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 (58)Fe and a reference dose of 6 mg (57)Fe; 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.