The Sustainable Development Goals (SDGs) include goals for suppressing malaria and improving nutrition. The relationship between malaria and malnutrition has been extensively studied. A large number of studies have examined how malaria affects the susceptibility of individuals to malnutrition ( Bradley-Moore et al., 1985; Man et al., 1998; Mcgregor et al., 1956; Rowland et al., 1977). Malnutrition’s impact on the susceptibility of individuals to malaria has also been studied ( Bates et al., 1993; el Samani et al., 1987; Shankar, 2000), as has the impact of improving nutrition on the productivity of agricultural households ( Basta et al., 1979; Behrman et al., 1997; Brooks et al., 1979; Gilgen et al., 2001; Pitt & Rosenzweig, 1986; Popkin, 1978; Scholz et al., 1997; Strauss, 1986). However, no studies have examined how suppressing malaria could reduce the impact of malnutrition on households.

Developing more accurate estimates of how suppressing malaria would affect the welfare of malarious communities could inform decisions regarding funding for malaria elimination programs ( Willis & Hamon, 2018a). A lack of funding has been identified as the primary cause of failures to achieve or maintain elimination during the first Global Malaria Eradication Campaign (1955–1969) ( Cohen et al., 2012).

Malnutrition is a disease category that includes both undernutrition and overnutrition ( WHO, 2017). While overnutrition can lead to obesity, undernutrition is caused by deficiencies in micronutrients. The term malnutrition is often used as an alternative to undernutrition. Childhood stunting is the product of disease and undernutrition. Stunting in a child is defined as the child’s height-for-age Z score (HAZ) being less than two standard deviations below the median score of a healthy reference population.

In sub-Saharan Africa, 30% of the 155 million children under the age of five experienced stunting in 2016 ( Skoufias, 2018) and approximately 25% of the population experiences chronic undernourishment ( Ehui, 2018). These figures are causally linked as chronic malnutrition is one of the prime factors leading to stunting ( Gray et al., 2006; Schwinger et al., 2017). The rate of stunting among the under-five population in Africa was the highest in the world in 2016.

The number of children with stunted growth under the age of five is increasing in sub-Saharan Africa ( Skoufias et al., 2018), a trend not observed in any other region of the world. From 1990 to 2014, the number of stunted children under five increased by 23%, from 47 million to 58 million ( UNICEF). In contrast, the number of children with stunting decreased by 52% in Asia, 55% in Latin America (including the Caribbean) and 38% globally ( UNICEF).

One reason for this increase is the rapid rise in the child population of sub-Saharan Africa. From 2015 until the end of the century, sub-Saharan Africa will have a higher number of births than any other part of the world ( UNICEF). Another reason, however, is that Africa has made slower progress towards reducing the percentage of children with stunting than other regions of the world ( UNICEF). From 1990 to 2014, the percentage of stunted children under five in Africa decreased by only 24%, while the percentage in Asia declined by 47%, in Latin America (including the Caribbean) by 52% and globally by 40% ( UNICEF).

Interventions to reduce childhood stunting include nutrition-specific or nutrition-sensitive interventions. Nutrition-specific interventions include providing micronutrients and vitamins to mothers and promoting breastfeeding. Although the efficacy of these interventions is high, developing countries have found it challenging to scale-up these approaches in resource-constrained settings ( Galasso et al., 2016). These nutrition-sensitive interventions target the determinants of malnutrition rather than providing improved nutrition options directly to mothers. Nutrition-sensitive interventions include interventions that increase the productivity of agricultural households ( Berti et al., 2004; De Brauw et al., 2015; Girard et al., 2012; Masset et al., 2012; Ruel et al., 2013). Suppressing malaria could have a similar impact on stunting given that recent studies indicate that malaria suppression could increase productivity and reduce poverty in agricultural households ( Willis & Hamon, 2018a; Willis & Hamon, 2018b). The objective of this study is to highlight how suppressing malaria could affect stunting rates among children in agricultural households in sub-Saharan Africa.

Figure 1 was developed in a recent study ( Willis & Hamon, 2019) as a conceptual framework to illustrate how eradicating malaria could create a virtuous cycle that improves the welfare of agricultural households. In previous studies, we examined the links from “Malaria decreases” to “Household income increases” ( Willis & Hamon, 2018a; Willis & Hamon, 2018b). In the current study we examine the evidence for the links in Figure 1 from “Household income increases” (due to suppressing malaria) to “Nutrition security improves.”

The relevant Sustainable Development Goals (SDGs) for malaria and malnutrition are summarized in Table 1. The goal for stunting is to achieve a 40% reduction in stunting rates among children under five by 2025 using 2010 as a baseline ( Hawkes & Fanzo, 2017).

