Iron biofortification interventions to improve iron status and functional outcomes

The Effect of Iron-Fortified Lentils on Blood and Cognitive Status among Adolescent Girls in Bangladesh

BACKGROUND

Iron deficiency is highly prevalent in South Asia, especially among women and children in Bangladesh. Declines in cognitive performance are among the many functional consequences of iron deficiency.

OBJECTIVE

We tested the hypothesis that, over the course of a 4-month iron fortification trial, cognitive performance would improve, and that improvement would be related to improvements in iron status.

METHODS

Participants included 359 adolescent girls attending Bangladesh Rural Advancement Committee (BRAC) clubs as a subsample of a larger double-blind, cluster-randomized community trial in which participants were assigned to one of three conditions: a condition in which no lentils were supplied (NL, n = 118, but which had the usual intake of lentils), a control (non-fortified) lentil condition (CL, n = 124), and an iron-fortified lentil condition (FL, n = 117). In the FL and CL conditions, approximately 200 g of cooked lentils were served five days per week for a total of 85 feeding days. In addition to biomarkers of iron status, five cognitive tasks were measured at baseline (BL) and endline (EL): simple reaction time task (SRT), go/no-go task (GNG), attentional network task (ANT), the Sternberg memory search Task (SMS), and a cued recognition task (CRT).

RESULTS

Cognitive performance at EL was significantly better for those in the FL relative to the CL and NL conditions, with this being true for at least one variable in each task, except for the GNG. In addition, there were consistent improvements in cognitive performance for those participants whose iron status improved. Although there were overall declines in iron status from BL to EL, the declines were smallest for those in the FL condition, and iron status was significantly better for those in FL condition at EL, relative to those in the CL and NL conditions.

CONCLUSIONS

the provision of iron-fortified lentils provided a protective effect on iron status in the context of declines in iron status and supported higher levels of cognitive performance for adolescent girls at-risk of developing iron deficiency.

Review of intervention products for use in the prevention and control of anemia

Anemia remains a major public health problem, especially in low- and middle-income countries. The World Health Organization recommends several interventions to prevent and manage anemia in vulnerable population groups, including young children, menstruating adolescent girls and women, and pregnant and postpartum women. Daily iron supplementation reduces the risk of anemia in infants, children, and pregnant women, and intermittent iron supplementation reduces anemia risk in menstruating girls and women. Micronutrient powders reduce the risk of anemia in children. Fortifying wheat flour with iron reduces the risk of anemia in the overall population, whereas the effect of fortifying maize flour and rice is still uncertain. Regarding non-nutrition-related interventions, malaria treatment and deworming have been reported to decrease anemia prevalence. Promising interventions to prevent anemia include vitamin A supplementation, multiple micronutrient supplementation for pregnant women, small-quantity lipid-based supplements, and fortification of salt with iodine and iron. Future research could address the efficacy and safety of different iron supplementation formulations, identify the most bioavailable form of iron for fortification, examine adherence to supplementation regimens and fortification standards, and investigate the effectiveness of integrating micronutrient, helminth, and malaria control programs.

Key Nutrients for Optimal Blood Glucose Control and Mental Health in Individuals with Diabetes: A Review of the Evidence

Diabetes is associated with an increased risk of mental disorders, including depression, anxiety, and cognitive decline. Mental disorders can also contribute to the development of diabetes through various mechanisms including increased stress, poor self-care behaviors, and adverse effects on glucose metabolism. Consequently, individuals suffering from either of these conditions frequently experience comorbidity with the other. Nutrition plays an important role in both diabetes and mental health disorders including depression and anxiety. Deficiencies in specific nutrients such as omega-3 fatty acids, vitamin D, B vitamins, zinc, chromium, magnesium, and selenium have been implicated in the pathogenesis of both diabetes and mental disorders. While the impact of nutrition on the progression and control of diabetes and mental disorders is broadly acknowledged, there is a notable knowledge gap concerning the implications of distinct nutrients in preventing and mitigating symptoms of both conditions when they coexist. The aim of this study was to examine the role of nutrition in improving glucose homeostasis and promoting mental well-being among individuals with diabetes. Further, we evaluated the preventive or delaying effects of key nutrients on the simultaneous manifestation of these conditions when one of them is present. Our findings indicated that the use of personalized dietary interventions and targeted nutrient supplementation can improve metabolic and mental health outcomes in patients with type 2 diabetes.

Development of Iron Status Measures during Youth: Associations with Sex, Neighborhood Socioeconomic Status, Cognitive Performance, and Brain Structure

BACKGROUND

Iron is essential to brain function, and iron deficiency during youth may adversely impact neurodevelopment. Understanding the developmental time course of iron status and its association with neurocognitive functioning is important for identifying windows for intervention.

OBJECTIVES

This study aimed to characterize developmental change in iron status and understand its association with cognitive performance and brain structure during adolescence using data from a large pediatric health network.

