium intake.

OBJECTIVE: To describe the calcium concentration of tap and bottled waters from Argentina and to estimate the contribution of drinking water to calcium recommendations. RESULTS: Calcium concentrations provided by water authorities ranged from 6 to 105 mg/L. The mean calcium level of samples analysed at the Laboratorio de Ingeniería Sanitaria, National University of La Plata was 15.8 (SD ± 13.2) mg/L and at the Bone Biology Laboratory of the National University of Rosario was 13.1 (± 10.0) mg/L. Calcium values of samples from supply systems and private wells was similar. Most bottled waters had calcium levels well below 50 mg/L. The intake of one litre of drinking water from Argentina could represent in average between 1.2 and 8.0% of the calcium daily values for an adult.

Bone Strength in Growing Rats Treated with Fluoride: a Multi-dose Histomorphometric, Biomechanical and Densitometric Study.

Bone deformation and fragility are common signs of skeletal fluorosis. Disorganisation of bone tissue and presence of inflammatory foci were observed after fluoride (F-) administration. Most information about F- effects on bone has been obtained in adult individuals. However, in fluorosis areas, children are a population very exposed to F- and prone to develop not only dental but also skeletal fluoroses. The aim of this work was to evaluate the bone parameters responsible for the effect of different doses of F- on fracture load of the trabecular and cortical bones using multivariate analysis in growing rats. Twenty-four 21-day-old Sprague-Dawley rats were divided into four groups: F0, F20, F40 and F80, which received orally 0, 20, 40 or 80 µmol F-/100 g bw/day, respectively, for 30 days. After treatment, tibiae were used for measuring bone histomorphometric and connectivity parameters, bone mineral density (BMD) and bone cortical parameters. The femurs were used for biomechanical tests and bone F- content. Trabecular bone volume was significantly decreased by F-. Consistently, we observed a significant decrease in fracture load and Young's modulus (YM) of the trabecular bone in F--treated groups. However, cortical bone parameters were not significantly affected by F-. Moreover, there were no significant differences in cortical nor trabecular BMD. Multivariate analysis revealed a significant correlation between the trabecular fracture load and YM but not with bone volume or BMD. It is concluded that when F- is administered as a single daily dose, it produces significant decrease in trabecular bone strength by changing the elasticity of the trabecular bone.

In vivo measurement of the rate constant of liver handling of glucose and glucose uptake by insulin-dependent tissues, using a mathematical model for glucose homeostasis in diabetic rats.

Diabetes mellitus is a disease that affects glucose homeostasis. The World Health Organization informs that there are over 347 million people in the world with diabetes. The diagnosis and characterization of glucose homeostasis in different metabolic conditions are subjects of great importance with high clinical impact. There are many mathematical models that describe the glucoregulatory system in detail. However, the use of these models is limited because they have a large number of mathematical equations and parameters and they require complex methodologies to estimate of them. This forced to work with average values that decrease the validity of results and the applicability of the models. In this study two mathematical models for rats with diabetes mellitus were developed. The difference between these models and others lies in the possibility of obtaining all parameters for each animal from simple measurements (glucose and insulin plasma levels). Moreover, the models allow to measure in vivo the different physiological processes involved in glucose homeostasis in animals: insulin secretion and its plasma clearance, absorption of insulin from a subcutaneous injection, the liver handling of glucose, intestine absorption of glucose, glucose uptake rate of insulin-independent tissues, glucose uptake rate of insulin-dependent tissues, and renal glucose excretion.

Comparison of fluoride effects on germination and growth of Zea mays, Glycine max and Sorghum vulgare.

BACKGROUND: Fluorosis is a disease caused by over-exposure to fluoride (F). Argentina's rural lands have higher fluorine content than urban lands. Evidence confirms that plants grown in fluoridated areas could have higher F content. We compared F uptake and growth of crops grown in different F concentrations. The effect of 0-8 ppm F concentrations on maize, soybeans and sorghum germination and growth was compared. After 6 days seeding, the germination was determined, the roots and aerial parts lengths were measured, and vigor index was calculated. F content was measured in each part of the plants. Controls with equal concentrations of NaCl were carried out. RESULTS: Significant decrease in roots and aerial parts lengths, and in vigor index of maize and soybeans plants was observed with F concentrations greater than 2 ppm. This was not observed in sorghum seedlings. Also, the amount of F in all crops augmented as F increases, being higher in roots and ungerminated seeds. Sorghum was the crop with the highest F content. CONCLUSION: Fluoride decreased the germination and growth of maize and soybeans and therefore could influence on their production. Conversely, sorghum seems to be resistant to the action of F. © 2015 Society of Chemical Industry.

Methodology developed for the simultaneous measurement of bone formation and bone resorption in rats based on the pharmacokinetics of fluoride.

