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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Plant, Soil and Nutrition Research » Research » Publications at this Location » Publication #341809

Research Project: Bioavailability of Iron, Zinc and Select Phytochemicals for Improved Health

Location: Plant, Soil and Nutrition Research

Title: Iron bioavailability studies of the first generation of iron-biofortified beans released in Rwanda

Author
item Glahn, Raymond
item Tako, Elad
item Hart, Jonathan
item Haas, Jere - Cornell University - New York
item Lung'aho, Mercy - International Center For Tropical Agriculture (CIAT)
item Beebe, Steve - International Center For Tropical Agriculture (CIAT)

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2017
Publication Date: 7/21/2017
Citation: Glahn, R.P., Tako, E., Hart, J.J., Haas, J., Lung'Aho, M., Beebe, S. 2017. Iron bioavailability studies of the first generation of iron-biofortified beans released in Rwanda. Nutrients. 9(7):787.

Interpretive Summary: Iron (Fe) deficiency is the leading nutritional deficiency worldwide. One of the primary strategies now used to combat Fe deficiency is a process known as “biofortification.” Iron biofortification involves breeding staple food crops with higher levels of Fe. Such efforts over the past 15 years resulted in the first generation of high Fe beans, released in Rwanda, which are the subject of investigation and characterization in this paper. This study presents a series of cell culture (in vitro) Fe bioavailability experiments, Fe content analysis and polyphenolic profile of the first generation of Fe biofortified beans (Phaseolus vulgaris) selected for human trials in Rwanda and released to farmers of that region. The objective of the present study was to demonstrate how the Caco-2 cell bioassay for Fe bioavailability can be utilized to assess the nutritional quality of Fe in such varieties and how they may interact with diets and meal plans of experimental studies. Furthermore, experiments were also conducted to directly compare this in vitro approach with specific human absorption studies of these Fe biofortified beans. The results show that the high Fe beans should provide more absorbable Fe, but this effect is tempered by higher levels of compounds in the bean seed coat that can inhibit Fe absorption. Results also show that other foods commonly consumed with beans, such as rice, can negatively affect Fe bioavailability whereas potato may enhance the Fe absorption when consumed with beans. The results further suggest that the extrinsic labelling approach to measuring human Fe absorption can be flawed and thus provide misleading information. The Caco-2 cell bioassay represents an effective approach to evaluate the nutritional quality of Fe-biofortified beans, both separate from and within a targeted diet or meal plan.

Technical Abstract: This paper represents a series of in vitro Fe bioavailability experiments, Fe content analysis and polyphenolic profile of the first generation of Fe biofortified beans (Phaseolus vulgaris) selected for human trials in Rwanda and released to farmers of that region. The objective of the present study was to demonstrate how the Caco-2 cell bioassay for Fe bioavailability can be utilized to assess the nutritional quality of Fe in such varieties and how they may interact with diets and meal plans of experimental studies. Experiments were also conducted to directly compare this in vitro approach with specific human absorption studies of these Fe biofortified beans. The results show that other foods consumed with beans, such as rice, can negatively affect Fe bioavailability whereas potato may enhance the Fe absorption when consumed with beans. Replication of the meals used in a human study where bean meals were extrinsically labelled with 58Fe indicate that the extrinsic labelling approach to measuring human Fe absorption can be flawed and thus provide misleading information. Overall, this work demonstrates application of the Caco-2 cell bioassay as an effective approach to evaluate the nutritional quality of Fe-biofortified beans, both separate from and or within a targeted diet or meal plan.