Iron Bioavailability from Multiple Biofortified Foods Using an In Vitro Digestion, Caco-2 Assay for Optimizing a Cyclical Menu for a Randomized Efficacy Trial.

Bryan M Gannon,Raymond P Glahn,Saurabh Mehta

doi:10.1093/cdn/nzab111

Bryan M Gannon, Raymond P Glahn + Show 1 more

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https://doi.org/10.1093/cdn/nzab111

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Abstract

ABSTRACTBackgroundInadequate nutritional status contributes to substantial losses in human health and productivity globally. A multiple biofortified food crop trial targeting iron, zinc, and vitamin A deficiencies among young children and their breastfeeding mothers is being conducted in India.ObjectiveWe sought to determine the relative iron bioavailability from biofortified and conventional crops and crop combinations representative of a cyclical menu using crops targeted for inclusion in the feeding trial.MethodsCrops were procured from India, cooked, freeze-dried, and analyzed with an established in vitro digestion/Caco-2 iron bioavailability assay using a fixed sample weight. Crop proportions representative of meals planned for the human study were determined and combined such that samples included either all biofortified or all control crops. Crops were analyzed as single crops (n = 4) or crop combinations (n = 7) by variety (biofortified or control) in triplicate. The primary outcome was iron uptake measured by Caco-2 ferritin production normalized to total Caco-2 protein (nanograms of ferritin/milligrams of cell protein) analyzed for effects of crop variety and crop proportion using generalized linear models.ResultsBiofortified pearl millet alone demonstrated higher iron uptake than conventional varieties (5.01 ± 1.66 vs. 2.17 ± 0.96; P = 0.036). Addition of sweet potato or sweet potato + pulse improved iron uptake for all proportions tested in control varieties and select proportions for biofortified varieties (P ≤ 0.05). Two multiple crop combinations demonstrated modestly higher iron uptake from biofortified crops.ConclusionsOptimizing total iron delivery should consider matrix effects, processing, and promoters/inhibitors of iron absorption in addition to total iron concentration. Future directions include evaluating recipes as prepared for consumption and comparison against human iron bioavailability studies.

Highlights

Inadequate nutritional status, including low intake of iron, zinc, and vitamin A, contributes to substantial health loss globally [1,2,3]
The greatest withincrop iron differentials were with pearl millet (38.5 μg/g) and pulses (46.0 μg/g), approximately double the iron concentration between biofortified and control varieties
Zinc concentrations were higher in biofortified crop varieties, except for sweet potato

Summary

Introduction

Inadequate nutritional status, including low intake of iron, zinc, and vitamin A, contributes to substantial health loss globally [1,2,3]. Primary micronutrient targets include iron, zinc, and provitamin A due to the high burden of their deficiencies worldwide and their contributions to human health. A multiple biofortified food crop trial targeting iron, zinc, and vitamin A deficiencies among young children and their breastfeeding mothers is being conducted in India. Crop proportions representative of meals planned for the human study were determined and combined such that samples included either all biofortified or all control crops. The primary outcome was iron uptake measured by Caco-2 ferritin production normalized to total Caco-2 protein (nanograms of ferritin/milligrams of cell protein) analyzed for effects of crop variety and crop proportion using generalized linear models.

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