Processed complementary food does not improve growth or hemoglobin status of rural tanzanian infants from 6-12 months of age in Kilosa district, Tanzania

Nutrition Education Package Focusing on Infant and Young Child Feeding in Tanzania

OBJECTIVE

To evaluate the effectiveness of a nutrition education package on feeding practices, nutrient intakes and growth of infants in rural Tanzania.

DESIGN

Cluster-randomized controlled trial in 18 villages allocated to nutrition education package (n = 9) or routine health education (n = 9 villages), measured at baseline (6 months) and end of the trial (12 months).

SETTING

Mpwapwa district.

PARTICIPANTS

Infants aged 6-12 months and their mothers.

INTERVENTION(S)

Six months of nutrition education package (group education, counseling, cooking demonstrations) and regular home visits by village health workers.

MAIN OUTCOME MEASURE(S)

Primary outcome measure was the mean change in length-for-age z-scores. Secondary outcomes included mean changes in weight-for-length z-scores (WLZ), intakes of energy, fat, iron and zinc, the proportion of children consuming foods from ≥ 4 food groups (ie, dietary diversity) and consuming the recommended number of semisolid/soft meals and snacks per day (ie, meal frequency).

ANALYSIS

Multilevel mixed-effects regression models.

RESULTS

Mean change in length-for-age z-scores (β = 0.20, P = 0.02), energy (in kcal) (β = 43.8, P = 0.02), and fat (in grams) (β =2.7, P = 0.03) intakes were significant in the intervention but not in the control group. There was no effect on iron and zinc intakes. More infants in the intervention than the control group consumed meals from ≥ 4 food groups (71.8% vs 45.3%, P = 0.002). The mean increase in meal frequency (β = 0.29, P = 0.02) and dietary diversity (β = 0.40, P = 0.01) were more significant in the intervention than control.

CONCLUSIONS AND IMPLICATIONS

The nutrition education package is feasible and can be implemented with high coverage, demonstrating the potential to improve feeding practices, nutrient intake and growth in rural Tanzania.

Aflatoxin Contamination, Exposure among Rural Smallholder Farming Tanzanian Mothers and Associations with Growth among Their Children

Recently, aflatoxin exposure especially through maize and groundnuts has been associated with growth impairment in children. Infants and children are considered to be more susceptible to toxins because of their lower body weight, higher metabolic rate, and lower ability to detoxify. On the other hand, for women of reproductive age, aflatoxin exposure may not only affect their health but also that of their foetus in the case of pregnancy. This study focused on investigating AFB1 contamination in maize and groundnut from respondent households, exposure among women of reproductive age and associations of aflatoxin contamination with growth retardation among children in Mtwara region, Tanzania. The highest maximum AFB1 contamination levels from all samples obtained were in maize grain (2351.5 μg/kg). From a total of 217 maize samples collected, aflatoxins were above European Union (EU) and East African Community (EAC) tolerable limits in 76.0% and 64.5% of all samples. Specifically, maize grain had the highest proportion of samples contaminated above tolerable limits (80.3% and 71.1% for EU and EAC limits). Groundnut had 54.0% and 37.9% of samples above EU and EAC maximum tolerable limits. The lowest proportion of contaminated samples on the other hand was for bambara nut (37.5% and 29.2% for EU and EAC limits, respectively). Aflatoxin exposure in our surveyed population was much higher than previous observations made in Tanzania and also higher than those observed in Western countries such as Australia and the USA. Among children, AFB1 concentration was associated with lower weight for height z scores and weight for age z scores in the univariate model (p < 0.05). In summary, these results indicate the seriousness of aflatoxin contamination in foods commonly consumed in the vulnerable population assessed. Strategies both from the health, trade, and nutrition sectors should therefore be designed and implemented to address aflatoxin and mycotoxin contamination in diets.

Millets Can Have a Major Impact on Improving Iron Status, Hemoglobin Level, and in Reducing Iron Deficiency Anemia-A Systematic Review and Meta-Analysis

The prevalence of iron deficiency anemia is highest among low and middle-income countries. Millets, including sorghum, are a traditional staple in many of these countries and are known to be rich in iron. However, a wide variation in the iron composition of millets has been reported, which needs to be understood in consonance with its bioavailability and roles in reducing anemia. This systematic review and meta-analysis were carried out to analyze the scientific evidence on the bioavailability of iron in different types of millets, processing, and the impact of millet-based food on iron status and anemia. The results indicated that iron levels in the millets used to study iron bioavailability (both in vivo and in vitro) and efficacy varied with the type and variety from 2 mg/100 g to 8 mg/100 g. However, not all the efficacy studies indicated the iron levels in the millets. There were 30 research studies, including 22 human interventions and 8 in vitro studies, included in the meta-analysis which all discussed various outcomes such as hemoglobin level, serum ferritin level, and absorbed iron. The studies included finger millet, pearl millet, teff and sorghum, or a mixture of millets. The results of 19 studies conducted on anaemic individuals showed that there was a significant (p < 0.01) increase in hemoglobin levels by 13.2% following regular consumption (21 days to 4.5 years) of millets either as a meal or drink compared with regular diets where there was only 2.7% increase. Seven studies on adolescents showed increases in hemoglobin levels from 10.8 ± 1.4 (moderate anemia) to 12.2 ± 1.5 g/dl (normal). Two studies conducted on humans demonstrated that consumption of a pearl millet-based meal significantly increased the bioavailable iron (p < 0.01), with the percentage of bioavailability being 7.5 ± 1.6, and provided bioavailable iron of 1 ± 0.4 mg. Four studies conducted on humans showed significant increases in ferritin level (p < 0.05) up to 54.7%. Eight in-vitro studies showed that traditional processing methods such as fermentation and germination can improve bioavailable iron significantly (p < 0.01) by 3.4 and 2.2 times and contributed to 143 and 95% of the physiological requirement of women, respectively. Overall, this study showed that millets can reduce iron deficiency anemia.