METHODS

This study included a cross-sectional sample of 4899 participants (2178 males; aged 8-22 y at the time of participation, M [SD] = 14.24 [3.7]) who were recruited from the Children's Hospital of Philadelphia network. Prospectively collected research data were enriched with electronic medical record data that included hematological measures related to iron status, including serum hemoglobin, ferritin, and transferrin (33,015 total samples). At the time of participation, cognitive performance was assessed using the Penn Computerized Neurocognitive Battery, and brain white matter integrity was assessed using diffusion-weighted MRI in a subset of individuals.

RESULTS

Developmental trajectories were characterized for all metrics and revealed that sex differences emerged after menarche such that females had reduced iron status relative to males [all R2partial > 0.008; all false discovery rates (FDRs) < 0.05]. Higher socioeconomic status was associated with higher hemoglobin concentrations throughout development (R2partial = 0.005; FDR < 0.001), and the association was greatest during adolescence. Higher hemoglobin concentrations were associated with better cognitive performance during adolescence (R2partial = 0.02; FDR < 0.001) and mediated the association between sex and cognition (mediation effect = -0.107; 95% CI: -0.191, -0.02). Higher hemoglobin concentration was also associated with greater brain white matter integrity in the neuroimaging subsample (R2partial = 0.06, FDR = 0.028).

CONCLUSIONS

Iron status evolves during youth and is lowest in females and individuals of low socioeconomic status during adolescence. Diminished iron status during adolescence has consequences for neurocognition, suggesting that this critical period of neurodevelopment may be an important window for intervention that has the potential to reduce health disparities in at-risk populations.

Can consumption of local micronutrient- and absorption enhancer-rich plant foods together with starchy staples improve bioavailable iron and zinc in diets of at-risk African populations?

Iron and zinc deficiencies remain prevalent in developing countries, often due to monotonous starchy diets that are low in bioavailable minerals. This review addresses the question as to whether consumption of starchy staple foods in Africa together with micronutrient-dense and absorption enhancer-rich plant foods can enhance iron and zinc bioavailability in the diets of at-risk populations. While green leafy vegetables (GLVs) fortification of starchy staples can improve mineral contents, especially iron, it may not improve bioavailable iron and zinc, due to GLVs' high contents of mineral absorption inhibitors, notably polyphenols, phytate and calcium. Fruits, although low in minerals, could improve bioavailable iron and zinc in the staples because of their high ascorbic and citric acid and/or β-carotene contents, which can form soluble chelates with the minerals. More human studies are needed to establish whether such a technology or fortification strategy can improve bioavailable iron and zinc in African-type plant-based diets.

Shooting shadows: India's struggle to reduce the burden of anaemia

Despite several efforts by the Government of India, the national burden of anaemia remains high and its growing prevalence (between 2015-2016 and 2019-2021) is concerning to India's public health system. This article reviews existing food-based and clinical strategies to mitigate the anaemia burden and why they are premature and insufficient. In a context where multiple anaemia control programmes are in play, this article proposes a threefold strategy for consideration. First, except the Comprehensive National Nutrition Survey, 2016-2018, which measured Hb concentration among children and adolescents aged 1-19 years using venous blood samples, all national surveys use capillary blood samples to determine Hb levels, which could be erroneous. The Indian government should prioritise conducting a nationwide survey for estimating the burden of anaemia and its clinical determinants for all age groups using venous blood samples. Second, without deciding the appropriate dose of Fe needed for an individual, food fortification programmes that are often compounded with layering of other micronutrients could be harmful and further research on this issue is needed. Same is true for the pharmacological intervention of Fe tablet or syrup supplementation programmes, which is given to individuals without assessing its need. In addition, there is a dire need for robust research to understand both the long-term benefit and side effects of Fe supplementation programmes. Third and final, the WHO is in process of reviewing the Hb threshold for defining anaemia, therefore the introduction of new anaemia control programmes should be restrained.

Biofortification to avoid malnutrition in humans in a changing climate: Enhancing micronutrient bioavailability in seed, tuber, and storage roots

Malnutrition results in enormous socio-economic costs to the individual, their community, and the nation's economy. The evidence suggests an overall negative impact of climate change on the agricultural productivity and nutritional quality of food crops. Producing more food with better nutritional quality, which is feasible, should be prioritized in crop improvement programs. Biofortification refers to developing micronutrient -dense cultivars through crossbreeding or genetic engineering. This review provides updates on nutrient acquisition, transport, and storage in plant organs; the cross-talk between macro- and micronutrients transport and signaling; nutrient profiling and spatial and temporal distribution; the putative and functionally characterized genes/single-nucleotide polymorphisms associated with Fe, Zn, and β-carotene; and global efforts to breed nutrient-dense crops and map adoption of such crops globally. This article also includes an overview on the bioavailability, bioaccessibility, and bioactivity of nutrients as well as the molecular basis of nutrient transport and absorption in human. Over 400 minerals (Fe, Zn) and provitamin A-rich cultivars have been released in the Global South. Approximately 4.6 million households currently cultivate Zn-rich rice and wheat, while ~3 million households in sub-Saharan Africa and Latin America benefit from Fe-rich beans, and 2.6 million people in sub-Saharan Africa and Brazil eat provitamin A-rich cassava. Furthermore, nutrient profiles can be improved through genetic engineering in an agronomically acceptable genetic background. The development of "Golden Rice" and provitamin A-rich dessert bananas and subsequent transfer of this trait into locally adapted cultivars are evident, with no significant change in nutritional profile, except for the trait incorporated. A greater understanding of nutrient transport and absorption may lead to the development of diet therapy for the betterment of human health.

