A New Opportunity

Sometimes a promising new approach to a persistent problem hinges on being in the right place at the right time. So it was with SUSTAIN in the mid-1990s. In collaboration with regional public sector partners and local industries, SUSTAIN sent a team of specialists to Central America to assess food fortification practices at several regional wheat mills. Of particular interest to regional health and nutrition experts was the fortification of food staples with iron. High rates of anemia in Mexico and Central America have been attributed in large part to cereal-based diets that are low in bioavailable iron and rich in iron absorption inhibitors such as phytic acid and polyphenols.

The burden of iron deficiency anemia (IDA) falls most heavily on women and children. IDA impairs cognitive development, lowers work capacity, reduces resistance to disease and, if severe, can lead to neonatal and maternal death. IDA and its adverse health effects can potentially be reduced by fortifying food staples with iron.

During its assessment of wheat fortification practices in the region SUSTAIN learned of a relatively new maize-based flour that was becoming increasingly popular in both Central America and Mexico. The central importance of maize in regional diets (in Mexico, consumption of maize is five times that of wheat), and the recently introduced commercial production of corn masa flour (CMF) suggested to SUSTAIN a new fortification opportunity for iron deficient populations. Consequently the assessment team adjusted its schedule to visit two "corn masa" plants.

The more SUSTAIN learned, the more promising corn masa flour seemed as a new fortificant vehicle. The product -- a time-saving alternative to tortilla production from raw ingredients -- had already entered mainstream markets and its market share, especially in urban and urbanizing areas had been steadily increasing. CMF mixes readily with other dry ingredients.

The Challenge

Despite the potential widespread public health benefits of fortifying corn masa flour, little was known about how to go about it. In a review of scientific literature, SUSTAIN found nothing published on iron fortification of corn masa flour and industrial experience with the practice was limited. Moreover, potential complications existed.

The success of iron fortification depends on a number of inter-related factors, including the fortificant compound, the food vehicle, the diet consumed in combination with that vehicle, and the iron status of the consumer. The central challenge for any strategy to fortify CMF is to select an iron additive that is highly absorbable, (bioavailable), affordable, and opaque to consumers. Unfortunately, the more soluble forms of iron tend to be more chemically reactive with foods, resulting in undesirable changes in taste and color. Iron is also a catalyst for lipid oxidation and peroxidation in cereals during storage and consequently can reduce shelf life. Some forms of iron also react strongly with sulfur compounds; corn is high in sulfur-containing amino acids. Thus, the selection of the iron fortificant for CMF is critical and complex.

To begin to deal with these issues, and to foster successful CMF fortification initiatives in the region, SUSTAIN convened a technical advisory panel of specialists from the corn masa flour industry, scientific institutions and government. Based on their recommendations, SUSTAIN initiated several phases of research to evaluate a range of iron compounds for consumer acceptability, storage performance and bioavailability.

Working with Public and Private Sectors Toward Fortification Standards

In 1998, a groundbreaking agreement was signed between industry and government representatives in Mexico to fortify both wheat and corn masa flour with iron and other micronutrients. The agreement -- the first attempt to establish standards for the fortification of CMF -- is widely regarded to be a model for the region. However, progress toward implementation faltered, in part, due to technical concerns such as the the selection and use of iron fortificants.

In late 1999 and early 2000, SUSTAIN met with partner organizations and with industry and government representatives in Mexico and Central America to examine issues that appeared to be slowing the adoption of fortification standards. While more had been learned about the performance of iron compound fortificants, questions remained about the efficacy of elemental iron powders--the most widely used iron fortificants worldwide. Iron powders are relatively inexpensive and non-reactive with food vehicles (hence industry's preference for using them as food fortificants). However, previously published data on their relative bioavailabilities were confusing and often in conflict. Could one or more of these powders be effective in improving the iron status of iron-deficient populations? Both industry and government representatives asked SUSTAIN to help address this critical question. Without a better understanding of how the various powders performed, consensus on appropriate fortificant choices and standards would be elusive.

In response, SUSTAIN convened a panel of world-renowned research scientists, physicians and industry specialists to review nearly 45 years of research on elemental iron powders, and to discuss how to interpret conflicting bioavailability data. The Monterrey (Mexico) Workshop proved to be a highly effective step toward clarification.