Associations of food group intakes with serum carbon isotope ratio values in youth: Results from 2 prospective pediatric cohort studies

Authors: COHEN, C. CATHERINE - University Of Colorado; PENG, MIA - University Of Colorado; DAVY, BRENDA - University Of Colorado; WEI, PERNG - University Of Colorado; Shankar, Kartik; DABELEA, DANA - University Of Colorado

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2024
Publication Date: 11/1/2024
Citation: Cohen, C., Peng, M., Davy, B., Wei, P., Shankar, K., Dabelea, D. 2024. Associations of food group intakes with serum carbon isotope ratio values in youth: Results from 2 prospective pediatric cohort studies. Journal of Nutrition. 155(1):293-304. https://doi.org/10.1016/j.tjnut.2024.10.052.
DOI: https://doi.org/10.1016/j.tjnut.2024.10.052

Interpretive Summary: Methods to reliably and objectively measure how much sugar-sweetened beverages (SSBs) children and teenagers drink are needed. One promising tool is the carbon isotope ratio (CIR) in blood which utilizes the natural isotopic difference of carbon isotopes in most plant based sugars. This study investigated if CIR could accurately reflect SSB intake in youth, a group whose diet and physiology differ from adults. Researchers followed two groups of children and adolescents in Colorado over several years, collecting data on their diets and measuring their serum CIR. They found that, across visits, higher SSB intake was indeed linked to a higher serum CIR in both groups. However, the study also revealed that higher meat and animal protein consumption was consistently, and sometimes even more strongly, associated with higher serum CIR. While CIR appears to be a good indicator of current SSB intake in young people, changes in SSB consumption over time did not strongly correlate with changes in CIR. These findings suggest that serum CIR could be a useful marker for recent SSB intake, but meat and animal protein intake also significantly influence this marker.

Technical Abstract: The carbon isotope ratio (CIR) is a candidate biomarker for sugar-sweetened beverage (SSB) intake in the United States. However, research specific to youth, who differ in their physiology and dietary patterns compared with adults, is lacking. We evaluated longitudinal associations of SSB intakes across childhood/adolescence with serum CIR. We also explored the relationship between other dietary intakes and serum CIR. Methods: Data were from participants in two longitudinal, pediatric cohorts in Colorado: Exploring Perinatal Outcomes among CHildren (EPOCH) study (visits at median 10 and 16 y, n = 150) and Healthy Start Study (visits at median 5 and 9 y, n = 166). Serum CIR was measured using isotope ratio mass spectrometry. Diet was assessed by food-frequency questionnaires (EPOCH) or 24-h diet recalls (Healthy Start). We assessed associations of longitudinal dietary intakes (log2-transformed, standardized) with serum CIR using linear mixed models adjusted for age, sex, and energy intake, and associations of change values between visits using linear regression models. In linear mixed models, higher SSB intake across visits was associated with higher serum CIR in both cohorts [ß (95% confidence interval (CI)): 0.11 (0.06, 0.15) in EPOCH and 0.14 (0.07, 0.21) in Healthy Start]. Higher meat intake and a higher dietary animal protein ratio were also positively associated with serum CIR in both cohorts [ß (95% CI): 0.08 (0.05, 0.12) and 0.18 (0.13, 0.23) in EPOCH; 0.08 (0.01, 0.16) and 0.28 (0.21, 0.35) in Healthy Start]. In change analyses, there were positive associations for changes in the dietary animal protein ratio between visits with changes in serum CIR in both cohorts, but not for changes in SSB intake. Our findings support serum CIR as a potential biomarker of SSB intake in youth cross-sectionally; however, there was not a strong link between change values over longer-term follow-up. Meat/animal protein intake was also consistently and, at times, more strongly associated with serum CIR.