GeoNutrition - tackling hidden hunger in Sub-Saharan Africa

Lead Research Organisation: Rothamsted Research
Department Name: Sustainable Agriculture Sciences-H

Abstract

Mineral Micronutrient Deficiencies (MNDs) are widespread in sub-Saharan Africa (SSA). MNDs (a.k.a. hidden hunger) have a major detrimental effect on human health which constrains economic growth and efforts to alleviate poverty. Alleviating MNDs is a major component of the second Sustainable Development Goal (SDG2), to "End hunger, achieve food security and improved nutrition and promote sustainable agriculture", by 2030. This Foundation Award will focus on supporting efforts to reduce MNDs in Ethiopia and Malawi, two countries with widespread mineral nutrient malnutrition problems where dietary mineral intakes fall well below levels required for optimal nutrition. For example, zinc deficiency risks are >40% in both countries which causes high rates of child mortality and stunting. Selenium deficiency risks exceed 75% in Malawi, compromising the healthy functioning of human immune systems. Iron and iodine deficiencies are widespread and are the focus of widespread supplementation and food fortification programmes (i.e. technical 'fixes') in the region.

The scientific aim of this Foundation Award is to understand how the spectral properties of tropical African soils relate to plant-availability of minerals in soils and, subsequently, to the transfer of minerals into the edible portions of staple crops and diets, and to population-level biomarkers of optimal mineral status. Achieving this aim will enable the geospatial prediction of plant-available nutrients in soils and in edible crop tissues, and thereby in downstream food systems. Spectral properties have previously been measured on a massive scale by the Africa Soils Information Service (AfSIS) programme, using X-Ray Fluorescence (XRF) and Mid Infra-Red (MIR) spectroscopy. We have previously identified strong links between soil-crop-biomarkers in small-scale cross-sectional studies in Malawi.

This aim will be realised through activities in three Themes. In Theme 1, a designed soil and crop sampling programme will be conducted at 500 sites in Ethiopia. Two sets of statistical models will be developed, the first will focus on predicting relationships between total (XRF) and plant-available soil mineral concentrations, using covariate data from MIR, remote sensing and legacy data (e.g. maps) sources. The second set of models will focus on relationships between plant-available soil mineral concentrations and their concentrations in crop edible portions. In Theme 2, these data will be integrated with data from published/government sources to predict dietary mineral supply (and highlight knowledge gaps). These predictions will be tested against mineral biomarker data (e.g. blood, urine) and proxies of micronutrient status (e.g. stunting) from national surveillance programmes. Outputs of Themes 1 and 2 will be delivered in the forms of maps and reports suited to communicating with policy-makers, to include the communication of uncertainty. Maps will be used to highlight those geographical areas that are at highest likely risk of MNDs. The focus of Theme 3 is interactions with policy-makers to optimise communication strategies, and to strengthen networks and capacity to conduct longer-term R&D to address knowledge gaps in the region.

We have well-established networks of partners in Ethiopia and Malawi, including academics, high-level policy-makers, NGOs and industry, who will all play active roles to ensure that the Foundation Award delivers genuine impact that will be assessed using robust evaluation procedures.

Technical Summary

GeoNutrition is a framework to help reduce mineral Micronutrient Deficiencies (MNDs) in sub-Saharan Africa (SSA). It adds value to the Africa Soils Information Service (AfSIS) programme, whose current focus is soils information, by integrating the spheres of agriculture, nutrition and public health. The initial scope is Ethiopia and Malawi, due to established interactions with academics and policy-makers.

Our scientific aim is to understand how the spectral properties of tropical soils relate to plant-availability of soil minerals and subsequent mineral transfers into the edible portions of staple crops. Spectral properties have previously been measured by AfSIS using X-Ray Fluorescence (XRF) and Mid Infra-Red (MIR) spectroscopy.

Soils/staple-crops will be sampled at 500 new sites (Ethiopia, late-2017). Soil properties influencing plant-availability (e.g. iron sesquioxides, effective cation exchange capacity, phosphate binding capacity) and MIR/XRF (e.g. pH, organic C) analyses will be conducted on the same samples. Mechanisms controlling nutrient binding/release will be identified and plant-available soil concentrations predicted at all AfSIS sites using Linear Mixed Modelling (covariates include satellite data and legacy maps). Similar models of staple-crop mineral composition and dietary mineral supplies will be developed at co-located sites and published/government sources.

