Iron absorption in raw and cooked bananas: a field study using stable isotopes in women

Background: Banana is a staple food in many regions with high iron deficiency and may be a potential vehicle for iron fortification. However, iron absorption from bananas is not known. Objective: The objective of this study was to evaluate total iron absorption from raw and cooked bananas. Design: Thirty women (34.9 +/- 6.6 years) from rural Mexico were randomly assigned to one of two groups each consuming: 1) 480 g/day of raw banana for 6 days, or 2) 500 g/day of cooked banana for 4 days. Iron absorption was measured after extrinsically labeling with 2 mg of Fe-58 and a reference dose of 6 mg Fe-57; analysis was done using ICP-MS. Results: Iron content in cooked bananas was significantly higher than raw bananas (0.53 mg/100 g bananas vs. 0.33 mg/100 mg bananas, respectively) (p < 0.001). Percent iron absorption was significantly higher in raw bananas (49.3 +/- 21.3%) compared with cooked banana (33.9 +/- 16.2%) (p = 0.035). Total amount of iron absorbed from raw and cooked bananas was similar (0.77 +/- 0.33 mg vs. 0.86 +/- 0.41 mg, respectively). Conclusion: Total amount of absorbed iron is similar between cooked and raw bananas. The banana matrix does not affect iron absorption and is therefore a potential effective target for genetic modification for iron biofortification.