Child Health, Agriculture and Integrated Nutrition (CHAIN): protocol for a randomised controlled trial of improved infant and young child feeding in rural Zimbabwe

INTRODUCTION

Over one-quarter of children in sub-Saharan Africa are stunted; however, commercial supplements only partially meet child nutrient requirements, cannot be sustainably produced, and do not resolve physiological barriers to adequate nutrition (eg, inflammation, microbiome dysbiosis and metabolic dysfunction). Redesigning current infant and young child feeding (IYCF) interventions using locally available foods to improve intake, uptake and utilisation of nutrients could ameliorate underlying pathogenic pathways and improve infant growth during the critical period of complementary feeding, to reduce the global burden of stunting.

METHODS AND ANALYSIS

Child Health Agriculture Integrated Nutrition is an open-label, individual household randomised trial comparing the effects of IYCF versus 'IYCF-plus' on nutrient intake during infancy. The IYCF intervention comprises behaviour change modules to promote infant nutrition delivered by community health workers, plus small-quantity lipid-based nutrient supplements from 6 to 12 months of age which previously reduced stunting at 18 months of age by ~20% in rural Zimbabwe. The 'IYCF-plus' intervention provides these components plus powdered NUA-45 biofortified sugar beans, whole egg powder, moringa leaf powder and provitamin A maize. The trial will enrol 192 infants between 5 and 6 months of age in Shurugwi district, Zimbabwe. Research nurses will collect data plus blood, urine and stool samples at baseline (5-6 months of age) and endline (9-11 months of age). The primary outcome is energy intake, measured by multipass 24-hour dietary recall at 9-11 months of age. Secondary outcomes include nutrient intake, anthropometry and haemoglobin concentration. Nested laboratory substudies will evaluate the gut microbiome, environmental enteric dysfunction, metabolic phenotypes and innate immune function. Qualitative substudies will explore the acceptability and feasibility of the IYCF-plus intervention among participants and community stakeholders, and the effects of migration on food production and consumption.

ETHICS AND DISSEMINATION

This trial is registered at ClinicalTrials.gov (NCT04874688) and was approved by the Medical Research Council of Zimbabwe (MRCZ/A/2679) with the final version 1.4 approved on 20 August 2021, following additional amendments. Dissemination of trial results will be conducted through the Community Engagement Advisory Board in the study district and through national-level platforms.

TRIAL REGISTRATION NUMBER

NCT04874688.

Improving nutrition through biofortification-A systematic review

Nutritious foods are essential for human health and development. However, malnutrition and hidden hunger continue to be a challenge globally. In most developing countries, access to adequate and nutritious food continues to be a challenge. Although hidden hunger is less prevalent in developed countries compared to developing countries where iron (Fe) and zinc (Zn) deficiencies are common. The United Nations (UN) 2nd Sustainable Development Goal was set to eradicate malnutrition and hidden hunger. Hidden hunger has led to numerous cases of infant and maternal mortalities, and has greatly impacted growth, development, cognitive ability, and physical working capacity. This has influenced several countries to develop interventions that could help combat malnutrition and hidden hunger. Interventions such as dietary diversification and food supplementation are being adopted. However, fortification but mainly biofortification has been projected to be the most sustainable solution to malnutrition and hidden hunger. Plant-based foods (PBFs) form a greater proportion of diets in certain populations; hence, fortification of PBFs is relevant in combating malnutrition and hidden hunger. Agronomic biofortification, plant breeding, and transgenic approaches are some currently used strategies in food crops. Crops such as cereals, legumes, oilseeds, vegetables, and fruits have been biofortified through all these three strategies. The transgenic approach is sustainable, efficient, and rapid, making it suitable for biofortification programs. Omics technology has also been introduced to improve the efficiency of the transgenic approach.

Small and Medium Enterprises' Perspectives on Food Fortification Amid the Growing Burden of Malnutrition

The need for a profound food system transformation has never been greater. The growing burden of malnutrition has become the new normal, with two billion people who are overweight, over 140 million children under five who are stunted and over two billion people affected by hidden hunger. Food fortification has been recognized as a cost-effective strategy to address micronutrient deficiencies. Small and medium enterprises (SMEs) play a strategic role in the food supply chain in low- and middle-income countries, accounting for over 80% of food sales. It is therefore critical to create an enabling environment to facilitate SMEs' involvement in food fortification practices as a potential solution to tackle all forms of malnutrition. This review highlights SMEs' relevance as agents of change in the food system through food fortification practices and their indirect yet key role in producing nutritious, tasty and affordable foods. It discusses their challenges (e.g., access to long-term finance, sustainable technical assistance, limited capacity), presents solutions and discusses how different actors can help SMEs to overcome these challenges. Furthermore, it presents a relevant public-private partnership case study to demonstrate how SMEs can address the growing burden of malnutrition through food fortification practices, nutrient profiling schemes and demand generation.

