RESUMEN

BACKGROUND: There are few effectiveness evaluations of food fortification programs, and little is known about what makes programs successful. OBJECTIVE: We examined 3 food fortification programs in Latin America to identify common features that might explain their success and to draw lessons for program design and implementation everywhere: The vitamin A fortification of sugar in Guatemala with impact on vitamin A status of the population, the fortification of a basket of foods with iron and other micronutrients in Costa Rica with impact on iron status and anemia in women and children, and the fortification of wheat flour with folic acid in Chile, which reduced the incidence of neural tube defects. METHODS: We identified pertinent literature about these preselected programs and asked regional experts for any additional information. We also conducted structured interviews of key informants to provide historical and contextual information. RESULTS: Institutional research capacity and champions of fortification are features of successful programs in Latin America. We also found that private/public partnerships (industry, government, academia, and civil society) might be key for sustainability. To achieve impact, program managers need to use fortification vehicles that are consumed by the nutritionally vulnerable and to add bioavailable fortificants at adequate content levels in order to fill dietary gaps and reduce micronutrient deficiencies. Adequate monitoring and quality control are essential. CONCLUSIONS: For future programs, we recommend that the evaluation be specified up-front, including a baseline/end line and data collection along the program impact pathway to inform needed improvements and to strengthen causal inferences.

Asunto(s)

RESUMEN

Undernutrition and micronutrient deficiencies are still a public health problem in Latin America and the Caribbean (LAC), and overweight and obesity have reached epidemic proportions. To assess the nutrition landscape in LAC countries and guide future nutrition efforts and investments, the Pan American Health Organization and the Micronutrient Initiative joined efforts to 1) identify information gaps and describe the current nutritional situation in the region; 2) map existing policies to address malnutrition in Latin America; 3) describe the impact of conditional cash transfer programs (CCTs) on nutrition and health outcomes; and 4) identify the challenges and opportunities to address malnutrition in the region. This article summarizes the methods and key findings from that research and describes the current challenges and opportunities in addressing malnutrition in the LAC region. LAC countries have advanced in reducing undernutrition and micronutrient deficiencies, but important gaps in information are a major concern. These countries have policies to address undernutrition and micronutrient deficiencies, but comprehensive and intersectoral policies to tackle obesity are lacking. CCTs in Brazil, Colombia, and Mexico have been reported to have a positive impact on child nutrition and health outcomes, providing an opportunity to integrate nutrition actions in intersectoral platforms. The current epidemiological situation and policy options offer an opportunity for countries, technical agencies, donors, and other stakeholders to jointly scale up nutrition actions. This can support the development of comprehensive and intersectoral policies to tackle the double burden of malnutrition, strengthen national nutrition surveillance systems, incorporate monitoring and evaluation as systematic components of policies and programs, document and increase investments in nutrition, and assess the effectiveness of such policies to support political commitment and guarantee sustainability.

Asunto(s)

RESUMEN

ABSTRACT Objective To determine the current nutritional status in Latin America and the Caribbean (LAC) and identify data gaps and trends in nutrition surveillance. Methods A systematic Internet search was conducted to identify official sources that allowed for monitoring of LAC countries’ nutritional status, including progress toward World Health Organization Global Nutrition Targets 2025. Reports from national nutrition surveillance systems and reports on nationally representative surveys were collected and collated to 1) analyze nutritional status, based on life-course anthropometric indicators and biomarkers, and 2) identify gaps in data availability and trends in nutritional deficiencies. Information on iron, vitamin A, iodine, folate, and vitamin B12 deficiency was also collected and collated. Results Twenty-two of the 46 LAC countries/territories (48%) had information on undernutrition (stunting, underweight, and wasting) in children under 5 years old and women of reproductive age (WRA). Seventeen countries (38%) had information on anemia in children under 5 years old and WRA, and 12 (27%) had information on anemia in pregnant women. Although overall nutritional status has improved in the past few decades in all countries in the region, some LAC countries still had a high prevalence of stunting and anemia in children and WRA. Overweight affected at least 50% of WRA in nine countries with available data, and was increasing in children. Data for school-age children, adolescents, adult males, and older adults were scarce in the region. Conclusions Overall nutritional status has improved in the LAC countries with available information, but more efforts are needed to scale up nutrition-sensitive and nutrition-specific interventions to tackle malnutrition in all its forms, as stunting, anemia, and vitamin A deficiency are still a public health problem in many countries, and overweight is an epidemic. Nutrition information systems are weak in the region, and countries need to strengthen their capacity to monitor nutritional status indicators.