A Narrative Review: In-vitro Methods for Assessing Bio-Accessibility/Bioavailability of Iron in Plant-Based Foods

In-vitro measurement has the advantage of rapid and convenient method of screening the iron bioavailability within the range of plant-based foods. It is important to do preliminary screening as it provides information which will be useful to identify promising plant sources of iron before moving to human trials. A review on in-vitro methods of bio-accessibility and bioavailability of iron in plant-based foods including fruits, vegetables, cereals and legumes is entailed here. The review will focus on in-vitro methods of iron bioavailability in plant-based foods and the effects of inhibitors and processing on the iron bioavailability. The variation of the methods and updates on a recent INFOGEST method used to measure the bioavailability of iron in plant-based foods will also be discussed.

The Facilitators and Barriers of Adopting Amylase-Rich Flour to Enhance Complementary Foods in the Kersa District Community of Eastern Ethiopia

Achieving the optimal transition to a family diet over the first two years of life has remained a challenge in Ethiopia. The use of amylase-rich flour (ARF) can improve complementary foods. However, utilisation requires an effective delivery strategy for upskilling the community to use ARF. The aim of this study was to explore facilitators and barriers of cascading ARF skills to improve complementary foods. The study was conducted in Gale Mirga kebele of Kersa district in Eastern Ethiopia in 2016. The study utilised exploratory qualitative research that used participatory action. Focus group discussions (FGDs) were conducted with the Health Development Army (HDA) leaders, religious leaders, and observation of participatory complementary food demonstrations. Cultural acceptability and the presence of HDA structure that supports skill development were identified as key facilitators to ARF use. On the other hand, the potential barriers to expanding ARF skill were lack of sustainability of external skill support for HDA leaders, perceived time constraints, unsuitable demonstration settings, cooking method, and large group size. The indigenous community's knowledge of germination has not been used to improve complementary foods. The universal use of ARF requires integration into the Health Extension Programme (HEP) with support and supervision for HDA leaders.

In Vitro Bioaccessibility and Bioavailability of Iron from Mature and Microgreen Fenugreek, Rocket and Broccoli

Iron deficiency is a global epidemic affecting a third of the world's population. Current efforts are focused on investigating sustainable ways to improve the bioavailability of iron in plant-based diets. Incorporating microgreens into the diet of at-risk groups in populations could be a useful tool in the management and prevention of iron deficiency. This study analysed and compared the mineral content and bioavailability of iron from microgreen and mature vegetables. The mineral content of rocket, broccoli and fenugreek microgreens and their mature counterparts was determined using microwave digestion and ICP-OES. Iron solubility and bioavailability from the vegetables were determined by a simulated gastrointestinal in vitro digestion and subsequent measurement of ferritin in Caco-2 cells as a surrogate marker of iron uptake. Iron contents of mature fenugreek and rocket were significantly higher than those of the microgreens. Mature fenugreek and broccoli showed significantly (p < 0.001) higher bioaccessibility and low-molecular-weight iron than found in the microgreens. Moreover, iron uptake by Caco-2 cells was significantly higher only from fenugreek microgreens than the mature vegetable. While all vegetables except broccoli enhanced FeSO₄ uptake, the response to ferric ammonium citrate (FAC) was inhibitory apart from the mature rocket. Ascorbic acid significantly enhanced iron uptake from mature fenugreek and rocket. Microgreen fenugreek may be bred for a higher content of enhancers of iron availability as a strategy to improve iron nutrition in the populace.

Agricultural and nutritional education interventions for reducing aflatoxin exposure to improve infant and child growth in low- and middle-income countries

BACKGROUND

Aflatoxins are carcinogenic mycotoxins that contaminate many food crops. Maize and groundnuts are prone to aflatoxin contamination, and are the major sources of human exposure to aflatoxins, due to their high intake as staple foods, particularly in low- and middle-income countries (LMICs). Observational studies suggest an association between dietary exposure to aflatoxins during pregnancy and early childhood and linear growth in infants and young children.

OBJECTIVES

To assess the effects on pre- and postnatal growth outcomes when agricultural and nutritional education interventions during the post-harvest period that aim to reduce aflatoxin exposure are compared to usual support or no intervention. We assessed this in infants, children, and pregnant and lactating women at the household or community level in LMICs.

