August 31, 2010 — Daily consumption of artificially sweetened soft drinks may increase the risk for preterm delivery, according to the results of a Danish prospective cohort study reported in the September issue of the American Journal of Clinical Nutrition.
"Sugar-sweetened soft drinks have been linked to a number of adverse health outcomes such as high weight gain," write Thorhallur I. Halldorsson, from Statens Serum Institut in Copenhagen, Denmark, and colleagues. "Therefore, artificially sweetened soft drinks are often promoted as an alternative. However, the safety of artificial sweeteners has been disputed, and consequences of high intakes of artificial sweeteners for pregnant women have been minimally addressed."
The goal of the study was to evaluate the association between consumption of sugar-sweetened and artificially sweetened soft drinks and preterm delivery.
Participants were 59,334 women enrolled in the Danish National Birth Cohort from 1996 to 2002. With use of a food frequency questionnaire, soft drink consumption was evaluated in midpregnancy, and telephone interviews determined covariate information. The main study endpoint was preterm delivery, defined as less than 37 weeks of gestation.
Consumption of artificially sweetened carbonated and noncarbonated soft drinks was associated with an increased risk for preterm delivery (P for trend ≤ .001 for both variables). Compared with women who did not drink artificially sweetened carbonated soft drinks, the adjusted odds ratio (OR) for women who drank at least 1 serving daily was 1.38 (95% confidence interval [CI], 1.15 - 1.65), and the adjusted OR for women who drank at least 4 servings daily was 1.78 (95% CI, 1.19 - 2.66). These associations were noted in normal-weight as well as in overweight women. Increased risk was stronger for early preterm and moderately preterm delivery vs late-preterm delivery.
For sugar-sweetened carbonated or noncarbonated soft drinks, no apparent association with the risk for preterm delivery was observed.
"Daily intake of artificially sweetened soft drinks may increase the risk of preterm delivery," the study authors write. "Further studies are needed to reject or confirm these findings."
Limitations of this study include possible reverse causality, inability to implicate specific artificial sweetener(s), observational design, and unidentified or residual confounders.
"The relative consistency of our findings for carbonated and noncarbonated soft drinks and the absence of an association for sugar-sweetened soft drinks suggest that the content of artificial sweeteners might be the causal factor," the study authors conclude. "However, the replication of our findings in another experimental setting is warranted."
The European Union (EU) Integrated Research Project EARNEST supported this study. The EU project EARNEST receives financial support from the Commission of the European Communities. The Danish National Birth Cohort has been financed by the March of Dimes Birth Defects Foundation, the Danish Heart Association, the Danish Medical Research Council, and the Sygekassernes Helsefond Danish National Research Foundation, Danish Pharmaceutical Association, Ministry of Health, National Board of Health, Statens Serum Institut. The study authors have disclosed no relevant financial relationships.
Am J Clin Nutr. 2010;92:626-633