Journal article
The carbon isotope ratio of alanine is a biomarker of added sugar and sugar-sweetened beverage intakes: a pooled analysis of four studies
The American journal of clinical nutrition, Vol.122(6), pp.1769-1777
12/2025
DOI: 10.1016/j.ajcnut.2025.09.049
PMCID: PMC12668467
PMID: 41047130
Abstract
The alanine carbon isotope ratio (Ala CIR) biomarker was positively associated with added sugar (AS) and sugar-sweetened beverage (SSB) intake in multiple studies from the USA. Association strengths varied, and Ala CIR was also correlated with protein source in certain studies.
To examine Ala CIR associations with AS and SSB intake and animal protein ratio (animal protein/total protein, APR), and adjustment for APR, by pooling data from 4 previous studies.
We pooled diet and biomarker data from 4 studies (n=346). These included a cross-sectional study of Yup'ik Alaska Native adults (n=62), a 12-wk randomized controlled feeding study in men (n=32), a 2-wk habitual intake controlled feeding study in postmenopausal women (n=153), and a 15-d habitual intake controlled feeding study of adults (n=99). We estimated correlations between amino acid CIRs and diet, and performed multivariable regression of Ala CIR on standardized intake variables to determine simultaneous associations with AS (g/d) or SSBs (servings/d) and APR. We included study by intake interactions to allow for heterogeneity among studies. We then ran models where leucine (Leu) CIR was included to adjust for APR.
There were positive correlations (95% CIs) between Ala CIR and AS intake [r=0.54 (0.46, 0.61)], log-SSB intake [r=0.63 (0.56, 0.69)], and APR [r=0.32 (0.22, 0.41)]. Study-specific slopes for the relationship between Ala CIR and AS or SSB intake were similar in models with and without adjustment for APR. Across studies, slopes ranged from 0.34 (0.08, 0.61) to 1.75 (1.29, 2.20) for AS intake in models with APR and from 0.35 (0.01, 0.68) to 1.11 (0.81, 1.40) for SSB intake in models with APR. Replacing APR with Leu CIR resulted in similar slopes between Ala CIR and AS/SSB intake.
The Ala CIR is a robust biomarker of AS/SSB intake. Potential associations with APR can be adjusted for using a simultaneously-measured biomarker.
(DBD study) clinicaltrials.gov/NCT01237093; (NPAAS) clinicaltrials.gov/NCT00000611.
Details
- Title: Subtitle
- The carbon isotope ratio of alanine is a biomarker of added sugar and sugar-sweetened beverage intakes: a pooled analysis of four studies
- Creators
- Jessica J Johnson - University of Alaska FairbanksSambit Ghosh - University of Alaska FairbanksPamela A Shaw - Kaiser Permanente Washington Health Research InstituteMarian L Neuhouser - Fred Hutch Cancer CenterJohanna W Lampe - Fred Hutch Cancer CenterLesley F Tinker - Fred Hutch Cancer CenterRoss L Prentice - Fred Hutch Cancer CenterNatasha Tasevska - Arizona State UniversityLaurence S Freedman - Sheba Medical CenterBert B Boyer - Oregon Health & Science UniversityScarlett E Hopkins - Oregon Health & Science UniversitySarah H Nash - University of IowaSusanne B Votruba - National Institute of Diabetes and Digestive and Kidney DiseasesJonathan Krakoff - National Institute of Diabetes and Digestive and Kidney DiseasesDiane M O'Brien - University of Alaska Fairbanks
- Resource Type
- Journal article
- Publication Details
- The American journal of clinical nutrition, Vol.122(6), pp.1769-1777
- DOI
- 10.1016/j.ajcnut.2025.09.049
- PMID
- 41047130
- PMCID
- PMC12668467
- NLM abbreviation
- Am J Clin Nutr
- ISSN
- 1938-3207
- eISSN
- 1938-3207
- Publisher
- Elsevier; NEW YORK
- Grant note
- National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services: 75N92021D00001, 75N92021D00002, 75N92021D00003, 75N92021D00004, 75N92021D00005, R01CA119171, P30 CA015704, P30DK035816 National Cancer Institute: U01 CA197902 National Institute of Digestive, Diabetes and Kidney Diseases: R01 DK109946 National Center for Research ResourcesNational Institute of General Medical Sciences: P20RR016430 NIH National Institute of Diabetes and Digestive and Kidney Diseases: R01DK07442 Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health: P20GM103395
The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services through contracts 75N92021D00001, 75N92021D00002, 75N92021D00003, 75N92021D00004, and 75N92021D00005, and NPAAS is funded by R01CA119171, P30 CA015704, and P30DK035816. The AZ feeding study was funded by the National Cancer Institute U01 CA197902. The DBD study was funded by the National Institute of Digestive, Diabetes and Kidney Diseases R01 DK109946 and intramural funds. The CANHR study was supported by the National Center for Research Resources and the National Institute of General Medical Sciences P20RR016430 and NIH National Institute of Diabetes and Digestive and Kidney Diseases R01DK07442. The pooled analysis was further supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103395. The content is solely the responsibility of the authors and does not necessarily reflect the official views of the NIH.
- Language
- English
- Electronic publication date
- 10/03/2025
- Date published
- 12/2025
- Academic Unit
- Epidemiology; Community and Behavioral Health
- Record Identifier
- 9984969242702771
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