TY - JOUR
T1 - Iron retention by rats from casein-legume test meals
T2 - Effect of tannin level and previous diet
AU - Garcia-Lopez, J. S.
AU - Erdman, J. W.
AU - Sherman, A. R.
PY - 1990
Y1 - 1990
N2 - The effect of tannin content on iron (Fe) bioavailability from several legumes was evaluated. Absorption of Fe from a casein (C), isolated soy protein (ISP), chickpea (CP) or red kidney bean (RKB) test meal was tested in marginally Fe-deficient rats [9.9 ± 0.2 g Hb/100 mL (mean ± SD)] using the extrinsic tag technique. Also, the effects of a casein habitual diet or of one of three casein-legume habitural diets fed before and after the test meal were investigated. Weanling male rats were fed the habitual diets containing 23 ± 4 mg Fe/kg of diet (range 17-28) for 13 d. On d 14, after an overnight fast, rats were fed the test meal (1.5g + 0.1μCi 59Fe), and whole-body radioactivity was determined. The same habitual diet was refed for seven additional days, and whole-body radioactivity was determined again. Rats retained more iron from C (86%) than from ISP, CP or RKB test meals (73%, 75% and 67%, respectively) when the respective casein-legume habitual diets were fed before and after the test meals. With the casein habitual diet, there was no difference in retained iron from C, ISP, CP or RKB test meals (86%, 87%, 83% and 82%, respectively). Retention of iron from an RKB test meal was increased from 69.6 to 73% when about 90% of the extractable tannins were removed, but the difference was not statistically significant. Thus, feeding a casein-legume diet but not a casein diet prior to a test meal apparently predisposes the rat to lower iron absorption. However, in these studies, tannins per se did not significantly depress iron bioavailability.
AB - The effect of tannin content on iron (Fe) bioavailability from several legumes was evaluated. Absorption of Fe from a casein (C), isolated soy protein (ISP), chickpea (CP) or red kidney bean (RKB) test meal was tested in marginally Fe-deficient rats [9.9 ± 0.2 g Hb/100 mL (mean ± SD)] using the extrinsic tag technique. Also, the effects of a casein habitual diet or of one of three casein-legume habitural diets fed before and after the test meal were investigated. Weanling male rats were fed the habitual diets containing 23 ± 4 mg Fe/kg of diet (range 17-28) for 13 d. On d 14, after an overnight fast, rats were fed the test meal (1.5g + 0.1μCi 59Fe), and whole-body radioactivity was determined. The same habitual diet was refed for seven additional days, and whole-body radioactivity was determined again. Rats retained more iron from C (86%) than from ISP, CP or RKB test meals (73%, 75% and 67%, respectively) when the respective casein-legume habitual diets were fed before and after the test meals. With the casein habitual diet, there was no difference in retained iron from C, ISP, CP or RKB test meals (86%, 87%, 83% and 82%, respectively). Retention of iron from an RKB test meal was increased from 69.6 to 73% when about 90% of the extractable tannins were removed, but the difference was not statistically significant. Thus, feeding a casein-legume diet but not a casein diet prior to a test meal apparently predisposes the rat to lower iron absorption. However, in these studies, tannins per se did not significantly depress iron bioavailability.
KW - Bioavailability
KW - Iron
KW - Legumes
KW - Rats
KW - Tannin
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U2 - 10.1093/jn/120.7.760
DO - 10.1093/jn/120.7.760
M3 - Article
C2 - 2366110
AN - SCOPUS:0025281377
SN - 0022-3166
VL - 120
SP - 760
EP - 766
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 7
ER -