Emerging Approaches to Addressing Iron Insufficiency

Even in the 21st century, iron deficiency remains a global public health challenge. According to the World Health Organization, iron deficiency is the most common and widespread nutritional disorder in the world. Statistics indicate that 2 billion people—over 30% of the population—are anemic, many due to iron deficiency (WHO, 2013).

Iron deficiency contributes to multiple co-morbidities including chronic heart failure (Klip et al., 2013), inflammatory disease (Parikh et al., 2011), and possibly psychiatric disorders among children and adolescents (Chen et al., 2013). On the flip side of these iron-deficiency associated conditions, iron overload or hemochromatosis contributes to an array of adverse health outcomes including disorders that affect the heart, liver, pancreas, and other organs as well as joints. Recent studies suggest HFE hemochromatosis is an autosomal recessive disorder common among European whites (Barton, 2013).

Many food scientists and nutritionists, based on their understanding of iron compatibility issues in food matrices and processing environments, and their comprehension of iron absorption and metabolism, have leveraged a variety of non-heme salts and chelates, non-heme ferritin (e.g., legumes), phytase-treated beans, and heme iron (meats) in efforts to assure an adequate iron status among consumers. Each of these sources is unique in its stability in foods, and its bioavailability and absorption mechanism among humans. To achieve and maintain iron homeostasis, a clear understanding of iron absorption is critical. An important component of that understanding is genetic variables. This includes the impact of a myriad of cell receptors and transporter proteins that require extensive biological coordination, which ultimately influence iron nutritional status (Theil, 2011).

Epidemiological evidence indicates those inclined to follow vegetarian dietary patterns are less likely to succumb to cardiovascular disease, non-cardiovascular non-cancer conditions, renal dysfunctions, and endocrine-associated health issues (Orlich et al., 2013). At the same time, vegetarian and vegan diets typically present nutrient insufficiencies, including iron deficiency anemia, particularly among pregnant and lactating women (Penney and Miller, 2008) and growing children (Craig, 2010).

Several studies suggest consuming ferritin-rich foods may be critical in the reduction of iron-deficiency anemia (Murray-Kolb et al., 2003; Sayers et al., 1973). More recently, a study among 73 healthy, non-pregnant women in Chile, demonstrated unique absorption mechanisms of ferritin iron from legumes (Theil et al., 2012).

Ferritin is a vital protein expressed in animals, plants, and many multicellular organisms, including some bacteria (Theil, 2004; Theil et al., 2013). Unlike the well-known iron chelate, ferricphytate, which has a poor biological availability, ferritin presents a unique polypeptide, tetra α-helix cage-like structure that is effectively absorbed (>20%) and utilized as well as ferrous sulfate (Murray-Kolb et al., 2003; Davila-Hicks et al., 2004; Theil and Turano, 2013).

A recent systematic assessment of iron distribution in plants, from roots to leaves, indicated low amounts of iron accumulate in vascular tissue of the root, whereas iron-ferritin complexes seem to dominate in leaves, at least in the Abrabiopsis thaliana model system (Roschzttardtz et al., 2013). This valuable information suggests that selective utilization of plant components and a better biological understanding of those components may contribute to improved food products designed to address public health issues such as iron deficiency anemia.

Among cucumber roots and pea seeds, mitochondrial ferritin is a functional iron-storage protein. This protein is important for cellular respiration, possibly protects the plant from toxic forms of the mineral, and is required for seed formation and germination (Vigani et al., 2013; Vigani et al., 2009; Lv et al., 2013; Zhang et al., 2013).

Considering global staple foods in the tropics, such as bananas, and leveraging the emerging understanding of plant genetics of this fruit and soybeans, recent research suggests it is possible to up-regulate the expression of ferritin and promote the accumulation of zinc (Kumar et al., 2011). Similar approaches to plant breeding indicate even the bio-availability of iron in corn may be markedly improved (Tako et al., 2013).

The identification of native compounds like ferritin and development of more nutrient-dense crops (biofortification) represent two approaches to increase micro-nutrient concentrations of staple foods, thereby potentially reducing the risk of nutrient insufficiencies, including iron (Mayer et al., 2008). Applying these approaches to high-yield staple crops such as rice, wheat, maize, cassava, and others and urging farmers to adopt them will require additional agricultural research and communication among consumers. If such approaches are taken, however, they can provide cost-effective interventions to combat iron-deficiency anemia (Bouis et al., 2011).

Roger Clemens