Center for Alaska Native Health Research, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA.
J Nutr. 2013 Jun;143(6):878-84. doi: 10.3945/jn.112.172999. Epub 2013 Apr 24.
An objective dietary biomarker would help clarify the contribution of sugar-sweetened beverage (SSB) intake to obesity and chronic disease risk. Previous studies have proposed the carbon isotope ratio (δ(13)C) as a biomarker of SSB intake but found associations that were of modest size and confounded by other components of the diet. We investigated whether the δ(13)C values of nonessential amino acids (δ(13)CNEAA) in RBCs could provide valid biomarkers that are more specific to SSBs. We assessed the associations of RBC δ(13)CNEAA with SSB intake in a study population of 68 Yup'ik people, using gas chromatography/combustion/isotope ratio mass spectrometry to measure δ(13)CNEAA and four 24-h dietary recalls to assess intake. Among RBC nonessential amino acids, alanine δ(13)C (δ(13)Calanine) was strongly correlated with intake of SSBs, added sugar, and total sugar (r = 0.70, 0.59, and 0.57, respectively; P < 0.0001) but uncorrelated with other dietary sources of elevated δ(13)C. We also evaluated whether sweetener intake could be noninvasively assessed using hair δ(13)Calanine in a subset of the study population (n = 30). Hair δ(13)Calanine was correlated with RBC δ(13)Calanine (r = 0.65; P < 0.0001) and showed similar associations with SSB intake. These results show that δ(13)Calanine in RBCs provides a valid and specific biomarker of SSB intake for the Yup'ik population and suggest RBCs and hair δ(13)Calanine as candidate biomarkers of SSB intake for validation in the general U.S. population. Ultimately, these biomarkers could clarify our understanding of whether and how SSB intake contributes to chronic disease.
一种客观的饮食生物标志物将有助于阐明含糖饮料（SSB）摄入对肥胖和慢性病风险的贡献。先前的研究提出了碳同位素比值（δ（13）C）作为 SSB 摄入量的生物标志物，但发现的关联规模适中且受到饮食其他成分的混淆。我们研究了 RBC 中非必需氨基酸（δ（13）CNEAA）的 δ（13）C 值是否可以提供更特异于 SSB 的有效生物标志物。我们使用气相色谱/燃烧/同位素比质谱法测量 δ（13）CNEAA，并使用四种 24 小时膳食回忆评估摄入量，在 Yup'ik 人群的研究人群中评估 RBC δ（13）CNEAA 与 SSB 摄入量的相关性。在 RBC 中非必需氨基酸中，丙氨酸 δ（13）C（δ（13）Calanine）与 SSB、添加糖和总糖的摄入量呈强相关（r = 0.70、0.59 和 0.57；P < 0.0001），但与其他升高的 δ（13）C 的饮食来源无关。我们还评估了在研究人群的一部分（n = 30）中是否可以使用头发 δ（13）Calanine 非侵入性地评估甜味剂摄入量。头发 δ（13）Calanine 与 RBC δ（13）Calanine 相关（r = 0.65；P < 0.0001），并且与 SSB 摄入量呈相似的关联。这些结果表明，RBC 中的 δ（13）Calanine 为 Yup'ik 人群提供了 SSB 摄入量的有效和特异生物标志物，并表明 RBC 和头发 δ（13）Calanine 是 SSB 摄入量的候选生物标志物，可在美国一般人群中进行验证。最终，这些生物标志物可以阐明我们对 SSB 摄入量是否以及如何导致慢性病的理解。