SEARCH METHODS

In July and August 2019, we searched: CENTRAL, MEDLINE, Embase, CINAHL, Web of Science Core Collection, Africa-Wide, LILACS, CAB Abstracts, Agricola, and two trials registers. We also checked the bibliographies of the included studies and contacted relevant mycotoxin organisations and researchers for additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs of agricultural education and nutritional education interventions of any duration, at the household or community level, aimed at reducing aflatoxin intake by infants, children, and pregnant and lactating women, in LMICs during the post-harvest period, compared to no intervention or usual support. We excluded studies that followed participants for less than four weeks. We assessed prespecified prenatal (at birth) and postnatal growth outcomes (during infancy, childhood, and adolescence), with linear growth (as the primary outcome), infectious disease morbidity, and unintended consequences.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility using prespecified criteria, extracted data, and assessed risk of bias of included RCTs. We evaluated the certainty of the evidence using GRADE, and presented the main results in a 'Summary of findings' table.

MAIN RESULTS

We included three recent cluster-RCTs reporting the effects of agricultural education plus post-harvest technologies, compared to usual agricultural support or no intervention. The participants were pregnant women and their children, lactating women and their infants (< 6 months), women of childbearing age, and young children (< 59 months), from rural, subsistence maize-farming communities in Kenya, Zimbabwe, and Tanzania. Two trials randomised villages to the intervention and control groups, including a total of at least 979 mother-child pairs from 60 villages. The third trial randomised 420 households, including 189 mother-child pairs and 231 women of childbearing age. Duration of the intervention and follow-up ranged between five and nine months. Due to risk of attrition bias, the overall risk of bias was unclear in one trial, and high in the other two trials. None of the included studies addressed the effects of nutritional education on pre- and postnatal growth. One trial reported outcomes not prespecified in our review, and we were unable to obtain unpublished growth data from the second trial, even after contacting the authors. The third trial, in lactating women and their infants in Tanzania, reported on the infants' weight-for-age z-score (WAZ) after six months. This trial found that providing agricultural education aimed at changing farmers' post-harvest practices to reduce aflatoxin exposure, by using demonstrations (e.g. handsorting, de-hulling of maize, drying sheets, and insecticides), may improve WAZ in infants from these farmers' households, on average, by 0.57 (95% confidence interval (CI) 0.16 to 0.98; 1 study; 249 participants; very low-certainty evidence), compared to infants from households where the farmers received routine agricultural extension services. Another way of reporting the effect on WAZ is to compare the proportion of underweight infants (WAZ > 2 SD below the reference median value) per group. This trial found that the intervention may reduce the proportion of underweight infants in the intervention households by 6.7% (95% CI -12.6 to -1.4; 249 participants; very low-certainty evidence) compared to control households. No studies reported on unintended effects of agricultural and nutritional education.

AUTHORS' CONCLUSIONS

Evidence on the effects on child growth in LMICs of agricultural or nutritional education interventions that reduce aflatoxin exposure was very limited; no included study reported on linear growth. Very low-certainty evidence suggested that agricultural education aimed at changing farmers' post-harvest practices to reduce aflatoxin exposure by using demonstrations, may result in an increase in WAZ, when compared to usual or no education.

Environmental enteric dysfunction pathways and child stunting: A systematic review

BACKGROUND

Environmental enteric dysfunction (EED) is commonly defined as an acquired subclinical disorder of the small intestine, characterized by villous atrophy and crypt hyperplasia. EED has been proposed to underlie stunted growth among children in developing countries. A collection of biomarkers, organized into distinct domains, has been used to measure different aspects of EED. Here, we examine whether these hypothesized relationships, among EED domains and between each domain and stunting, are supported by data from recent studies.

METHODOLOGY

A systematic literature search was conducted using PubMed, MEDLINE, EMBASE, Web of Science, and CINAHL between January 1, 2010 and April 20, 2017. Information on study objective, design, population, location, biomarkers, and results were recorded, as well as qualitative and quantitative definitions of EED. Biomarkers were organized into five EED domains, and the number of studies that support or do not support relationships among domains and between each domain with stunting were summarized.

RESULTS

There was little evidence to support the pathway from intestinal permeability to microbial translocation and from microbial translocation to stunting, but stronger support existed for the link between intestinal inflammation and systemic inflammation and for intestinal inflammation and stunting. There was conflicting evidence for the pathways from intestinal damage to intestinal permeability and intestinal damage to stunting.

CONCLUSIONS

These results suggest that certain EED biomarkers may require reconsideration, particularly those most difficult to measure, such as microbial translocation and intestinal permeability. We discuss several issues with currently used biomarkers and recommend further analysis of pathogen-induced changes to the intestinal microbiota as a pathway leading to stunting.

