Objective: The δ 13C value of human blood is an emerging novel biomarker of added sugar (AS) intake for adults. However, no free-living, community-based assessments of comparative validity of this biomarker have been conducted. The purpose of the present investigation was to determine if Healthy Eating Index-2010 (HEI-2010) score, SoFAAS score (HEI-2010 sub-component for solid fat, alcohol and AS), AS and sugar-sweetened beverage (SSB) intakes were associated with δ 13C value of fingerstick blood in a community-based sample of adults, while controlling for relevant demographics.
Design: A cross-sectional analysis of data obtained from assessments of BMI, dietary intake using 24 h recalls and a fingerstick blood sample was completed. Statistical analyses included descriptive statistics, multiple linear regression and one-way ANOVA.
Setting: Rural Southwest Virginia, U.S.A.
Subjects: Adults (n 216) aged >18 years who consumed at least 837 kJ/d (200 kcal/d) from SSB.
Results: This sample of adult participants with low socio-economic status demonstrated a mean HEI-2010 score of 43.4 (sd 12.2), mean SoFAAS score of 10.2 (sd 5.7), mean AS intake of 93 (sd 65) g/d and mean blood δ 13C value of -18.88 (sd 0.7) ‰. In four separate regression models, HEI-2010 (R 2=0.16), SoFAAS (R 2=0.19), AS (R 2=0.15) and SSB (R 2=0.14) predicted δ 13C value (all P≤0.001). Age was also predictive of δ 13C value, but not sex or race.
Conclusions: These findings suggest that fingerstick δ 13C value has the potential to be a minimally invasive method for assessing AS and SSB intake and overall dietary quality in community-based settings. Strengths, limitations and future areas of research for using an objective δ 13C biomarker in diet-related public health studies are discussed.
Keywords: Added sugar; Biomarker; Dietary assessment; Dietary quality.