Serum carbon isotope values change in adults in response to changes in sugar-sweetened beverage intake

Abstract

Serum carbon isotope values [13C-to-12C serum carbon isotope ratio (δ13C)], which reflect consumption of corn- and canebased foods, differ between persons consuming high and low amounts of sugar-sweetened beverages (SSBs). In this study, we determined whether serum δ13C changes in response to change in SSB intake during an 18-mo behavioral intervention trial. Data were from a subset of 144 participants from the PREMIER trial, a completed behavioral intervention (Maryland, 1998-2004). SSB intake was assessed using 2 24-h dietary recall interviews. Blinded serum samples were assayed for δ13C by natural abundance stable isotope mass spectroscopy. Multiple linear regression models with generalized estimating equations and robust variance estimation were used. At baseline, mean SSB intake was 13.8 ± 14.2 fl oz/d, and mean δ13C serum value was -19.3 ± 0.6 units per mil (designated ‰). A reduction of 12 oz (355 mL)/d SSB (equivalent to 1 can of soda per day) was associated with 0.17‰ (95% CI: 0.08‰, 0.25‰; P < 0.0001) reduction in serum δ13C values over 18 mo (equivalent to a 1% reduction in δ13C from baseline). After adjusting for potential confounders, a reduction of 12 oz/d SSB (equivalent to 1 can of soda per day), over an 18-mo period, was associated with 0.12‰(95% CI: 0.01‰, 0.22‰; P = 0.025) reduction in serum δ13C. These findings suggest that serum δ13C can be used as a measure of dietary changes in SSB intake. © 2014 American Society for Nutrition.