Reducing stunting by improving maternal, infant and young child nutrition in regions such as South Asia: evidence, challenges and opportunities

Meeting the high nutrient needs of pregnant and lactating women and their young children in regions such as South Asia is challenging because diets are dominated by staple foods with low nutrient density and poor mineral bioavailability. Gaps in nutritional adequacy in such populations probably date back to the agricultural revolution ~10 000 years ago. Options for improving diets during the first 1000 days include dietary diversification and increased intake of nutrient‐rich foods, improved complementary feeding practices, micronutrient supplements and fortified foods or products specifically designed for these target groups. Evidence from intervention trials indicates that several of these strategies, both prenatal and post‐natal, can have a positive impact on child growth, but results are mixed and a growth response is not always observed. Nutrition interventions, by themselves, may not result in the desired impact if the target population suffers from frequent infection, both clinical and subclinical. Further research is needed to understand the mechanisms underlying both prenatal and post‐natal growth restriction. In the meantime, implementation and rigorous evaluation of integrated interventions that address the multiple causes of stunting is a high priority. These intervention packages should ideally include improved nutrition during both pregnancy and the post‐natal period, prevention and control of prenatal and post‐natal infection and subclinical conditions that restrict growth, care for women and children and stimulation of early child development. In regions such as South Asia, such strategies hold great promise for reducing stunting and enhancing human capital formation.

Increasing Iron Intake of Children through Complementary Foods

Low intake of bioavailable iron from complementary foods is the major cause of the high prevalence of iron-deficiency anemia among children 6 to 24 months of age in developing countries. Increased dietary diversity and traditional food-processing techniques are generally unsuccessful at completely closing the gap between iron intake and needs. Thus, iron-fortified processed complementary foods or home fortification (using powders, crushable tablets, or fat-based products) will be needed in most populations. Several studies have demonstrated that both approaches are efficacious, though there are limited data on effectiveness on a wide scale. The choice of which product to promote may depend on the context, as well as cost constraints. No adverse effects of increasing iron intake through fortification or home fortification of complementary foods have been reported, but large-scale studies that include sufficient numbers of iron-replete children are lacking. Further research is needed to verify the safety of iron-fortification strategies, particularly in malarial areas.

Caterpillar cereal as a potential complementary feeding product for infants and young children: nutritional content and acceptability

Micronutrient deficiency is an important cause of growth stunting. To avoid micronutrient deficiency, the World Health Organization recommends complementary feeding with animal-source foods. However, animal-source foods are not readily available in many parts of the Democratic Republic of Congo (DRC). In such areas, caterpillars are a staple in adult diets and may be suitable for complementary feeding for infants and young children. We developed a cereal made from dried caterpillars and other locally available ingredients (ground corn, palm oil, sugar and salt), measured its macro- and micronutrient contents and evaluated for microbiologic contamination. Maternal and infant acceptability was evaluated among 20 mothers and their 8-10-month-old infants. Mothers were instructed in the preparation of the cereal and asked to evaluate the cereal in five domains using a Likert scale. Mothers fed their infants a 30-g portion daily for 1 week. Infant acceptability was based on cereal consumption and the occurrence of adverse events. The caterpillar cereal contained 132 kcal, 6.9-g protein, 3.8-mg iron and 3.8-mg zinc per 30 g and was free from microbiologic contamination. Mothers' median ratings for cereal characteristics were (5 = like very much): overall impression = 4, taste = 5, smell = 4, texture = 4, colour = 5, and consistency = 4. All infants consumed more than 75% of the daily portions, with five infants consuming 100%. No serious adverse events were reported. We conclude that a cereal made from locally available caterpillars has appropriate macro- and micronutrient contents for complementary feeding, and is acceptable to mothers and infants in the DRC.

The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) Trial: Rationale, Design, and Methods

Child stunting and anemia are intractable public health problems in developing countries and have profound short- and long-term consequences. The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial is motivated by the premise that environmental enteric dysfunction (EED) is a major underlying cause of both stunting and anemia, that chronic inflammation is the central characteristic of EED mediating these adverse effects, and that EED is primarily caused by high fecal ingestion due to living in conditions of poor water, sanitation, and hygiene (WASH). SHINE is a proof-of-concept, 2 × 2 factorial, cluster-randomized, community-based trial in 2 rural districts of Zimbabwe that will test the independent and combined effects of protecting babies from fecal ingestion (factor 1, operationalized through a WASH intervention) and optimizing nutritional adequacy of infant diet (factor 2, operationalized through an infant and young child feeding [IYCF] intervention) on length and hemoglobin at 18 months of age. Within SHINE we will measure 2 causal pathways. The program impact pathway comprises the series of processes and behaviors linking implementation of the interventions with the 2 child health primary outcomes; it will be modeled using measures of fidelity of intervention delivery and household uptake of promoted behaviors and practices. We will also measure a range of household and individual characteristics, social interactions, and maternal capabilities for childcare, which we hypothesize will explain heterogeneity along these pathways. The biomedical pathway comprises the infant biologic responses to the WASH and IYCF interventions that ultimately result in attained stature and hemoglobin concentration at 18 months of age; it will be elucidated by measuring biomarkers of intestinal structure and function (inflammation, regeneration, absorption, and permeability); microbial translocation; systemic inflammation; and hormonal determinants of growth and anemia among a subgroup of infants enrolled in an EED substudy. This article describes the rationale, design, and methods underlying the SHINE trial.

CLINICAL TRIALS REGISTRATION

NCT01824940.

