Reddy M B, Hurrell R F, Juillerat M A, Cook J D
Department of Medicine, Kansas University Medical Center, Kansas City 66160-7402, USA.
Am J Clin Nutr. 1996 Feb;63(2):203-7. doi: 10.1093/ajcn/63.2.203.
The inhibiting effect of phytate on nonheme-iron absorption from different protein sources was examined in human subjects using extrinsic radioiron labeling. A drink containing maltodextrose and corn oil was used as a control meal to which was added sufficient sodium phytate to provide 300 mg phytic acid and/or various protein sources. The proteins were selected to cover a broad range of effects on bioavailability and included egg white, meat, and phytate-free soy protein. When sodium phytate alone was added, there was a pronounced 83-90% reduction in mean absorption in separate studies with a composite average decline of 86%. Despite a wide range in absorption from meals containing the three protein sources, a remarkably similar relative inhibition was observed when sodium phytate was added. No significant difference in the inhibiting effect of phytate could be detected with additions ranging from the equivalent of 50-300 mg phytic acid to a meal containing egg white as the protein source. Our studies found no evidence that the inhibiting effect of phytate depends on the protein composition of the meal.
利用外源性放射性铁标记法，在人体受试者中研究了肌醇六磷酸对不同蛋白质来源中非血红素铁吸收的抑制作用。以含有麦芽糊精和玉米油的饮料作为对照餐，向其中添加足量的肌醇六磷酸钠，以提供300毫克植酸和/或各种蛋白质来源。选择这些蛋白质是为了涵盖对生物利用度的广泛影响，包括蛋清、肉类和无肌醇六磷酸的大豆蛋白。单独添加肌醇六磷酸钠时，在单独的研究中，平均吸收率显著降低了83% - 90%，综合平均下降了86%。尽管含这三种蛋白质来源的餐食的铁吸收率范围很广，但添加肌醇六磷酸钠时观察到相对抑制作用非常相似。当向以蛋清为蛋白质来源的餐食中添加相当于50 - 300毫克植酸的量时，未检测到肌醇六磷酸抑制作用的显著差异。我们的研究没有发现证据表明肌醇六磷酸的抑制作用取决于餐食的蛋白质组成。
