A Dual-Carbon-and-Nitrogen Stable Isotope Ratio Model Is Not Superior to a Single-Carbon Stable Isotope Ratio Model for Predicting Added Sugar Intake in Southwest Virginian Adults 1,2

• Published in: The Journal of nutrition Vol. 145; no. 6; p. 1362
• Main Authors: Hedrick, Valisa E, Zoellner, Jamie M, Jahren, A Hope, Woodford, Natalie A, Bostic, Joshua N, Davy, Brenda M
• Format: Journal Article
• Language: English
• Published: Bethesda American Institute of Nutrition 01.06.2015
• Subjects: Age; Biomarkers; Carbon; Food; Laboratories; Population; Proteins; United States > US
• ISSN: 0022-3166; 1541-6100

An objective measure of added sugar (AS) and sugar-sweetened beverage (SSB) intake is needed. The δ^sup 13^C value of finger-stick blood is a novel validated biomarker of AS/SSB intake; however, nonsweetener corn products and animal protein also carry a δ^sup 13^C value similar to AS sources, which may affect blood δ^sup 13^C values. The δ^sup 15^N value of blood has been proposed as a "correction factor" for animal protein intake. The objectives were to 1) identify foods associated with δ^sup 13^C and δ^sup 15^N blood values, 2) determine the contribution of nonsweetener corn to the diet relative to AS intake, and 3) determine if the dual-isotope model (δ^sup 13^C and δ^sup 15^N) is a better predictor of AS/SSB intake than δ^sup 13^C alone. A cross-sectional sample of southwest Virginian adults (n = 257; aged 42 ± 15 y; 74% overweight/obese) underwent dietary intake assessments and provided finger-stick blood samples, which were analyzed for δ^sup 13^C and δ^sup 15^N values by using natural abundance stable isotope mass spectrometry. Statistical analyses included ANOVAs, paired-samples t tests, and multiple linear regressions. The mean ± SD daily AS intake was 88 ± 59 g and nonsweetener corn intake was 13 ± 13 g. The mean δ^sup 13^C value was -19.1 ± 0.9[per thousand] &, which was significantly correlated with AS and SSB intakes (r = 0.32 and 0.39, respectively; P ≤ 0.01).The δ^sup 13^C value and nonsweetener corn intake and the δ^sup 15^N value and animal protein intake were not correlated. AS intake was significantly greater than nonsweetener corn intake (mean difference = 76.2 ± 57.2 g; P ≤ 0.001). The δ^sup 13^C value was predictive of AS/SSB intake (b range: 0.28-0.35; P ≤ 0.01); however, δ^sup 15^N was not predictive and minimal increases in R^sup 2^ values were observed when the value was predictive of AS/SSB intake (β range: 0.28-0.35; P ≤ 0.01); however, δ^sup 15^N was not predictive and minimal increases in R^sup 2^ values were observed when the δ^sup 15^N value was added to the model. The data do not provide evidence that the dual-isotope method is superior for predicting AS/SSB intakes within a southwest Virginian population. Our results support the potential of the δ^sup 13^C value of finger-stick blood to serve as an objective measure of AS/SSB intake. This trial was registered at clinical trials.gov as NCT02193009.