Dietary Approaches to Iron Deficiency Prevention in Childhood-A Critical Public Health Issue

Iron is an essential nutrient, and individual iron status is determined by the regulation of iron absorption, which is driven by iron requirements. Iron deficiency (ID) disproportionately affects infants, children, and adolescents, particularly those who live in areas with unfavorable socioeconomic conditions. The main reason for this is that diet provides insufficient bioavailable iron to meet their needs. The consequences of ID include poor immune function and response to vaccination, and moderate ID anemia is associated with depressed neurodevelopment and impaired cognitive and academic performances. The persistently high prevalence of ID worldwide leads to the need for effective measures of ID prevention. The main strategies include the dietary diversification of foods with more bioavailable iron and/or the use of iron-fortified staple foods such as formula or cereals. However, this strategy may be limited due to its cost, especially in low-income countries where biofortification is a promising approach. Another option is iron supplementation. In terms of health policy, the choice between mass and targeted ID prevention depends on local conditions. In any case, this remains a critical public health issue in many countries that must be taken into consideration, especially in children under 5 years of age.

A randomized trial of iron- and zinc-biofortified pearl millet-based complementary feeding in children aged 12 to 18 months living in urban slums

BACKGROUND & AIMS

Biofortification of staple crops with higher levels of micronutrients via traditional breeding methods is a sustainable strategy and can possibly complement fortification and other interventions to target micronutrient deficiencies in low resource settings, particularly among vulnerable populations such as children. We aimed to determine if iron- and zinc-biofortified pearl millet (FeZnPM, Dhanashakti, ICTP-8203Fe)-based complementary feeding improves nutritional status, including iron biomarkers and growth, in children living in urban slums of Mumbai.

METHODS

We conducted a randomized controlled trial of FeZnPM among 223 children aged 12-18 months who were not severely anemic at baseline (hemoglobin ≥9.0 g/dL). Children were randomized to receive either FeZnPM or conventional non-biofortified pearl millet (CPM) daily for 9 months. Iron status (hemoglobin, serum ferritin), plasma zinc, and anthropometric indicators (length, weight, mid-upper arm circumference, triceps and subscapular skinfolds) were evaluated at enrollment and throughout the trial. World Health Organization (WHO) anthropometric z-scores were calculated using WHO growth standards. Primary outcomes were hemoglobin and serum ferritin concentrations, and growth, defined as WHO z-scores. An intent to treat approach was used for analyses. We used the Hodges-Lehmann-Sen test to assess the change in primary outcomes between baseline and the last visit and report corresponding 95% confidence intervals.

RESULTS

At baseline, 67.7% of children were anemic (hemoglobin <11.0 g/dL) and 59.6% were iron deficient (serum ferritin <12.0 μg/L). FeZnPM did not significantly increase iron biomarkers or improve growth, compared to CPM. In subgroup analyses, FeZnPM improved hemoglobin concentrations in male children, and in children with iron deficiency or iron depletion (serum ferritin <25.0 μg/L) at baseline, relative to CPM.

CONCLUSIONS

Daily consumption of FeZnPM-based complementary foods did not significantly impact iron and zinc status or growth in children living in Mumbai's urban slums. However, the intervention significantly improved hemoglobin concentrations among male children and among individuals who were iron-deficient or iron-depleted at baseline.

TRIAL REGISTRATION

This trial is registered with Clinicaltrials.gov (ID: NCT02233764), and Clinical Trials Registry of India (ID: REF/2014/10/007731).

Iron Status, Anemia, and Iron Interventions and Their Associations with Cognitive and Academic Performance in Adolescents: A Systematic Review

In adolescents, iron-deficiency anemia is the leading cause of disability-adjusted life years lost. The World Health Organization recommends delivering iron supplementation through school-based platforms, requiring partnerships with the education sector. This anemia-reduction intervention is valued for the perceived benefits of improved learning and school performance. This article aims to systematically review the available evidence on the relationship between iron status and anemia and impacts of iron interventions on cognitive and academic performance in adolescents. Fifty studies were included: n = 26 cross-sectional and n = 24 iron-containing interventions. Our review suggests that iron status and anemia may be associated with academic performance in some contexts and that iron supplementation during adolescence may improve school performance, attention, and concentration. However, nearly all supplementation trials were judged to have moderate or high risk of bias. We did not find evidence suggesting that iron status and anemia influenced or were associated with attention, intelligence, nor memory in adolescents. Further, iron supplementation did not improve memory and recall or intelligence. Overall, more high-quality research is needed to guide programmers and policy makers to understand the relationships between anemia and educational performance and the potential impacts of iron interventions, which effectively reduce anemia, on adolescents’ learning and school performance.