A decade of nutrition research in Africa: assessment of the evidence base and academic collaboration

OBJECTIVE

Malnutrition in Africa has not improved compared with other regions in the world. Investment in the build-up of a strong African research workforce is essential to provide contextual solutions to the nutritional problems of Africa. To orientate this process, we reviewed nutrition research carried out in Africa and published during the last decade.

DESIGN

We assessed nutrition research from Africa published between 2000 and 2010 from MEDLINE and EMBASE and analysed the study design and type of intervention for studies indexed with major MeSH terms for vitamin A deficiency, protein-energy malnutrition, obesity, breast-feeding, nutritional status and food security. Affiliations of first authors were visualised as a network and power of affiliations was assessed using centrality metrics.

SETTING

Africa.

SUBJECTS

Africans, all age groups.

RESULTS

Most research on the topics was conducted in Southern (36%) and Western Africa (34%). The intervention studies (9%; n 95) mainly tested technological and curative approaches to the nutritional problems. Only for papers on protein-energy malnutrition and obesity did lead authorship from Africa exceed that from non-African affiliations. The 10% most powerfully connected affiliations were situated mainly outside Africa for publications on vitamin A deficiency, breast-feeding, nutritional status and food security.

CONCLUSIONS

The development of the evidence base for nutrition research in Africa is focused on treatment and the potential for cross-African networks to publish nutrition research from Africa remains grossly underutilised. Efforts to build capacity for effective nutrition action in Africa will require forging a true academic partnership between African and non-African research institutions.

The challenge of meeting nutrient needs of infants and young children during the period of complementary feeding: an evolutionary perspective

Breast-fed infants and young children need complementary foods with a very high nutrient density (particularly for iron and zinc), especially at ages 6-12 mo. However, in low-income countries, their diet is usually dominated by cereal-based porridges with low nutrient density and poor mineral bioavailability. Complementary feeding diets typically fall short in iron and zinc and sometimes in other nutrients. These gaps in nutritional adequacy of infant diets have likely been a characteristic of human diets since the agricultural revolution ~10,000 y ago. Estimates of nutrient intakes before then, based on hypothetical diets of preagricultural humans, suggest that infants had much higher intakes of key nutrients than is true today and would have been able to meet their nutrient needs from the combination of breast milk and premasticated foods provided by their mothers. Strategies for achieving adequate nutrition for infants and young children in modern times must address the challenge of meeting nutrient needs from largely cereal-based diets.

Dietary exposure to aflatoxin and fumonisin among Tanzanian children as determined using biomarkers of exposure

SCOPE

The study aims to evaluate the status of dietary exposure to aflatoxin and fumonisin in young Tanzanian children, using previously validated biomarkers of exposure.

METHODS AND RESULTS

A total of 148 children aged 12-22 months, were recruited from three geographically distant villages in Tanzania; Nyabula, Kigwa, and Kikelelwa. Plasma aflatoxin-albumin adducts (AF-alb) and urinary fumonisin B1 (UFB1) were measured by ELISA and LC-MS, respectively. AF-alb was detectable in 84% of children, was highest in fully weaned children (p < 0.01) with higher levels being associated with higher maize intake (p < 0.05). AF-alb geometric mean (95% CI) was 43.2 (28.7-65.0), 19.9 (13.5-29.2), and 3.6 (2.8-4.7) pg/mg albumin in children from Kigwa, Nyabula, and Kikelelwa, respectively. UFB1 was detectable in 96% of children and the level was highest in children who had been fully weaned (p < 0.01). The geometric UFB1 mean (95% CI) was 327.2 (217.1-493.0), 211.7 (161.1-278.1), and 82.8 (58.3-117.7) pg/mL in Kigwa, Nyabula, and Kikelelwa, respectively. About 82% of all the children were exposed to both mycotoxins.

CONCLUSION

Young children in Tanzania are chronically exposed to both aflatoxin and fumonisin through contaminated diet, although the level of exposure varies markedly between the three villages studied.

The World Health Organization's global target for reducing childhood stunting by 2025: rationale and proposed actions

In 2012, the World Health Organization adopted a resolution on maternal, infant and young child nutrition that included a global target to reduce by 40% the number of stunted under-five children by 2025. The target was based on analyses of time series data from 148 countries and national success stories in tackling undernutrition. The global target translates to a 3.9% reduction per year and implies decreasing the number of stunted children from 171 million in 2010 to about 100 million in 2025. However, at current rates of progress, there will be 127 million stunted children by 2025, that is, 27 million more than the target or a reduction of only 26%. The translation of the global target into national targets needs to consider nutrition profiles, risk factor trends, demographic changes, experience with developing and implementing nutrition policies, and health system development. This paper presents a methodology to set individual country targets, without precluding the use of others. Any method applied will be influenced by country-specific population growth rates. A key question is what countries should do to meet the target. Nutrition interventions alone are almost certainly insufficient, hence the importance of ongoing efforts to foster nutrition-sensitive development and encourage development of evidence-based, multisectoral plans to address stunting at national scale, combining direct nutrition interventions with strategies concerning health, family planning, water and sanitation, and other factors that affect the risk of stunting. In addition, an accountability framework needs to be developed and surveillance systems strengthened to monitor the achievement of commitments and targets.