Based on the current global progress toward reducing stunting, this goal will not be achieved ( Hawkes & Fanzo, 2017). The number of stunted children under five globally is decreasing at a rate of 1.5% annually, which will lead to only a 20% reduction in stunting from 2010 to 2025 ( Galasso et al., 2016). In order to reach the goal of a 40% reduction by 2025, the annual reduction in stunting will need to increase from 1.5 to 3.4% ( Galasso et al., 2016).

In Table 3, we summarize the evidence for changes in poverty and stunting from a case study of Peru ( Levinson et al., 2013). The top section of Table 3 shows that from 2004 to 2011, the national poverty rate in Peru decreased by 31 percentage points, from 58.8% to 27.8% ( Skoufias et al., 2018).

The lower part of Table 3 summarizes the change in stunting rates at the national level and sub-national levels for rural districts, urban districts and districts that were targeted by the government’s CRECER program. The CRECER program (the National Nutrition Strategy for Poverty Reduction and Economic Opportunities) was a multisectoral strategy to improve nutrition that included results-based incentives for local participation ( Levinson et al., 2013). Most of the districts where the program was implemented were in rural areas. While the percentage point decrease in the rural and CRECER-targeted districts was 13.8% and 21.4%, respectively, there was only a 5.1% decrease in urban areas ( Levinson et al., 2013; World Bank, 2012). Nationally, Peru experienced a 10.4 percentage point decrease from the 2007/2008 baseline period to 2012 ( Skoufias et al., 2018).

An evaluation of the impact of the CRECER program concluded that income growth played an important role in enabling multisectoral efforts to decrease undernutrition, although the declines in stunting could not be exclusively attributed to economic growth and poverty reduction ( Skoufias et al., 2018). There is increasing interest in implementing similar multisectoral nutrition programs in sub-Saharan Africa ( Hawkes & Fanzo, 2017; Skoufias et al., 2018):

In this study, we examine a third component of the cycle ( Figure 1) of the impact of malaria on the welfare of agricultural households in sub-Saharan Africa: the impact of poverty reduction on stunting. This builds on our work showing the potential impact of eliminating malaria on the productivity and incomes of such households ( Willis & Hamon, 2018a; Willis & Hamon, 2018b; Willis & Hamon, 2019).

We have developed new estimates indicating that there were approximately 21.5 million children with stunting in agricultural households in malarious regions of sub-Saharan Africa in 2018. We further identify a link between poverty reduction and a reduction in stunting on the basis of recent evidence from a nutrition program in Peru ( Skoufias et al., 2018).

As our previous work has shown that eliminating malaria by 2040 would lead to a 6.3–37.9% decrease in poverty in agricultural households in malarious sub-Saharan Africa, we propose that malaria elimination efforts should be seen as having the additional benefit of mitigating the major health challenge of stunting. This has implications for funding for malaria elimination initiatives. As most rural populations in sub-Saharan Africa experience high rates of both malaria transmission and stunting, the international development community should not consider these two problems as isolated challenges: policies that successfully suppress one will also affect the other.

Figure 1 contains a link from ‘Nutrition security improves’ to ‘Health Improves.’ Many of the long-term physical, social and cognitive impacts of stunting are irreversible. Undernourishment not only leads to stunting but also inhibits cognitive development. Individuals who experience stunting in childhood are at higher risk of non-communicable diseases as adults and often have reduced socioemotional skills. Reducing stunting leads not only to improved health as an adult but may also increase productivity, as childhood stunting is associated with delayed schooling and lower incomes as adults ( Black et al., 2013; Galasso et al., 2016; Hoddinott et al., 2013; Victora et al., 2016).

In addition to developing a vision for eradicating malaria by 2040 ( Gates & Chambers, 2015), the Bill and Melinda Gates Foundation has recognized the importance of eliminating malnutrition. Bill Gates specifically stated in a 2018 interview (with Business Insider) that this would be his target were he to have a magic wand.

One potential limitation to our study is that the relationship between poverty rates and stunting may be distinctly different in Peru than in sub-Saharan Africa. A decrease in poverty rates among agricultural households in sub-Saharan Africa may have a larger or smaller impact on stunting rates than was observed in Peru.

Future research should examine how improvements in income, education levels and gender equality due to suppressing malaria among agricultural households in sub-Saharan Africa would affect malnutrition and stunting. To address this research question, we recommend the collection of longitudinal data from households in Africa from a range of agro-ecosystems. Collecting longitudinal data of this type would help generate knowledge regarding heterogeneities in the impact of suppressing malaria on malnutrition and stunting across communities and over time.

The dataset for this research, Malaria among agricultural households in 2018 in sub-Saharan Africa - July 2018, has been deposited in CSV format with Harvard Dataverse. DOI: https://doi.org/10.7910/DVN/ZFJ3XT ( Willis, 2018).

Data are available under the terms of the Creative Commons Zero "No rights reserved" data waiver (CC0 1.0 Public domain dedication).