Effects of Physical Activity and Micronutrients on Cognitive Performance in Children Aged 6 to 11 Years: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background and Objectives: Cognitive performance is essential for children, given this is a critical stage of brain growth and development. This systematic review and meta-analysis aimed to ascertain if physical activity or micronutrients impact cognitive performance in children. Materials and Methods: Electronic databases (PubMed and Scopus^®) were searched for relevant articles published between 2012 and 2021. We emphasized randomized controlled trials (RCTs) that examined the effect of physical activity and micronutrients on cognitive performance. Data from eligible studies were gathered and evaluated using random-, fixed- or pooled-effects models with 95% confidence intervals (95% CI). Results: Physical activity appeared to improve both Mathematics (d = 1.12, 95% CI: 0.56, 1.67) and attention (d = 0.65, 95% CI: 0.15, 1.14) performances. The micronutrient vitamin B12 had a positive effect on Mathematics (d = 2.39, 95% CI: 0.79, 3.98), English (d = 5.29, 95% CI: 2.76, 7.83), Geography (d = 5.29, 95% CI: 2.76, 7.83), Science (d = 3.39, 95% CI: 2.62, 4.16) and Arts (d = 3.32, 95% CI: 1.84, 4.79). Zinc was found to positively affect English (d = 3.78, 95% CI: 0.44, 7.13), Geography (d = 4.77, 95% CI: 0.56, 8.98) and Arts (d = 2.39, CI: 0.33, 4.45). Iron positively affected Mathematics (d = 1.29, 95% CI: 0.54, 2.06), English (d = 1.29, 95% CI: 0.44, 7.13), Geography (d = 4.77, 95% CI: 0.56, 8.98) and Arts (d = 2.39, 95% CI: 0.33, 4.45). Conclusions: A more comprehensive intervention with a specific dose/level of physical activity, an increased range of cognitive performance, and a well-designed study design that accounts for dietary intake and other health outcomes are required for future studies.

Consumption of Sinlek Rice Drink Improved Red Cell Indices in Anemic Elderly Subjects

Iron fortifications are used for the treatment of iron-deficiency anemia; however, iron dosing may cause oxidative damage to the gut lumen. Thai Sinlek rice is abundant in iron and contains phytochemicals. We aimed at evaluating the effect of an iron-rice (IR) hydrolysate drink (100 mL/serving) on neurological function, red cell indices and iron status in elders. Healthy elderly subjects were divided into three non-anemic groups and one anemic group. The non-anemic groups consumed one WR (2 mg iron/serving) and two IR drinks (15 and 27 mg iron/serving) (groups A, B and D, respectively), while the anemic group consumed one IR drink (15 mg iron serving) (group C) every day for 30 days. There were no significant differences in the MMSE Thai 2002 and PHQ9 test scores for members of all groups, while the nutrition scores and body weight values of group D subjects were significantly increased. Hemoglobin (Hb) and mean corpuscular hemoglobin concentrations increased significantly only in group C. Serum iron and transferrin saturation levels tended to increase in group A, while these levels were decreased in members of group C. Serum antioxidant activity levels were increased in all groups, and were highest in group C. Thus, consumption of an IR drink for 15 days functioned to increase Hb and antioxidant capacity levels in anemic elders.

Perspective: Putting the youngest among us into the nutrition "call for action" for food fortification strategies

Adequate iron intake is essential for optimal child development, but iron deficiency and anemia among infants and young children are widespread in low- and middle-income countries. Large-scale food fortification strategies hold great promise for reducing micronutrient deficiencies; however, for children <2 y of age, the impact of such strategies is limited because their intake of staple foods is relatively low and fortification levels are targeted at the adult population. Iron supplementation, iron fortification of foods targeted to infants, and point-of-use fortification with iron-containing products such as multiple micronutrient powders (MNPs) and small-quantity lipid-based nutrient supplements are evidence-based approaches recommended to reduce anemia among infants and young children when used in the right context. Since 2003, the WHO, with support from UNICEF, has recommended the use of MNPs to control iron deficiency. However, the percentage of children with anemia has changed very little over the past 10 y. Five years ago the UN declared a decade of action on nutrition, including World Health Assembly (WHA) targets for maternal, infant, and young child nutrition, yet the WHA set no anemia targets for children. In July 2020 the leaders of 4 UN agencies issued a call for action to protect children's right to nutrition in the face of the COVID-19 pandemic and beyond. Given persistently high rates of anemia among young children, the negative developmental impact, the challenge of meeting iron needs from typical complementary food diets, and the availability of successful evidence-based fortification strategies for this age group, we encourage planners, speakers, and donors at this year's UN Food Systems Summit and the Tokyo Nutrition for Growth Summit to 1) call for the WHA to set anemia targets for infants and young children and 2) promote investment in evidence-based interventions to improve the iron status of young children.