Application of in vitro bioaccessibility and bioavailability methods for calcium, carotenoids, folate, iron, magnesium, polyphenols, zinc, and vitamins B(6), B(12), D, and E

A review of in vitro bioaccessibility and bioavailability methods for polyphenols and selected nutrients is presented. The review focuses on in vitro solubility, dialyzability, the dynamic gastrointestinal model (TIM)™, and Caco-2 cell models, the latter primarily for uptake and transport, and a discussion of how these methods have been applied to generate data for a range of nutrients, carotenoids, and polyphenols. Recommendations are given regarding which methods are most justified for answering bioaccessibility or bioavailability related questions for specific nutrients. The need for more validation studies in which in vivo results are compared to in vitro results is also discussed.

Effects of phytases and dehulling treatments on in vitro iron and zinc bioavailability in faba bean (Vicia faba L.) flour and legume fractions

In vitro digestions were performed on faba bean flours with decreased phytate contents and on 2 dephytinized or nondephytinized faba bean fractions, a dehulled faba bean fraction, and a hull fraction with low and high fiber and tannin contents, respectively. In vitro bioavailability iron and zinc was defined as the relative amount of iron and zinc that became soluble after enzymatic treatment. Faba bean samples were sequentially digested with enzymes, including amylase, pepsin, pancreatin, and bile, under certain conditions following the enzymatic degradation procedure. Iron and zinc in vitro bioavailability of whole faba bean flours were significantly improved by phytate degradation, even if the phytate were not all degraded. Total dephytinization of dehulled faba bean led to an obvious increase in iron and zinc in vitro bioavailability, but that of hulls had no effect on either iron or zinc in vitro bioavailability. Fibers and tannins other than phytate are more important in chelating a high proportion of iron and zinc in faba bean hulls.

In vitro solubility of calcium, iron and zinc in relation to phytic acid levels in rice-based consumer products in China

In vitro solubility of calcium, iron and zinc in relation to phytic acid (PA) levels in 30 commercial rice-based foods from China was studied. Solubility of minerals and molar ratios of PA to minerals varied with degrees of processing. In primary products, [PA]/[Ca] values were less than 5 and [PA]/[Fe] and [PA]/[Zn] similarly ranged between 5 and 74, with most values between 20 and 30. [PA]/[mineral] molar ratios in intensively processed products were lower. Solubility of calcium ranged from 0% to 87%, with the lowest in brown rice (12%) and the highest in infant foods (50%). Iron solubility in two-thirds of samples was lower than 30%, and that of zinc narrowly ranged from 6% to 30%. Solubility of minerals was not significantly affected by [PA]/[mineral]. At present, neither primary nor intensively processed rice-based products are good dietary sources of minerals. Improvements should be attempted by dephytinization, mineral fortification or, preferably, combination of both.

Choice of foods and ingredients for moderately malnourished children 6 months to 5 years of age

There is consensus on how to treat severe malnutrition, but there is no agreement on the most cost-effective way to treat infants and young children with moderate malnutrition who consume cereal-dominated diets. The aim of this review is to give an overview of the nutritional qualities of relevant foods and ingredients in relation to the nutritional needs of children with moderate malnutrition and to identify research needs. The following general aspects are covered: energy density, macronutrient content and quality, minerals and vitamins, bioactive substances, antinutritional factors, and food processing. The nutritional values of the main food groups--cereals, legumes, pulses, roots, vegetables, fruits, and animal foods--are discussed. The special beneficial qualities of animal-source foods, which contain high levels of minerals important for growth, high-quality protein, and no antinutrients or fibers, are emphasized. In cereal-dominated diets, the plant foods should be processed to reduce the contents of antinutrients and fibers. Provision of a high fat content to increase energy density is emphasized; however, the content of micronutrients should also be increased to maintain nutrient density. The source of fat should be selected to supply optimal amounts of polyunsaturated fatty acids (PUFAs), especially n-3 fatty acids. Among multiple research needs, the following are highlighted: to identify the minimum quantity of animal foods needed to support acceptable child growth and development, to examine the nutritional gains of reducing contents of antinutrients and fibers in cereal- and legume-based diets, and to examine the role of fat quality, especially PUFA content and ratios, in children with moderate malnutrition.

Development of an Improved Local-Ingredient-Based Complementary Food and Technology Transfer to Rural Housewives

Background

Food technology transfer to rural households, based on local ingredients, is a relevant and sustainable strategy to ensure better nutrition of young children.

Objective

To develop an improved mush based on local ingredients and evaluate the potential for transferring its technology to rural housewives.

Methods

We developed a flour-based food using Alicom software and performed laboratory trials to evaluate its actual nutritional quality. Then we recruited housewives from each of the 27 project villages and trained them in flour production and mush preparation twice daily, 6 days a week, for 26 weeks. Mush was sampled during the training session and at weeks 4, 12, and 22 and evaluated for actual flow distance and dry matter content, which served to estimate energy density and iron and zinc contents.

