A review of phytate, iron, zinc, and calcium concentrations in plant-based complementary foods used in low-income countries and implications for bioavailability

Department of Human Nutrition, University of Otago, Union Street, PO Box 56, Dunedin 9015, New Zealand.
Food and nutrition bulletin (Impact Factor: 1.15). 06/2010; 31(2 Suppl):S134-46.
Source: PubMed


Plant-based complementary foods often contain high levels of phytate, a potent inhibitor of iron, zinc, and calcium absorption. This review summarizes the concentrations of phytate (as hexa- and penta-inositol phosphate), iron, zinc, and calcium and the corresponding phytate:mineral molar ratios in 26 indigenous and 27 commercially processed plant-based complementary foods sold in low-income countries. Phytate concentrations were highest in complementary foods based on unrefined cereals and legumes (approximately 600 mg/100 g dry weight), followed by refined cereals (approximately 100 mg/100 g dry weight) and then starchy roots and tubers (< 20 mg/100 g dry weight); mineral concentrations followed the same trend. Sixty-two percent (16/26) of the indigenous and 37% (10/27) of the processed complementary foods had at least two phytate:mineral molar ratios (used to estimate relative mineral bioavailability) that exceeded suggested desirable levels for mineral absorption (i.e., phytate:iron < 1, phytate:zinc < 18, phytate:calcium < 0.17). Desirable molar ratios for phytate:iron, phytate:zinc, and phytate:calcium were achieved for 25%, 70%, and 57%, respectively, of the complementary foods presented, often through enrichment with animal-source foods and/or fortification with minerals. Dephytinization, either in the household or commercially, can potentially enhance mineral absorption in high-phytate complementary foods, although probably not enough to overcome the shortfalls in iron, zinc, and calcium content of plant-based complementary foods used in low-income countries. Instead, to ensure the World Health Organization estimated needs for these minerals from plant-based complementary foods for breastfed infants are met, dephytinization must be combined with enrichment with animal-source foods and/or fortification with appropriate levels and forms of mineral fortificants.

Download full-text


Available from: Michelle Gibbs, May 24, 2015
73 Reads
  • Source
    • "The total contents of Fe, Zn, Ca and Mg in a given food product are not the only criteria determining its nutritional quality, as it also depends on their bioavailability from that product. In order to determine whether a product is a good source of a particular mineral, it is necessary to determine the amount of that mineral released or absorbed in the animal or human organism (Gibson et al. 2010). There are various in vitro and in vivo methods to determine bioaccessibility of minerals (Skibniewska et al. 2002). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The objective of this study was to determine the content and the bioaccessibility of minerals (Fe, Zn, Ca and Mg) in commonly consumed food products, such as cereal groats, rice, leguminous grains and nuts purchased from the local market. The contents of Fe, Zn, Ca and Mg in foods were assayed after dry ashing of samples, while the bioaccessibility of these minerals after enzymatic in vitro digestion, was determined by flame atomic absorption spectrometry. A relatively high content of Fe was found in cashew nuts and green lentils, while cashew nuts and buckwheat groats had the highest concentration of Zn. It was found that the highest amount of macro-elements was generally in nuts, in particular: brazil nuts (Ca and Mg), cashews (Mg) and hazelnuts (Ca and Mg). Concerning the mineral bioaccessibility, the highest values for Fe were obtained in cashew nuts and green lentils (2.8 and 1.7 mg/100 g), for Zn in green lentils (2.1 mg/100 g), for Ca in brazil nuts and shelled pea (32.6 and 29.1 mg/100 g), while for Mg in shelled peas and green lentils (43.4 and 33.9 mg/100 g). Generally, the best sources of bioaccessible minerals seem to be leguminous grains and nuts.
    Journal of Food Science and Technology -Mysore- 03/2014; 51(3). DOI:10.1007/s13197-011-0535-5 · 2.20 Impact Factor
  • Source
    • "This illustrates that transitioning directly to “family foods” as the sole source of complementary foods may put the infant at risk of multiple micronutrient deficiencies. Even when “improved” complementary food recipes are developed, they usually fall short of providing adequate iron, zinc, and sometimes calcium (11). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Breast-fed infants and young children need complementary foods with a very high nutrient density (particularly for iron and zinc), especially at ages 6-12 mo. However, in low-income countries, their diet is usually dominated by cereal-based porridges with low nutrient density and poor mineral bioavailability. Complementary feeding diets typically fall short in iron and zinc and sometimes in other nutrients. These gaps in nutritional adequacy of infant diets have likely been a characteristic of human diets since the agricultural revolution ∼10,000 y ago. Estimates of nutrient intakes before then, based on hypothetical diets of preagricultural humans, suggest that infants had much higher intakes of key nutrients than is true today and would have been able to meet their nutrient needs from the combination of breast milk and premasticated foods provided by their mothers. Strategies for achieving adequate nutrition for infants and young children in modern times must address the challenge of meeting nutrient needs from largely cereal-based diets.
    Journal of Nutrition 10/2013; 143(12). DOI:10.3945/jn.113.182527 · 3.88 Impact Factor
  • Source
    • "Poor quality foods is the first category of determinants negatively impacting infant and young child growth. Inadequacies in micronutrient nutrition may arise from low dietary diversity (Onyango et al. 1998; Arimond & Ruel 2004), limited or no intake of animal source foods (Marquis et al. 1997; Bwibo & Neumann 2003; Krebs 2007), and high anti-nutrient content such as phytates and polyphenols in the plant-based diets of many poor populations (Gibson et al. 2010; Roos et al. 2013). The second category is inadequate practices. "
    [Show abstract] [Hide abstract]
    ABSTRACT: An estimated 165 million children are stunted due to the combined effects of poor nutrition, repeated infection and inadequate psychosocial stimulation. The complementary feeding period, generally corresponding to age 6–24 months, represents an important period of sensitivity to stunting with lifelong, possibly irrevocable consequences. Interventions to improve complementary feeding practices or the nutritional quality of complementary foods must take into consideration the contextual as well as proximal determinants of stunting. This review presents a conceptual framework that highlights the role of complementary feeding within the layers of contextual and causal factors that lead to stunted growth and development and the resulting short- and long-term consequences. Contextual factors are organized into the following groups: political economy; health and health care systems; education; society and culture; agriculture and food systems; and water, sanitation and environment. We argue that these community and societal conditions underlie infant and young child feeding practices, which are a central pillar to healthy growth and development, and can serve to either impede or enable progress. Effectiveness studies with a strong process evaluation component are needed to identify transdisciplinary solutions. Programme and policy interventions aimed at preventing stunting should be informed by careful assessment of these factors at all levels.
    Maternal and Child Nutrition 09/2013; 9(S2). DOI:10.1111/mcn.12088 · 3.06 Impact Factor
Show more