Discipline of Nutrition & Metabolism, School of Molecular Bioscience G08, University of Sydney, Sydney, NSW, 2006, Australia.
Biol Trace Elem Res. 2012 Nov;149(2):135-42. doi: 10.1007/s12011-012-9408-7. Epub 2012 Apr 21.
Phytic acid is a major determinant of zinc bioavailability. Little is known about phytic acid intakes or indices of zinc bioavailability in type 2 diabetes mellitus (DM), a condition that predisposes to zinc deficiency. The aim of this cross-sectional study was to measure and explore the relationships among phytic acid intake, zinc bioavailability, and molecular markers of zinc homeostasis in 20 women with DM compared to 20 healthy women. The phytate/zinc, (calcium)(phytate)/zinc, and (calcium + magnesium)(phytate)/zinc molar ratios were used to indicate zinc bioavailability. Plasma zinc concentrations and zinc transporter (ZnT1, ZnT8, and Zip1) gene expression in mononuclear cells were measured. Participants with DM consumed 1,194 ± 824 mg/day (mean ± SD) phytic acid, an amount similar to the intake of healthy women (1,316 ± 708 mg/day). Bread products and breakfast cereals contributed more than 40 % of the phytic acid intake in each group. A positive relationship was observed in all participants between phytic acid and dietary fiber (r = 0.6, P < 0.001) and between dietary fiber and the (calcium)(phytate)/zinc ratio (r = 0.5, P < 0.001). Compared to the healthy group, the messenger RNA ratio of ZnT1 (zinc export) to Zip1 (zinc import) was lower in participants with DM, which may indicate perturbed zinc homeostasis in the disorder. The plasma zinc concentration was not predicted by age, body mass index, health status, zinc bioavailability, or zinc transporter expression. Healthy and diabetic women consume phytic acid in amounts that are likely to decrease the bioavailability of dietary zinc. Recommendations to consume greater amounts of dietary fiber, much of which is associated with phytate, increase the risk of zinc deficiency.
植酸是锌生物利用度的主要决定因素。在 2 型糖尿病（DM）中，人们对其植酸摄入量或锌生物利用度的指数知之甚少，这种疾病容易导致锌缺乏。本横断面研究的目的是测量并探讨 20 名糖尿病女性与 20 名健康女性之间的植酸摄入量、锌生物利用度和锌稳态分子标志物之间的关系。使用植酸/锌、（钙）（植酸）/锌和（钙+镁）（植酸）/锌摩尔比来表示锌生物利用度。测量了单核细胞中的血浆锌浓度和锌转运体（ZnT1、ZnT8 和 Zip1）基因表达。患有 DM 的参与者每天摄入 1194 ± 824 毫克（平均值 ± 标准差）植酸，这一数量与健康女性的摄入量相似（1316 ± 708 毫克/天）。面包产品和早餐麦片在每个组的植酸摄入量中均占 40%以上。所有参与者均观察到植酸与膳食纤维之间呈正相关（r = 0.6，P < 0.001），膳食纤维与（钙）（植酸）/锌比之间呈正相关（r = 0.5，P < 0.001）。与健康组相比，患有 DM 的参与者中 ZnT1（锌输出）与 Zip1（锌输入）的信使 RNA 比值较低，这可能表明该疾病中锌稳态失调。血浆锌浓度不受年龄、体重指数、健康状况、锌生物利用度或锌转运体表达的影响。健康和糖尿病女性摄入的植酸量可能会降低膳食锌的生物利用度。建议增加膳食纤维的摄入量，其中大部分与植酸有关，这会增加锌缺乏的风险。
