Petzke Klaus J, Boeing Heiner, Klaus Susanne, Metges Cornelia C
German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), D-14558 Nuthetal, Germany.
J Nutr. 2005 Jun;135(6):1515-20. doi: 10.1093/jn/135.6.1515.
The stable nitrogen (15N) and carbon (13C) isotopic composition of tissues reflects the isotopic pattern of food sources. We investigated whether the isotopic composition of human hair can be used as a biomarker to predict the dietary intake of animal-derived food. Hair samples were collected from subjects during a 1987-1988 German nutrition survey (VERA) in which dietary information was collected using a 7-d dietary record. Samples of 50 men and 50 women were randomly selected, in addition to 27 samples of subjects with a reported low meat intake. Isotope ratio MS was used to analyze hair bulk and amino acid-specific isotopic composition. Its relation with and feasibility for predicting animal protein intake were tested using regression analysis and cross-tabulation of observed and predicted dietary data and comparison of the individual values for the binary categories of high and low intake. 15N and 13C abundances strongly predicted relative animal protein and meat intake (R2= 0.31, P < 0.01 and R2= 0.20, P <0.01, respectively). Distinct patterns of individual hair amino acid 15N and 13C abundances were observed. In contrast to bulk values, the isotopic abundances in individual amino acids did not show discriminating ability across sex and isotope-specific categories. We conclude that hair 13C values are as predictive for animal protein consumption as hair 15N values. Bulk isotopic abundance of hair can be used as a biomarker for animal protein intake to validate dietary assessment methods provided that the correlation between isotopic abundances and dietary protein intake is verified in dietary intervention studies.
组织中稳定氮（15N）和碳（13C）的同位素组成反映了食物来源的同位素模式。我们研究了人类头发的同位素组成是否可用作生物标志物来预测动物源性食物的膳食摄入量。在1987 - 1988年德国营养调查（VERA）期间从受试者处收集头发样本，该调查使用7天饮食记录收集饮食信息。除了27名报告肉类摄入量低的受试者样本外，还随机选取了50名男性和50名女性的样本。使用同位素比率质谱仪分析头发整体和特定氨基酸的同位素组成。使用回归分析以及观察到的和预测的饮食数据的交叉列表，并比较高摄入量和低摄入量二元类别的个体值，测试其与预测动物蛋白摄入量的关系及可行性。15N和13C丰度强烈预测了相对动物蛋白和肉类摄入量（R2分别为0.31，P < 0.01和R2为0.20，P < 0.01）。观察到个体头发氨基酸15N和13C丰度的不同模式。与整体值相反，单个氨基酸中的同位素丰度在性别和特定同位素类别之间没有显示出区分能力。我们得出结论，头发13C值与头发15N值一样可预测动物蛋白的摄入量。只要在饮食干预研究中验证同位素丰度与膳食蛋白质摄入量之间的相关性，头发的整体同位素丰度就可以用作动物蛋白摄入量的生物标志物，以验证膳食评估方法。