RESUMEN Objetivo Determinar la situación actual de las carencias nutricionales en América Latina y el Caribe (ALC) e identificar las deficiencias en los datos y el curso actual de la vigilancia en materia de nutrición. Métodos Se realizó una búsqueda sistemática de la internet para encontrar fuentes oficiales dedicadas a observar la evolución de la situación nutricional de los países de América Latina y el Caribe, incluidos los avances en relación con las metas mundiales de nutrición fijadas por la Asamblea Mundial de la Salud para el 2025. Se recopilaron y compaginaron los informes de diferentes sistemas de vigilancia nutricional nacionales y de encuestas representativas de alcance nacional con el fin de: (1) analizar la situación nutricional con respecto a indicadores antropométricos y marcadores biológicos para todas las etapas de la vida y (2) detectar brechas en la disponibilidad de datos y observar la evolución de las carencias nutricionales. También se recopiló y compaginó información relativa a la carencia de hierro, vitamina A, yodo, folato y vitamina B12. Resultados Veintidós países de América Latina y el Caribe (48%) contaban con información acerca de la desnutrición (retraso del crecimiento, peso inferior al normal y emaciación) en niños menores de 5 años de edad, niños en edad escolar, adolescentes y mujeres en edad fecunda (MEF). Diecisiete países (38%) tenían información sobre la anemia en niños menores de 5 años; 12 (27%) la tenían sobre la anemia en MEF. Aunque la situación nutricional en general ha mejorado en los últimos decenios en todos los países de la Región, algunos países de América Latina y el Caribe siguen teniendo una alta prevalencia de retraso del crecimiento y anemia en niños y MEF. El sobrepeso afectaba a por lo menos 50% de las MEF en nueve de los países que poseían datos y estaba aumentando en los niños. En la Región hay pocos datos relativos a los niños en edad escolar, los adolescentes, los hombres adultos y las personas de edad. Conclusiones La situación nutricional en general ha mejorado en los países de América Latina y el Caribe para los cuales se cuenta con información, pero hay que tomar más medidas para incrementar las intervenciones relacionadas de manera tangencial o directa con la nutrición a fin de combatir la desnutrición en todas sus manifestaciones, habida cuenta de que el retraso del crecimiento, la anemia y la carencia de vitamina A siguen siendo problemas de salud pública en muchos países y que el sobrepeso constituye una epidemia. Los sistemas de información nutricional de la Región son pobres y los países tienen que fortalecer su capacidad para vigilar los indicadores de la situación nutricional.

Asunto(s)

RESUMEN

OBJECTIVES: Calcium (Ca) and iron (Fe) are essential minerals for normal growth and development. Although previous studies have shown that Ca inhibits acute Fe absorption, there is no evidence of the possible long- or medium-term effects of Ca supplementation on Fe bioavailability. The aim of this study was to determine the effect of 34 d of Ca supplementation on heme Fe and non-heme Fe bioavailability in non-pregnant women of ages 33 to 47 y. METHODS: This was a prospective, randomized, double-blind, placebo-controlled trial. Twenty-six healthy women (40 ± 5 y) were randomly assigned to receive either 600 mg of elemental Ca/d as CaCO3 (Ca group, n = 13) or a placebo (P group, n = 13) for 34 d. Heme Fe and non-heme Fe bioavailability were determined before and after treatment using (55)Fe and (59)Fe radioisotopes. A two-factor, repeated-measures analysis of variance was used to assess differences by treatment and timing. RESULTS: The geometric mean (range ± 1 SD) of heme Fe bioavailability before and after treatment was 16.5% (8.3-32.8) and 26% (15.5-43.6) for the Ca group and 21.8% (13.0-36.6) and 25.1% (16.5-38.3) for the P group. Non-heme Fe bioavailability before and after treatment was 39.5% (19.9-78.7) and 34.1% (19.1-60.6) for the Ca group, and 44.6% (24.9-79.7) and 39.3% (24.3-63.4) for the P group. There were no differences in either heme Fe or non-heme Fe bioavailability either at baseline or after treatment. CONCLUSION: The administration of calcium supplements for 34 d does not affect iron bioavailability. This trial is registered with Controlled-trials.gov, number ISRCTN 89888123.