Nutrition-specific interventions for preventing and controlling anaemia throughout the life cycle: an overview of systematic reviews

BACKGROUND

Anaemia is a prevalent health problem worldwide. Some types are preventable or controllable with iron supplementation (pills or drops), fortification (sprinkles or powders containing iron added to food) or improvements to dietary diversity and quality (e.g. education or counselling).

OBJECTIVES

To summarise the evidence from systematic reviews regarding the benefits or harms of nutrition-specific interventions for preventing and controlling anaemia in anaemic or non-anaemic, apparently healthy populations throughout the life cycle.

METHODS

In August 2020, we searched MEDLINE, Embase and 10 other databases for systematic reviews of randomised controlled trials (RCTs) in anaemic or non-anaemic, apparently healthy populations. We followed standard Cochrane methodology, extracting GRADE ratings where provided. The primary outcomes were haemoglobin (Hb) concentration, anaemia, and iron deficiency anaemia (IDA); secondary outcomes were iron deficiency (ID), severe anaemia and adverse effects (e.g. diarrhoea, vomiting).

MAIN RESULTS

We included 75 systematic reviews, 33 of which provided GRADE assessments; these varied between high and very low. Infants (6 to 23 months; 13 reviews) Iron supplementation increased Hb levels and reduced the risk of anaemia and IDA in two reviews. Iron fortification of milk or cereals, multiple-micronutrient powder (MMNP), home fortification of complementary foods, and supplementary feeding increased Hb levels and reduced the risk of anaemia in six reviews. In one review, lipid-based nutrient supplementation (LNS) reduced the risk of anaemia. In another, caterpillar cereal increased Hb levels and IDA prevalence. Food-based strategies (red meat and fortified cow's milk, beef) showed no evidence of a difference (1 review). Preschool and school-aged children (2 to 10 years; 8 reviews) Daily or intermittent iron supplementation increased Hb levels and reduced the risk of anaemia and ID in two reviews. One review found no evidence of difference in Hb levels, but an increased risk of anaemia and ID for the intermittent regime. All suggested that zinc plus iron supplementation versus zinc alone, multiple-micronutrient (MMN)-fortified beverage versus control, and point-of-use fortification of food with iron-containing micronutrient powder (MNP) versus placebo or no intervention may increase Hb levels and reduce the risk of anaemia and ID. Fortified dairy products and cereal food showed no evidence of a difference on the incidence of anaemia (1 review). Adolescent children (11 to 18 years; 4 reviews) Compared with no supplementation or placebo, five types of iron supplementation may increase Hb levels and reduce the risk of anaemia (3 reviews). One review on prevention found no evidence of a difference in anaemia incidence on iron supplementation with or without folic acid, but Hb levels increased. Another suggested that nutritional supplementation and counselling reduced IDA. One review comparing MMN fortification with no fortification observed no evidence of a difference in Hb levels. Non-pregnant women of reproductive age (19 to 49 years; 5 reviews) Two reviews suggested that iron therapy (oral, intravenous (IV), intramuscular (IM)) increased Hb levels; one showed that iron folic acid supplementation reduced anaemia incidence; and another that daily iron supplementation with or without folic acid or vitamin C increased Hb levels and reduced the risk of anaemia and ID. No review reported interventions related to fortification or dietary diversity and quality. Pregnant women of reproductive age (15 to 49 years; 23 reviews) One review apiece suggested that: daily iron supplementation with or without folic acid increased Hb levels in the third trimester or at delivery and in the postpartum period, and reduced the risk of anaemia, IDA and ID in the third trimester or at delivery; intermittent iron supplementation had no effect on Hb levels and IDA, but increased the risk of anaemia at or near term and ID, and reduced the risk of side effects; vitamin A supplementation alone versus placebo, no intervention or other micronutrient might increase maternal Hb levels and reduce the risk of maternal anaemia; MMN with iron and folic acid versus placebo reduced the risk of anaemia; supplementation with oral bovine lactoferrin versus oral ferrous iron preparations increased Hb levels and reduced gastrointestinal side effects; MNP for point-of-use fortification of food versus iron and folic acid supplementation might decrease Hb levels at 32 weeks' gestation and increase the risk of anaemia; and LNS versus iron or folic acid and MMN increased the risk of anaemia. Mixed population (all ages; 22 reviews) Iron supplementation versus placebo or control increased Hb levels in healthy children, adults, and elderly people (4 reviews). Hb levels appeared to increase and risk of anaemia and ID decrease in two reviews investigating MMN fortification versus placebo or no treatment, iron fortified flour versus control, double fortified salt versus iodine only fortified salt, and rice fortification with iron alone or in combination with other micronutrients versus unfortified rice or no intervention. Each review suggested that fortified versus non-fortified condiments or noodles, fortified (sodium iron ethylenediaminetetraacetate; NaFeEDTA) versus non-fortified soy sauce, and double-fortified salt versus control salt may increase Hb concentration and reduce the risk of anaemia. One review indicated that Hb levels increased for children who were anaemic or had IDA and received iron supplementation, and decreased for those who received dietary interventions. Another assessed the effects of foods prepared in iron pots, and found higher Hb levels in children with low-risk malaria status in two trials, but no difference when comparing food prepared in non-cast iron pots in a high-risk malaria endemicity mixed population. There was no evidence of a difference for adverse effects. Anaemia and malaria prevalence were rarely reported. No review focused on women aged 50 to 65 years plus or men (19 to 65 years plus).

