Objective: To study heme iron bioavailability and the role of dietary protein (animal and vegetable) on iron uptake using an in vitro model (Caco-2 cell line).
Methods: Caco-2 cells were seeded in bicameral chambers with different animal (beef, chicken or fish) or vegetable (peas, lentils, and soybeans) proteins or with pure animal (collagen and casein) or vegetable (gliadin, zein, and glutein) protein extracts. The effect of each protein over heme iron absorption was assessed.
Results: Intact heme uptake was higher than either heme plus albumin or digested heme plus albumin, but lower than digested heme. White meal exerted the highest inhibitory effect on hemin uptake. Heme iron uptake decreased in the presence of all legume extracts, but was not significantly different among them (one-way ANOVA, NS). Pure animal (collagen and casein) and vegetable (zein and glutelin) proteins increased heme iron uptake, except for gliadin.
Conclusion: Animal and vegetable protein in general decreased heme iron uptake. However, purified animal and vegetable protein induce an increase in heme iron uptake.