Asunto(s)

RESUMEN

Iron (Fe) and zinc's (Zn) interaction at the absorptive level can have an effect on the success of co-fortification of wheat flour with both minerals on iron deficiency prevention. The aim of the study was to determine the effect of increasing levels of zinc fortificant on the iron absorption of bread co-fortified with iron and zinc consumed with a black tea. Twelve women aged 33-42 years participated in the study. They received on four different days 200 mL of black tea and 100 g of bread made with wheat flour (70% extraction) fortified with either 30 mg Fe/kg alone, as ferrous sulfate (A), or with the same Fe-fortified flour, but with graded levels of Zn, as zinc sulfate: 30 mg/kg (B), 60 mg/kg (C), or 90 mg/kg (D). Fe radioisotopes ((59)Fe and (55)Fe) of high specific activity were used as tracers, and Fe absorption iron was measured by the incorporation of radioactive Fe into erythrocytes. The geometric mean and range of ±1 SD of Fe absorption were as follows: A = 6.5% (2.2-19.3%), B = 4.6% (1.0-21.0%), C = 2.1% (0.9-4.9%), and D = 2.2% (0.7-6.6%), respectively; ANOVA for repeated measures F = 10.9, p < 0.001 (Scheffè's post hoc test: A vs. C, A vs. D, B vs. C, and B vs. D; p < 0.05). We can conclude that Fe absorption of bread made from low-extraction flour fortified with 30 mg/kg of Fe, as ferrous sulfate, and co-fortified with zinc, as zinc sulfate consumed with black tea is significantly decreased at a zinc fortification level of ≥60 mg/kg flour.

Asunto(s)

RESUMEN

Iron (Fe) and zinc (Zn) deficiencies constitute two of the most important nutritional and public health problems affecting developing countries. Combined supplementation or fortification with Zn and Fe are strategies that can be used to improve the Zn and Fe status of a population. However, there is concern about potential negative interactions between these two micronutrients due to a competitive binding to DMT1 and Zip14 transporter. Studies performed in humans have shown an inhibitory effect of Zn on Fe absorption when both minerals are given together as a solution in fasting conditions. We found that at low doses of iron (0.5 mg) the threshold for the inhibition of iron bioavailability was at a Zn:Fe wt/wt ratio ≥5.9:1, whereas at higher doses of Fe (10 mg) this inhibition occurred at 1:1 Zn:Fe wt/wt ratio. This differential response could be explained by the variation in the abundance of both cations as they compete for a limited number of shared transporters at the enterocyte. Conflicting results have been obtained when this interaction was studied in different food matrices. A negative interaction was not observed when Fe and Zn were provided in a composite hamburger meal, premature formula, human milk, or cow milk. A decrease on Fe absorption was observed in only 1 of 3 studies when Fe and Zn were supplied in wheat flour. The possibility of a negative interaction should be considered for supplementation or fortification programs with both microminerals.

Asunto(s)

RESUMEN

OBJECTIVE: To study heme iron bioavailability and the role of dietary protein (animal and vegetable) on iron uptake using an in vitro model (Caco-2 cell line). METHODS: Caco-2 cells were seeded in bicameral chambers with different animal (beef, chicken or fish) or vegetable (peas, lentils, and soybeans) proteins or with pure animal (collagen and casein) or vegetable (gliadin, zein, and glutein) protein extracts. The effect of each protein over heme iron absorption was assessed. RESULTS: Intact heme uptake was higher than either heme plus albumin or digested heme plus albumin, but lower than digested heme. White meal exerted the highest inhibitory effect on hemin uptake. Heme iron uptake decreased in the presence of all legume extracts, but was not significantly different among them (one-way ANOVA, NS). Pure animal (collagen and casein) and vegetable (zein and glutelin) proteins increased heme iron uptake, except for gliadin. CONCLUSION: Animal and vegetable protein in general decreased heme iron uptake. However, purified animal and vegetable protein induce an increase in heme iron uptake.