AUTHORS' CONCLUSIONS

Compared to no treatment, daily iron supplementation may increase Hb levels and reduce the risk of anaemia and IDA in infants, preschool and school-aged children and pregnant and non-pregnant women. Iron fortification of foods in infants and use of iron pots with children may have prophylactic benefits for malaria endemicity low-risk populations. In any age group, only a limited number of reviews assessed interventions to improve dietary diversity and quality. Future trials should assess the effects of these types of interventions, and consider the requirements of different populations.

Scaling Up Delivery of Biofortified Staple Food Crops Globally: Paths to Nourishing Millions

BACKGROUND

Micronutrient deficiencies affect over one quarter of the world's population. Biofortification is an evidence-based nutrition strategy that addresses some of the most common and preventable global micronutrient gaps and can help improve the health of millions of people. Since 2013, HarvestPlus and a consortium of collaborators have made impressive progress in the enrichment of staple crops with essential micronutrients through conventional plant breeding.

OBJECTIVE

To review and highlight lessons learned from multiple large-scale delivery strategies used by HarvestPlus to scale up biofortification across different country and crop contexts.

RESULTS

India has strong public and private sector pearl millet breeding programs and a robust commercial seed sector. To scale-up pearl millet, HarvestPlus established partnerships with public and private seed companies, which facilitated the rapid commercialization of products and engagement of farmers in delivery activities. In Nigeria, HarvestPlus stimulated the initial acceptance and popularization of vitamin A cassava using a host of creative approaches, including "crowding in" delivery partners, innovative promotional programs, and development of intermediate raw material for industry and novel food products. In Uganda, orange sweet potato (OSP) is a traditional subsistence crop. Due to this, and the lack of formal seed systems and markets, HarvestPlus established a network of partnerships with community-based nongovernmental organizations and vine multipliers to popularize and scale-up delivery of OSP.

CONCLUSIONS

Impact of biofortification ultimately depends on the development of sustainable markets for biofortified seeds and products. Results illustrate the need for context-specific, innovative solutions to promote widespread adoption.

Effectiveness of Food Fortification in Improving Nutritional Status of Mothers and Children in Indonesia

Food fortification programs have been conducted in several countries to overcome micronutrient deficiency and related problems with various degrees of effectiveness. Available information regarding the success of food fortification programs in some developing countries, including Indonesia, is still limited. Thus, this study conducts a systematic review of the effects of food fortification of mothers and children using biochemical and anthropometric measures focusing on linear growth. Three databases were used in the literature search, namely PubMed, Science Direct and Google Scholar. Fifteen articles were included for analysis from 517 studies found consisting of Indonesian and English articles published from 2000 to June 2020. Fortification of iron, vitamin A, and iodine can increase the level of hemoglobin, serum ferritin, and serum retinol and median urine iodine excretion, especially in toddlers and schoolchildren. However, multinutrient fortification interventions were associated with various effects on hemoglobin, serum ferritin, and serum retinol but a positive association was found with linear growth indicators in the form of body length for age. The effectiveness of food fortification in reducing the prevalence of stunting still needs more and stronger evidence through studies with large sample size and longer duration.

Iron

Iron deficiency anemia affects approximately one-third of the world's population, and about half the cases are due to iron deficiency. The latest research on iron metabolism published in original articles and systematic reviews is described, and references to recent reviews provided. The topics include dietary sources and bioavailability, iron homeostasis, functions of iron in the body, and biomarkers of status. The consequences of iron deficiency and excess are discussed, with particular focus on vulnerable populations such as pregnant women, infants and the elderly. The newest dietary recommendations, including dietary reference values and food based dietary guidelines, are briefly summarized, followed by the latest developments in food fortification and iron supplementation.

