Sandström B, Almgren A, Kivistö B, Cederblad A
Department of Clinical Nutrition, University of Gothenburg, Sweden.
J Nutr. 1989 Jan;119(1):48-53. doi: 10.1093/jn/119.1.48.
The effect of increasing levels of various protein sources on zinc absorption from a legume-based meal was studied in humans with the use of a radionuclide technique. The meals were extrinsically labelled with 65Zn and absorption was determined from measurements of the whole-body retention of the isotope. The mean fractional zinc absorption for the 13 meals was 24.7 +/- 6.9% and was only influenced by the protein content of the meal to a limited extent (r = 0.45). However, the amount of zinc absorbed from the meals was strongly correlated with both the protein (r = 0.85) and zinc content (r = 0.86): 5.9 +/- 1.7 mumol of zinc was absorbed from the basal bean meal which had the lowest protein content; the addition of low zinc chicken doubled the protein content and increased zinc absorption to 10.3 +/- 2.0 mumol; the addition of zinc-rich beef also doubled the protein content, however, zinc absorption was increased to 15.9 +/- 4.7 mumol. It is concluded that the zinc content of the main protein source of the diet determines the amount of zinc absorbed to a large extent. However, relatively small amounts of animal protein can significantly improve the value of a legume-based meal as a source of zinc.
利用放射性核素技术，在人体中研究了增加不同蛋白质来源水平对豆类膳食中锌吸收的影响。这些膳食用65Zn进行体外标记，并通过测量同位素在全身的滞留量来确定吸收情况。13份膳食的锌平均吸收分数为24.7±6.9%，且仅在有限程度上受膳食蛋白质含量的影响（r = 0.45）。然而，从膳食中吸收的锌量与蛋白质（r = 0.85）和锌含量（r = 0.86）均密切相关：蛋白质含量最低的基础豆粕中吸收了5.9±1.7 μmol的锌；添加低锌鸡肉使蛋白质含量翻倍，锌吸收量增加到10.3±2.0 μmol；添加富含锌的牛肉也使蛋白质含量翻倍，然而，锌吸收量增加到15.9±4.7 μmol。得出的结论是，饮食中主要蛋白质来源的锌含量在很大程度上决定了锌的吸收量。然而，相对少量的动物蛋白可显著提高豆类膳食作为锌源的价值。