This paper describes a novel methodology for the simultaneous estimation of bone formation (BF) and resorption (BR) in rats using fluoride as a nonradioactive bone-seeker ion. The pharmacokinetics of flouride have been extensively studied in rats; its constants have all been characterized. This knowledge was the cornerstone for the underlying mathematical model that we used to measure bone fluoride uptake and elimination rate after a dose of fluoride. Bone resorption and formation were estimated by bone fluoride uptake and elimination rate, respectively. ROC analysis showed that sensitivity, specificity and area under the ROC curve were not different from deoxypiridinoline and bone alkaline phosphatase, well-known bone markers. Sprague-Dawley rats with modified bone remodelling (ovariectomy, hyper, and hypocalcic diet, antiresorptive treatment) were used to validate the values obtained with this methodology. The results of BF and BR obtained with this technique were as expected for each biological model. Although the method should be performed under general anesthesia, it has several advantages: simultaneous measurement of BR and BF, low cost, and the use of compounds with no expiration date.

Regulation of intestinal calcium absorption by luminal calcium content: role of intestinal alkaline phosphatase.

SCOPE: Intestinal alkaline phosphatase is a brush border enzyme that is stimulated by calcium. Inhibition of intestinal alkaline phosphatase increases intestinal calcium absorption. We hypothesized that intestinal alkaline phosphatase acts as a minute-to-minute regulatory mechanism of calcium entry. The aim of this study was to evaluate the mechanism by which intestinal luminal calcium controls intestinal calcium absorption. METHODS AND RESULTS: We performed kinetic studies with purified intestinal alkaline phosphatase and everted duodenal sacs and showed that intestinal alkaline phosphatase modifies the luminal pH as a function of enzyme concentration and calcium luminal content. A decrease in pH occurred simultaneously with a decrease in calcium absorption. The inhibition of intestinal alkaline phosphatase by l-phenylalanine caused an increase in calcium absorption. This effect was also confirmed in calcium uptake experiments with isolated duodenal cells. CONCLUSION: Changes in luminal pH arising from intestinal alkaline phosphatase activity induced by luminal calcium concentration modulate intestinal calcium absorption.

Mathematical model of glucose-insulin homeostasis in healthy rats.

According to the World Health Organization there are over 220 million people in the world with diabetes and 3.4 million people died in 2004 as a consequence of this pathology. Development of an artificial pancreas would allow to restore control of blood glucose by coupling an infusion pump to a continuous glucose sensor in the blood. The design of such a device requires the development and application of mathematical models which represent the gluco-regulatory system. Models developed by other research groups describe very well the gluco-regulatory system but have a large number of mathematical equations and require complex methodologies for the estimation of its parameters. In this work we propose a mathematical model to study the homeostasis of glucose and insulin in healthy rats. The proposed model consists of three differential equations and 8 parameters that describe the variation of: blood glucose concentration, blood insulin concentration and amount of glucose in the intestine. All parameters were obtained by setting functions to the values of glucose and insulin in blood obtained after oral glucose administration. In vivo and in silico validations were performed. Additionally, a qualitative analysis has been done to verify the aforementioned model. We have shown that this model has a single, biologically consistent equilibrium point. This model is a first step in the development of a mathematical model for the type I diabetic rat.

Physical exercise ameliorates the toxic effect of fluoride on the insulin-glucose system.

Daily intake of water with fluoride concentrations >1.5 mg/l produces insulin resistance (IR). On the other hand, physical activity increases insulin sensitivity in the muscle. Therefore, the aim of this study was to evaluate the effect of physical activity on IR in rats treated with sodium fluoride (NaF) in drinking water. Sprague-Dawley rats were divided into three groups (n=10/group): Control (drinking water without NaF), NaF (drinking water with NaF 15 mg/l for 30 days), and Exercise (daily running on a treadmill for 60 min at 2.25 m/min and drinking water with NaF 15 mg/l for 30 days). IR was evaluated with the homeostasis model assessment-IR (HOMA-IR) index using fasting plasma levels of glucose and insulin. IR increased in rats treated with 15 mg/l NaF in drinking water. A decrease in IR was observed in rats that performed physical activity and drank water with 15 mg/l NaF; the Exercise group also showed an increase in the amounts of bone fluoride. The variation in the HOMA-IR values could be the consequence of variation in the sensitivity of tissues to insulin or decrease in plasma fluoride levels due to bone fluoride intake. These findings indicate that the performance of daily physical activity could reduce the negative effects of the chronic ingestion of NaF on glucose homeostasis.

Chicken eggshell as suitable calcium source at home.

AIM: Taken into consideration that the deficiency of calcium (Ca) in the diet is a common problem, the aim of this work was to study the chicken eggshell as Ca source at home. It was evaluated: (1) different mechanisms to process eggshells and find an easy way to determine the required amount of Ca at home and; (2) the flavor and the texture for eggshell fortified food. METHODS: Chemical and mechanical methods of eggshell processing were evaluated. Changes in flavor and texture were evaluated in volunteers coordinated by a professional chef. RESULTS: A single eggshell contains 2.07 ± 0.18 g of Ca; therefore half an eggshell could provide the amount of Ca needed by adult human beings per day. The best way to use chicken eggshell as Ca dietary supplement is powdered to add to bread, pizza or spaghetti as there were small changes in texture and no changes in flavor.