Results

The laboratory trials reported average energy densities of 103 kcal/100 g, iron contents of 2.6 mg/100 kcal, and zinc contents of 1.2 mg/100 kcal. The average ( ± SD) energy densities of the mush samples obtained during the training session and at weeks 4, 12, and 22 were 103.0 ± 5.6,103.3 ± 5.2,107.9 ± 11.5, and 101.3 ± 8.7 kcal/100 g, respectively. The average iron contents were 2.3 ± 0.5,2.3 ± 0.5,2.6 ± 0.3, and 1.8± 0.8 mg/ 100 kcal, respectively, and the average zinc contents were 1.6± 0.1, 1.6± 0.1,1.7 ± 0.1, and 1.6± 0.2 mg/100 kcal.

Conclusions

Developing a suitable complementary food from local ingredients and educating households in nutrition and use of local products are feasible. Such education should come with measures aimed at improving the accessibility of some ingredients to ensure feasibility and sustainability.

A Review of Interventions Based on Dietary Diversification or Modification Strategies with the Potential to Enhance Intakes of Total and Absorbable Zinc

Dietary diversification or modification has the potential to prevent deficiencies of zinc and other coexisting limiting micronutrients simultaneously, without risk of antagonistic interactions. In this review, we have addressed the following. The first section focuses on strategies with the potential to enhance intake and/or bioavailability of zinc, and includes interventions (with and without nutrition education) based on agriculture, production or promotion of animal-source foods through animal husbandry or aquaculture, and commercial and household processing strategies to enhance zinc absorption. Outcome indicators include intakes of foods or nutrients (although rarely zinc) and, in some cases, zinc status, or zinc-related functional responses. The next two sections address whether dietary diversification or modification can achieve increases in absorbable zinc that are sufficient to enhance zinc status or zinc-related functional responses in breastfed infants and toddlers and in older children and women of reproductive age. Evidence for the impact of dietary diversification or modification on behavior change and on nutritional status in the short and long term, and the possible role of modifying factors (e.g., baseline nutritional status, socioeconomic status, infection, sex, age, and life-stage group) is the emphasis of the next section. The following section highlights the evidence for three potential adverse effects of dietary diversification or modification: aflatoxin contamination from germinated cereals, loss of water-soluble nutrients, and displacement of breastmilk. Finally, an example of a dietary diversification or modification program (Homestead Food Production) developed and implemented by Helen Keller International is given, together with the critical steps needed to scale up dietary diversification or modification for programs and future research needs.

Soy- and rice-based processed complementary food increases nutrient intakes in infants and is equally acceptable with or without added milk powder

Processed complementary foods (PCF) might mitigate several complementary feeding barriers in developing countries. Efficacy trials, however, have not shown substantial improvements in child growth, possibly due to inadequate formative research to assess acceptability and identify pitfalls. Milk powder might improve palatability of PCF but incurs a higher cost. We compared the acceptability of an instant soy-rice PCF without (SR) and with (SRM) milk powder. Best practices for formative evaluation of PCF are not established. We therefore compared findings from randomized trials of SR vs. SRM in 1-d sensory tests (n = 71 mother-infant dyads) vs. Trials of Improved Practices (TIPs), a 2-wk in-home mixed methods evaluation (n = 54 dyads). TIPs included interviews, disappearance rates, observations, and 24-h dietary recalls to assess acceptance, consumption of the 50 g/d ration, and impact on diet. Although mothers preferred SRM to SR in the sensory tests, children in the TIPs consumed >50 g/d of SR (87 +/- 9 g/d) and SRM (89 +/- 8 g/d) with no difference between the foods (P = 0.55). Despite some replacement of family food, energy (574 kJ/d; P < 0.001) and protein (19 g protein/d; P < 0.001) increased in both groups. Mothers' preferences for milk, more sugar in SR, and preparation with hot water were concerns raised in the sensory tests that proved insignificant in TIPs. However, TIPs uncovered new concerns of overconsumption and food safety. We found milk did not improve the acceptability of the soy-rice PCF and recommend TIPs as a useful tool for formative research of PCF interventions.

Traditional food-processing and preparation practices to enhance the bioavailability of micronutrients in plant-based diets

Dietary quality is an important limiting factor to adequate nutrition in many resource-poor settings. One aspect of dietary quality with respect to adequacy of micronutrient intakes is bioavailability. Several traditional household food-processing and preparation methods can be used to enhance the bioavailability of micronutrients in plant-based diets. These include thermal processing, mechanical processing, soaking, fermentation, and germination/malting. These strategies aim to increase the physicochemical accessibility of micronutrients, decrease the content of antinutrients, such as phytate, or increase the content of compounds that improve bioavailability. A combination of strategies is probably required to ensure a positive and significant effect on micronutrient adequacy. A long-term participatory intervention in Malawi that used a range of these strategies plus promotion of the intake of other micronutrient-rich foods, including animal-source foods, resulted in improvements in both hemoglobin and lean body mass and a lower incidence of common infections among intervention compared with control children. The suitability of these strategies and their impact on nutritional status and functional health outcomes need to be more broadly assessed.