Importance of the Rhizosphere Microbiota in Iron Biofortification of Plants

Increasing the iron content of plant products and iron assimilability represents a major issue for human nutrition and health. This is also a major challenge because iron is not readily available for plants in most cultivated soils despite its abundance in the Earth's crust. Iron biofortification is defined as the enhancement of the iron content in edible parts of plants. This biofortification aims to reach the objectives defined by world organizations for human nutrition and health while being environment friendly. A series of options has been proposed to enhance plant iron uptake and fight against hidden hunger, but they all show limitations. The present review addresses the potential of soil microorganisms to promote plant iron nutrition. Increasing knowledge on the plant microbiota and plant-microbe interactions related to the iron dynamics has highlighted a considerable contribution of microorganisms to plant iron uptake and homeostasis. The present overview of the state of the art sheds light on plant iron uptake and homeostasis, and on the contribution of plant-microorganism (plant-microbe and plant-plant-microbe) interactions to plant nutritition. It highlights the effects of microorganisms on the plant iron status and on the co-occurring mechanisms, and shows how this knowledge may be valued through genetic and agronomic approaches. We propose a change of paradigm based on a more holistic approach gathering plant and microbial traits mediating iron uptake. Then, we present the possible applications in plant breeding, based on plant traits mediating plant-microbe interactions involved in plant iron uptake and physiology.

The Central Role of Iron in Human Nutrition: From Folk to Contemporary Medicine

Iron is a fundamental element in human history, from the dawn of civilization to contemporary days. The ancients used the metal to shape tools, to forge weapons, and even as a dietary supplement. This last indication has been handed down until today, when martial therapy is considered fundamental to correct deficiency states of anemia. The improvement of the martial status is mainly targeted with dietary supplements that often couple diverse co-factors, but other methods are available, such as parenteral preparations, dietary interventions, or real-world approaches. The oral absorption of this metal occurs in the duodenum and is highly dependent upon its oxidation state, with many absorption influencers possibly interfering with the intestinal uptake. Bone marrow and spleen represent the initial and ultimate step of iron metabolism, respectively, and the most part of body iron circulates bound to specific proteins and mainly serves to synthesize hemoglobin for new red blood cells. Whatever the martial status is, today’s knowledge about iron biochemistry allows us to embrace exceedingly personalized interventions, which however owe their success to the mythical and historical events that always accompanied this metal.

Can Improved Legume Varieties Optimize Iron Status in Low- and Middle-Income Countries? A Systematic Review

Iron and zinc deficiencies are some of the most widespread micronutrient deficiencies in low- and middle-income countries (LMIC). Dietary diversification, food fortification, nutrition education, and supplementation can be used to control micronutrient deficiencies. Legumes are important staple foods in most households in LMIC. Legumes are highly nutritious (good sources of essential minerals, fiber, and low glycemic index) and offer potential benefits in addressing nutrition insecurity in LMIC. Several efforts have been made to increase micronutrient intake by use of improved legumes. Improved legumes have a higher nutrient bioavailability, lower phytate, or reduced hard-to-cook (HTC) defect. We hypothesize that consumption of improved legumes leads to optimization of zinc and iron status and associated health outcomes. Therefore, the objective of this review is to examine the evidence on the efficacy of interventions using improved legumes. Nine relevant studies are included in the review. Consumption of improved legumes resulted in a ≥1.5-fold increase in iron intake. Several studies noted modest improvements in biomarkers of iron status [hemoglobin (Hb), serum ferritin (SF), and transferrin receptor] associated with consumption of improved legumes. Currently, no efficacy studies assessing the relation between consumption of improved legumes and zinc status are available in the literature. Evidence shows that, in addition to repletion of biomarkers of iron status, consumption of improved legumes is associated with both clinical and functional outcomes. The prevalence of iron deficiency (ID) decreases with consumption of improved legumes, with increases of ≤3.0 g/L in Hb concentrations. Improvement in cognition and brain function in women has been reported as well. However, further research is necessary in more at-risk groups and also to show if the reported improvements in status markers translate to improved health outcomes. Evidence from the included studies shows potential from consumption of improved legumes suggesting them to be a sustainable solution to improve iron status.

Iron, Zinc and Phytic Acid Retention of Biofortified, Low Phytic Acid, and Conventional Bean Varieties When Preparing Common Household Recipes

Biofortification is an effective method to improve the nutritional content of crops and nutritional intake. Breeding for higher micronutrient mineral content in beans is correlated with an increase in phytic acid, a main inhibitor of mineral absorption in humans. Low phytic acid (lpa) beans have a 90% lower phytic acid content compared to conventional beans. This is the first study to investigate mineral and total phytic acid retention after preparing common household recipes from conventional, biofortified and lpa beans. Mineral retention was determined for two conventional, three biofortified and two lpa bean genotypes. Treatments included soaking, boiling (boiled beans) and refrying (bean paste). The average true retention of iron after boiling was 77.2-91.3%; for zinc 41.2-84.0%; and for phytic acid 49.9-85.9%. Soaking led to a significant decrease in zinc and total phytic acid after boiling and refrying, whereas for iron no significant differences were found. lpa beans did not exhibit a consistent pattern of difference in iron and phytic acid retention compared to the other groups of beans. However, lpa beans had a significantly lower retention of zinc compared to conventional and biofortified varieties (p < 0.05). More research is needed to understand the underlying factors responsible for the differences in retention between the groups of beans, especially the low retention of zinc. Combining the lpa and biofortification traits could further improve the nutritional benefits of biofortified beans, by decreasing the phytic acid:iron and zinc ratio in beans.