Corn Masa Flour--A Promising New Vehicle for Iron Fortification in Mexico and Central America

Iron deficiency anemia (IDA) is the most prevalent nutritional disorder worldwide. The World Health Organization estimated that IDA affects approximately 50 percent of children, 42 percent of women and 26 percent of men in developing countries. IDA impairs cognitive development, lowers work capacity, reduces resistance to disease and, in severe cases, can lead to neonatal and maternal mortality.

Alleviating IDA through the fortification of commonly consumed foods can have far-reaching health benefits. However, it has not proven easy to identify iron fortificants that work effectively (e.g., that are readily bioavailable), that will be adopted by industry, and that are opaque to consumers. Iron food fortificants pose special challenges in this respect. The compounds most readily absorbed during digestion also tend to react negatively with foods, causing taste and color changes and accelerating rancidity. While elemental iron powders pose few of these organoleptic problems, significant confusion exists about their absorption during digestion, hence value to iron-deficient populations.

SUSTAIN began to explore the potential for iron fortification of corn masa flour in Central America following technical assessments in 1996 and 1997 of iron fortification practices at wheat mills in El Salvador, Guatemala, Nicaragua and Honduras. In the course of these assessments, the SUSTAIN team also visited two plants that were manufacturing corn masa flour (CMF), a widely available and increasingly popular product used to make tortillas in Mexico and Central America, and a promising new vehicle for iron fortification. In a review of relevant scientific literature and industrial experience SUSTAIN found that only very limited information existed about CMF fortification.

SUSTAIN convened a technical advisory panel of specialists from the corn masa flour industry, scientific institutions and governments to consider issues relevant to the product's fortification. Based on their recommendations that a range of iron compounds be screened for consumer acceptability, storage performance and bioavailability, we sponsored several phases of research.

In 1998, a groundbreaking agreement was signed between industry and government representatives in Mexico to voluntarily fortify both wheat and corn masa flour with iron and other micronutrients. However, anticipated progress towards enforceable regulatory action stalled - among other issues, the choice of appropriate iron fortificant became a sticking point for all parties to the agreement. Following SUSTAIN's initial research, more was known about the characteristics of some of the more soluble iron fortificants in corn masa flour, but questions remained about their cost and consumer acceptability. Moreover much remained to be learned about the bioavailability of the elemental iron powders favored by industry.

In late 1999 and early 2000, SUSTAIN held a number of planning meetings with industry, government and public health representatives in Mexico to examine the issues that appeared to be impeding progress on fortification initiatives and standards. Participants cited confusion and conflicting data regarding the efficacy of elemental iron powders-the most commonly used iron fortificants worldwide-as a major impediment. Both industries and government representatives asked SUSTAIN to help address this situation.

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. Drawing on its findings and recommendations, SUSTAIN drafted the Guidelines for Iron Fortification of Cereal Food Staples, an interim tool to help program planners select and use optimal iron fortificants for specific public health programs.

In late 2002 and early 2003, SUSTAIN returned to Mexico for consultations with the government and industries on staple food fortification, which flour manufacturers had agreed to pursue on a voluntary basis in 1998. Specifically we assessed progress toward national fortification of corn masa flour as well as the level of industry support for mandatory fortification standards for this popular product. As a result of Mexico's recent national nutrition survey, there is broad awareness of the country's nutritional problems and a commitment from government to address these in partnership with industry. SUSTAIN continues to work with public and private sector specialists to achieve national standards for the micronutrient fortification of staple foods.