Asunto(s)

RESUMEN

The aim of this study is to determine the content of total iron (TFe), heme iron (HeFe), zinc (Zn), and copper (Cu) in different cuts of meat and viscera from rabbit. Five young New Zealand rabbits were used in the study. Samples in triplicate were obtained from three meat cuts (foreleg, hind leg, and loin) and from main viscera. TFe, Zn, and Cu concentrations from samples were determined by wet acid digestion followed by atomic absorption spectrophotometry (AAS), while HeFe was determined by acid extraction followed by AAS. Mean TFe, HeFe, Zn, and Cu in meat was 0.83 ± 0.09, 0.56 ± 0.11, 0.95 ± 0.35, and 0.08 ± 0.01 mg/100 g, respectively. TFe content was less than 1 mg/100 g in all meat cuts. Sixty-seven percent of iron content was HeFe. The cut of meat with highest Zn concentrations was the foreleg with 1.33 ± 0.12 mg/100 g. Cu content was low for all meat cuts. TFe, HeFe, Zn, and Cu content in viscera varied greatly. The spleen was the organ with the highest TFe and Zn concentrations (82.79 ± 9.22 mg/100 g and 3.49 ± 0.63 mg/100 g, respectively). Nevertheless, the lungs had the highest concentration of HeFe (5.79 ± 0.90 mg/100 g), accounting for 91% of the total iron. The liver had the highest Cu content (3.89 ± 0.89 mg/100 g). Rabbit meat has low TFe concentration, similar to that of poultry, and most of the iron is HeFe. The amount of minerals in viscera closely depends on their function.

Asunto(s)

RESUMEN

Copper is an essential micronutrient involved in a variety of biological processes indispensable to sustain life. At the same time, it can be toxic when present in excess, the most noticeable chronic effect being liver damage. Potent, efficient regulatory mechanisms control copper absorption in the digestive tract and copper biliary excretion; absorption ranges between 12 and 60% in humans, depending on Cu intake, presence of other factors in the diet that may promote or inhibit its absorption and on the copper status of the individual. Current evidence suggests that copper deficiency may be more prevalent than previously thought, while copper toxicity is uncommon under customary daily life conditions. Menkes syndrome and Wilson disease are genetic conditions associated with severe copper deficiency and severe copper toxicity, respectively. Effects of milder degrees of copper deficiency and excess copper exposure are not well described, mainly due to lack of sensitive and specific indicators; serum copper concentration and ceruloplasmin are the most frequently used indicators, but they only detect rather intense changes of copper status. Of the many proteins assessed as potential markers of copper status the chaperone of Zn-Cu superoxide dismutase (CCS1) has yielded promising results; data on its performance under different conditions are needed to confirm its use as an indicator of early copper deficiency. Defining copper requirements and upper safe limits of consumption (UL) is a complex process since there are adverse health consequences from both copper deficiency and copper excess (U shape curve). The regulatory framework for risk assessment of essential trace elements introduced by the International Programme on Chemical Safety (IPCS) has proposed a homeostatic model to determine the Adequate Range of Oral Intake (AROI) of essential trace elements; the nadir of the resulting U shape curve serves to define the AROI. At this range of intake physiological mechanisms allow for normal homeostasis and basically, there are no detectable adverse effects. At present, Recommended Dietary Intakes (DRIs) and Adequate Intakes (AIs) are used to recommend copper intakes at different ages and life situations. Evidence obtained in humans and non-human primates presented here suggest that current copper UL should be re evaluated. Developing the scientific basis for a copper UL and evaluating the relevance of copper deficiency globally are future key challenges for copper researchers.

Asunto(s)

RESUMEN

To determine the content of total iron (TFe) and heme iron (HeFe) in major cuts of meat and principal viscera of bovine origin. 55Fe (30 mCi) was injected into two 4-month-old calves. Triplicate samples of the 12 basic American cuts of meat and major viscera were obtained from each specimen. Samples were acid digested and their iron content was read by atomic absorption spectrophotometry. Duplicate samples of the basic cuts of meat and major viscera were analyzed to determine the concentration of 55Fe using a double isotopic technique. The mean and standard deviation of TFe for all cuts was 1.4 ± 0.3 mg/100 g of meat. The mean TFe for organs was (per mg/100 g): 0.9 ± 0.1 brain, 3.0 ± 0.05 kidney, 3.2 ± 0.04 heart, 5.7 ± 0.2 lung, 6.0 ± 0.1 liver, and 31.2 ± 0.4 spleen. HeFe was 64% of TFe in meat and 72.8% in spleen, 53.8% in lung, 35.7% in brain, 35.0% in kidney, 27.3% in heart, and only 13.6% in liver. Blood contained 85.5% of the radioisotope and only 1.4% was found in muscle and 1.6% was found in viscera. Results suggest that bovine cuts of meat have a low variation in TFe and that HeFe comprises more than 60% of TFe.

Asunto(s)