Assessing the potential of household food processing to improve zinc nutrition in Malawi
Malawi is one of the least-developed countries in sub-Saharan Africa, with high rates of food insecurity, stunting, and micronutrient malnutrition. Zinc deficiency is associated with a number of health problems in Malawi, including diarrhea, pneumonia, stunting, and adverse pregnancy outcomes. Maize is the staple of the national diet, yet the zinc nutrition of maize-based diets is compromised by the presence of phytate, a potent inhibitor of zinc absorption. Phytate levels can be reduced by basic household processing methods such as soaking, germinating, and fermenting, thus increasing the rate of zinc absorption. Novel research on sustainable approaches to addressing malnutrition using these kinds of food-based methods is urgently needed. Using food consumption data from the Malawi Third Integrated Household Survey and the latest models to predict zinc absorption, this study estimates the proportion of the population at risk of zinc deficiency, with a focus on vulnerable sub-groups including women and children. Next, it uses a simulation model to estimate the effects of reducing dietary phytate through processing and compares those results to an alternative simulation based on biofortification. Finally, this study examines the practical considerations necessary to promote improved maize processing using a behavior change communication approach and estimates the cost-effectiveness of the intervention compared to alternatives. The study"'s findings indicate that the initially high proportion of people at risk of zinc deficiency in Malawi can be substantially reduced by processing maize to reduce phytate. Compared to biofortification, the impact of processing was greater for all regions and sub-groups, and the advantage of processing was more pronounced in the South and in rural areas. An intervention to promote these improved methods using behavior change communication and nutrition education compares favorably against alternatives on a cost-effectiveness basis. A thorough analysis of culture and gender norms, the decision-making context, and the drivers of food choice in Malawi suggest that an intervention to promote household-level maize processing can be culturally appropriate and scalable if the context is properly considered. Given these findings, food-based approaches such as household level food processing should be given greater attention in policy and practice to sustainably improve food security and health outcomes.