Evaluation of a novel isotope biomarker for dietary consumption of sweets

Carbon isotopic signatures ("δ¹³C") might reflect consumption of corn- and cane-based sweeteners. The authors hypothesized that the δ¹³C value of human serum is higher for individuals with high versus low intakes of corn- and cane-based sweeteners (measured as sweetened beverage intake). They conducted a cross-sectional study within the Atherosclerosis Risk in Communities Magnetic Resonance Imaging study (Maryland, 2005-2006). Diet was assessed by food frequency questionnaire, and blinded serum samples were assayed by natural abundance stable isotope mass spectroscopy. Studied were 186 participants (53% male; mean age, 71 years; mean body mass index, 30 kg/m²). Serum δ¹³C values for individuals with high sweetened beverage intakes were significantly higher than for those with low intakes (-19.15‰ vs. -19.47‰, P < 0.001). Serum δ¹³C value increased 0.20‰ for every serving/day of sweetened beverages (P < 0.01). The association between sweetened beverages and serum δ¹³C value remained significant after adjustment for confounding by corn-based product intake (P < 0.001). Serum δ¹³C values were also associated with waist circumference, body mass index, and waist-to-hip ratio. This study provides the first known evidence that the δ¹³C value of human serum differs between persons consuming low and high amounts of sweets. Within the proper framework, serum δ¹³C value could be developed into an objective biomarker promoting more reliable assessment of dietary sweets intake.