Effect of fluoridated water on plasma insulin levels and glucose homeostasis in rats with renal deficiency.

Glucose intolerance in fluorosis areas and when fluoride is administered for the treatment of osteoporosis has been reported. Controlled fluoridation of drinking water is regarded as a safe and effective measure to control dental caries. However, the effect on glucose homeostasis was not studied so far. The aim of this study was to evaluate the effect of the intake of fluoridated water supply on glucose metabolism in rats with normal and deficient renal function. Male Sprague-Dawley rats were divided into eight groups of four rats. Renal insufficiency was induced in four groups (NX) which received drinking water containing 0, 1, 5, and 15 ppm F (NaF) for 60 days. Four groups with simulated surgery acted as controls. There were no differences in plasma glucose concentration after a glucose tolerance test between controls and NX rats and among rats with different intakes of fluoride. However, plasma insulin level increased as a function of fluoride concentration in drinking water, both in controls and in NX rats. It is concluded that the consumption of fluoridated water from water supply did not affect plasma glucose levels even in cases of animals with renal disease. However, a resistance to insulin action was demonstrated.

Control de la tetania en modelos quirúrgicos de hipocalcemia en ratas / Management of tetany in hypocalcemic models in the rat

La remodelación ósea es un proceso bajo el control de un complejo mecanismo que involucra factores endócrinos, autócrinos y parácrinos. La hipocalcemia tiene en parte el control de la remodelación ósea por modificación de los niveles de parathormona (PTH). La disminución de la acción de PTH produce un estado de baja remodelación ósea. La disminución de la función paratiroidea se puede lograr en la rata por ablación simultánea de tiroides y paratiroides (tiroparatiroidectomía: TPTX) o por ablación de las glándulas paratiroideas (paratiroidectomía: PX). TPTX es una cirugía de baja complejidad y requiere administración posterior de hormonas tiroideas en agua de bebida. PX requiere más entrenamiento pero no la administración de tiroxina. En ambos casos la hipocalcemia es el signo indicador del éxito de la ablación, cuyo valor es cercano o inferior a 7.5 mg/dl. La búsqueda de modelos de hipocalcemia para obtener estados de baja remodelación ósea ha demostrado que la tetania asociada a la hipocalcemia es la complicación más importante en el mantenimiento de los animales y la realización de cirugías posteriores. Se realizaron cirugías de PX, TPTX y ablación de una de las dos glándulas paratiroideas (1/2PX). Los resultados hallados indican que la PX y 1/2PX producen hipocalcemia más severa que TPTX y la 1/2PX produce un modelo de hipocalcemia muy severa pero transitoria. La administración de gluconato de calcio en agua de bebida evita la presencia de tetania durante el mantenimiento de los animales, pero no durante cirugías con anestesia general. La administración de gluconato de calcio intramuscular evita la tetania que se produce como consecuencia de la anestesia general.

Método mininvasivo de medición de la remodelación ósea en ratas: validación en distintos modelos biológicos / Non-invasive technique for the measurement of bone remodeling in rats: validation in different biological models

La remodelación ósea puede medirse con marcadores bioquímicos óseos, isótopos radioactivos e histomorfometría. En este trabajo se propone un método basado en la farmacocinética del fluoruro. El método consiste en la medición de la fluoremia y la excreción urinaria de fluoruro antes y después de una dosis endovenosa de fluoruro. Con los datos obtenidos se aplica un modelo matemático y se calcula la resorción (Ro) y formación ósea (Fo), medidos en mol/l.min. El método fue validado en ratas Sprague-Dawley con osteoporosis inducida por ovariectomía (OVX), con tratamiento con zoledronato (OVX+Z), con insuficiencia renal por nefrectomía parcial (NFX) y con paratiroidectomía (PX). En todos los casos se utilizó un grupo control (C) y cada grupo experimental contuvo 5 ratas; se utilizaron los test de Kruskal Wallis y Mann Whitney, considerando diferencias significativas si p <0,05. Fo y Ro fueron mayores en OVX (Fo=1,36±0,56 [X±EE]; Ro=1,84 ±0,47) con respecto a C (Fo=0,50±0,07; Ro=0,56±0,38) y a OVX+Z (Fo=0,34±0,17; Ro=0,45±0,18). Fo y Ro fueron mayores en ratas NFX (Fo=5,00±0,40; Ro=5,08±0,45) con respecto a C (Fo=0,55±0,14; Ro=0,56±0,14). Fo y Ro fueron menores en PX (Fo=0,75±0,08; Ro=0,96±0,06) respecto de C (Fo=1,20±0,32; Ro=1,44±0,27). Conclusiones: el método es de bajo costo, mini-invasivo, requiere reducido volumen de sangre, permite el seguimiento de tratamientos con otras drogas y el mismo marcador es utilizado para medir ambos procesos. Los valores de resorción y formación ósea obtenidos coincidieron con los valores que se esperaban en los modelos biológicos estudiados.