Processing of complementary food does not increase hair zinc levels and growth of infants in Kilosa district, rural Tanzania

A community-based, randomized, placebo-controlled, double-blind trial was conducted from March 2001 to March 2002 in Kilosa, a rural district of Morogoro Region in Tanzania. One hundred and fifty-eight infants were selected randomly from lists of local Maternal and Child Health Care Centres and received either processed complementary food (PCF) or unprocessed complementary food (UPCF) from age 6 to 12 months. Processing increased Zn solubility and energy density of the porridge prepared from the complementary food (CF) as determined in vitro. Phytate:Zn molar ratio of the PCF and UPCF was 25·8 and 47·5, respectively. Under the study conditions, the processing of CF did not improve Zn status as measured by hair analysis. No significant correlations were found between hair Zn values and anthropometric measurements. Our findings suggest that processing alone of cereal-based CF may be insufficient to ensure an adequate supply of Zn to improve growth and Zn status of infants. Dietary modification to tackle Zn deficiencies in similar target groups may therefore only be successful when other Zn-rich foods such as meat and fish are included.

Improving the bioavailability of nutrients in plant foods at the household level

Plant foods are the major staples of diets in developing countries, in which the consumption of animal-source foods is often low because of economic and/or religious concerns. However, such plant-based diets are often associated with micronutrient deficits, exacerbated in part by poor micronutrient bioavailability. Diet-related factors in plant foods that affect bioavailability include: the chemical form of the nutrient in food and/or nature of the food matrix; interactions between nutrients and other organic components (e.g. phytate, polyphenols, dietary fibre, oxalic acid, protein, fat, ascorbic acid); pretreatment of food as a result of processing and/or preparation practices. Consequently, household strategies that reduce the content or counteract the inhibiting effects of these factors on micronutrient bioavailability are urgently needed in developing-country settings. Examples of such strategies include: germination, microbial fermentation or soaking to reduce the phytate and polyphenol content of unrefined cereal porridges used for young child feeding; addition of ascorbic acid-containing fruits to enhance non-haem-Fe absorption; heating to destroy heat-labile anti-nutritional factors (e.g. goitrogens, thiaminases) or disrupt carotenoid-protein complexes. Such strategies have been employed in both experimental isotope-absorption and community-based studies. Increases in Fe, Zn and Ca absorption have been reported in adults fed dephytinized cereals compared with cereals containing their native phytate. In community-based studies in rural Malawi improvements in dietary quality and arm-muscle area and reductions in the incidence of anaemia and common infections in young children have been observed.

Iron solubility compared with in vitro digestion-Caco-2 cell culture method for the assessment of iron bioavailability in a processed and unprocessed complementary food for Tanzanian infants (6-12 months)

The Fe solubility test is a commonly used, easy and relatively cheap in vitro tool for predicting Fe bioavailability in food matrices. However, the outcome of a recent field trial comparing the effect on Fe status of Tanzanian infants of processed v. unprocessed complementary foods (CF), with otherwise the same composition, challenged the validity of this test for predicting Fe bioavailability. In the solubility test, significant more soluble Fe was observed in processed compared with unprocessed foods (mean 18.8 (sem 0.21) v. 4.8 (sem 0.23) %; P<0.001). However, in the field trial, no significant difference in Fe status was seen between processed and unprocessed CF groups after 6 months' follow-up. Therefore, twenty-four samples of these CF (twelve processed and twelve unprocessed batches) were analysed in triplicate for Fe availability using an in vitro digestion-Caco-2 cell culture method and results were compared with solubility results. Significantly more soluble Fe was presented to Caco-2 cells in the processed compared with unprocessed samples (mean 11.5 (sem 1.16) v. 8.5 (sem 2.54) %; P=0.028), but proportionally less Fe was taken up by the cells (mean 3.0 (sem 0.40) v. 11.7 (sem 2.22) %; P=0.007). As a net result, absolute Fe uptake was lower (not significantly) in processed compared with unprocessed CF (mean 1.3 (sem 0.16) v. 3.4 (sem 0.83) nmol/mg cell protein; P=0.052). These data clearly demonstrate that the Fe solubility test was not a good indicator of Fe bioavailability in these particular food matrices. In contrast, the results of an in vitro Caco-2 model supported the effects observed in vivo.

Iron and zinc in vitro availability in pearl millet flours (Pennisetum glaucum) with varying phytate, tannin, and fiber contents

Simulations of gastro-intestinal digestion, used to estimate in vitro iron and zinc availability, were performed on two kinds of samples: (i) samples with decreased phytate contents from whole pearl millet flour and (ii) nondephytinized or dephytinized samples from two pearl millet grain fractions, a decorticated fraction with low fiber and tannin contents and a bran fraction with high fiber and tannin contents. Iron and zinc in vitro availabilities of whole pearl millet flour were significantly improved by phytate degradation, even if the IP6 were not all degraded. Total dephytinization of decorticated fraction led to a marked increase in iron and zinc in vitro availabilities, but that of bran fraction had no effect on either iron or zinc in vitro availability. Even if phytates are involved in reducing in vitro iron and zinc availability in pearl millet flour, fibers and tannins play an important role by chelating a high proportion of iron and zinc in grain hulls.