Petry N, Egli I, Campion B, Nielsen E, and Hurrell R.
July 2013 – Journal of Nutrition
Iron bioavailability from common beans is negatively influenced by phytic acid and polyphenols. Newly developed low-PA (lpa) beans with 90% less PA and variable PPs might improve iron bioavailability. The aim of this study was to evaluate the influence of lpa beans on iron bioavailability in women (n = 20). We compared iron absorption from 4 different beans using a paired, double meal, crossover design. Iron absorption was measured as erythrocyte incorporation of stable iron isotopes from 2 lpa bean lines, one high in PPs and one low in PPs. The other 2 beans used were their parents with a normal PA concentration, one high in PPs and one low in PPs. Fractional iron absorption from the lpa bean high in PPs was 6.1%, which was 60 and 130% higher compared with the parent high in PPs (P < 0.001) and low in PPs (P < 0.001), respectively. The total amount of iron absorbed per test meal from the lpa bean high in PPs (372 μg) was 60 and 163% higher compared with the parent high in PPs (P < 0.001) and low in PPs (P < 0.001), respectively. Fractional iron absorption from the lpa line low in PPs (4%) was 50% higher and the total amount of iron absorbed per test meal (261 μg) was 85% higher than iron from the parent low in PPs (P < 0.001). There was no difference between the lpa beans high or low in PPs or between the parents high or low in PPs. A 90% reduction in PA leads to an increase in bioavailable iron from beans, independent of the PP concentration. The lpa mutation could be a key tool for improving iron bioavailability from beans.