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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 #317595
Title: Iron absorption from intrinsically-labeled lentils

Author
item DELLA VALLE, DIANE - Former ARS Employee
item Glahn, Raymond
item SHAFF, JON - Cornell University
item O'BRIEN, KIMBERLY - Cornell University

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/3/2015
Publication Date: 9/2/2015
Citation: Della Valle, D.M., Glahn, R.P., Shaff, J., O'Brien, K.O. 2015. Iron absorption from intrinsically-labeled lentils. Journal of Nutrition. DOI: 10.3945/jn.115.217273.

Interpretive Summary: Low iron (Fe) absorption from important staple foods may contribute to Fe deficiency in developing countries. To date, there are few studies examining the Fe bioavailability (ie. absorbability) of pulse crops as commonly prepared and consumed by humans. The objectives of this study were to characterize the Fe absorption from a test meal of lentils that were grown in a greenhouse setting which enabled “isotopic” measurement of Fe absorption. We measured Fe absorption from the lentils, and compared it to absorption from a standard form of Fe in order to get an accurate picture of the relative Fe absorption from lentils. This study included 19 healthy non-pregnant women. We found that Fe absorption from the lentil meal averaged 2.24 +/- 3.44% and was significantly lower than the 23.56 +/- 13.22% observed from the reference standard Fe. As expected, iron deficient women absorbed significantly more Fe of either source compared to those who were of adequate Fe status. In conclusion, Fe absorption from the lentil meal was low overall, but was upregulated in women with poor Fe status. This research establishes a better baseline picture of what can be expected of Fe absorption from lentils, and thus is valuable information to lentil breeding and development for improved Fe nutrition.

Technical Abstract: Low iron (Fe) absorption from important staple foods may contribute to Fe deficiency in developing countries. To date, there are few studies examining the Fe bioavailability of pulse crops as commonly prepared and consumed by humans. The objectives of this study were to characterize the Fe absorption from a test meal of intrinsically-labeled Fe lentils; to compare the bioavailability of Fe from Fe-intrinsically-labeled lentils to that observed for a reference dose of Fe as ferrous sulfate (FeSO4); and to assess associations between Fe absorption and Fe status indicators. This study included 19 healthy non-pregnant women. All women ingested both ferrous sulfate (7 mg FeSO4 plus 1 mg Fe and 117 g of intrinsically-labeled raw lentils (enriched to 85.05% with Fe) prepared as dal and containing a total of 8 mg native Fe. Iron absorption was determined by analyzing blood samples taken 14 d post-dosing with the use of magnetic sector thermal ionization mass spectrometry. We found that Fe absorption from the lentil meal averaged 2.24 +/- 3.44% and was significantly lower than the 23.56 +/- 13.22% observed from the same Fe load given as FeSO4 (p<0.001). Absorption of non-heme Fe from lentils and from FeSO4 was significantly associated with serum ferritin (SF; p=0.05 and p<0.001, respectively) and serum hepcidin (p=0.05 and p=0.007, respectively). Anemic women absorbed significantly more Fe of either source compared to those who were Fe replete (p=0.001). In conclusion, Fe absorption from the lentil meal was low overall, but was upregulated in women with poor Fe status. Both SF and hepcidin were inversely associated with Fe absorption from both a supplemental and a food-based non-heme Fe source in non-anemic and anemic women, and explained ~20% of the variance in Fe absorption from the lentil meal.