Co-regionalised mapping will include estimates of (un)certainty in visual and verbal forms. Maps will show areas to be at the highest likely risk of MNDs to frame knowledge gaps. These predictions will be tested against mineral biomarker data (e.g. blood, urine) and proxies of MND status (e.g. stunting) from national surveillance programmes. Interactions with policy-makers to optimise communication strategies for different groups, and to strengthen networks/capacity to conduct longer-term R&D to address regional knowledge gaps is embedded within the work programme.

Planned Impact

The impact of our research is aimed towards enhancing the quality of life, health and well-being of people in sub-Saharan Africa (SSA). The initial focus of GeoNutrition is Ethiopia and Malawi (Low Income Countries, LICs), both with major Micronutrient Deficiency (MND) problems, but it is scalable to other countries. By developing a multidisciplinary and geospatial 'Agriculture-to-Nutrition' framework, GeoNutrition can support several of the UN Sustainable Development Goals (SDGs), including the elimination of hunger (SDG2), good health and wellbeing (SDG3), reduced inequalities (SDG10), and responsible consumption and production (SDG12).

Preliminary and single-mineral micronutrient studies have already enabled us to link soil type to food composition, dietary mineral supply and socioeconomic factors in Malawi. This led directly to secondary biomarker analyses in the 2015/16 National Micronutrient Survey, by the Government of Malawi, which was a pilot 'Pathways to Impact' activity. Such activities will be extended in this Foundation Award, albeit on a larger scale and in multiple countries, for several mineral micronutrients. The GeoNutrition approach has potential applications across the entire African continent. The Africa Soils Information Service (AfSIS) has prepared digital soil maps across Africa.

The idea of testing the wider application of spectral properties of tropical African soils in food, nutrition and health domains is highly innovative. We have identified scientific and logistical risk factors to achieving project success in the Management Plan. However, even with partial success, this project would help to address the historical problem that expensive wet chemistry techniques are difficult to deploy in SSA. Some successes are virtually certain based on preliminary pilot-scale work.

A successful GeoNutrition project will integrate natural and social sciences approaches, and thereby provide considerable value for monitoring/testing policy interventions through a geospatial framework. This integrated, multidisciplinary, geospatial framework is designed to build an R&D platform to support evidence based policy making. For example, GeoNutrition can be used to identify areas of high/low/uncertain mineral intakes, and potential cohorts of volunteers to study the health effects of interventions for long-term monitoring.

From a natural sciences perspective, the data and approaches used in GeoNutrition have the potential to shape/enhance soil and crop management decisions, and investment in breeding programmes. For example, it can inform decisions on how to prioritise R&D and deploy new traits/varieties most effectively to benefit consumers, farmers, and the wider industry.

From a social sciences perspective, food systems research from both consumer (demand-driven) and producer (supply-driven) perspectives could potentially be transformed by being able to account for spatial variations in food mineral compositions. The flows of some minerals (e.g. zinc, iron, iodine) through food systems can be integrated into health burden/outcome-based socioeconomic frameworks (e.g. using Disability Adjusted Life Years, DALYs). Thus, our findings can contribute immediately towards influencing public policies to address MNDs at local, regional and national scales, e.g. through education and dietary diversification. We expect that our work will support the development of similar frameworks for other minerals (e.g. selenium).

Our "Pathways to Impact" activities will align directly with an ongoing (University of Nottingham-led) capacity strengthening project, funded by the Royal Society-DFID. This programme is seeking to increase doctoral training opportunities in SSA, with a focus on human (student, academic, technical) and infrastructural (lab., admin., finance) capacity. The impact of this project and wider programme is being evaluated using a Theory of Change framework, which we will also deploy for GeoNutrition.

Publications

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Jones GD (2017) Selenium deficiency risk predicted to increase under future climate change. in Proceedings of the National Academy of Sciences of the United States of America