Study on Artificially Sweetened Beverages and Preterm Delivery Is Misleading
ATLANTA (August 30, 2008) — Findings presented in “Association between intake of artificially sweetened and sugar-sweetened beverages and preterm delivery: a large prospective cohort study” are weak and misleading.
The Calorie Control Council cites the following as serious limitations of the study:
- No true association between the intake of artificially sweetened beverages and preterm delivery was found, although the authors reported the contrary. The relationship presented between the consumption of artificially sweetened beverages and preterm delivery was extremely weak. Further, the authors misinterpreted the statistics, stating that the association found was small but significant, when in fact it was on the edge and not what statisticians would consider to be significant. (i.e. – The confidence interval (CI) should not include 1 to be able to consider a finding significant.)
- The association between the intake of artificially sweetened beverages and preterm delivery was due to other factors, not low calorie sweeteners. The relationship presented between the consumption of artificially sweetened beverages and preterm delivery was extremely weak, and when other factors such as age, history of preterm delivery and sugar-sweetened beverage intake were controlled for, the relationships in most categories were no longer statistically significant. This suggests that other factors are responsible for the increased risk of preterm delivery, not artificial sweeteners.
- The results of the study do not seem to be biologically plausible. It is peculiar that the risk of preterm delivery reported by the authors was only increased in the late preterm delivery group, but not in the moderate or early preterm group. Intuitively, one would think that if there was a risk, it would be more likely to affect the more vulnerable group. Further, it does not seem logical that women consuming 1-6 servings of sugar-sweetened beverages per day would have a lower risk of early preterm delivery than those consuming more than 4 servings/day or less than one serving/week as the authors reported.
- Other factors may have influenced the findings. The authors controlled for some things known to impact the risk of preterm delivery, but admitted there might be other factors for which they did not control. For example, the study did not control for other dietary habits or socioeconomic status, both of which may have influenced preterm delivery risk.
- The study cannot determine cause and effect. Finally, because the study was observational, it is impossible to ascertain if the artificially sweetened beverages were the cause of any of the findings seen. Even the authors said other variables could be influencing the results. Variables such as additional dietary factors, socioeconomic factors or other factors that increase the risk of premature births (e.g. – certain infections, high blood pressure, clotting disorders, bleeding, certain birth defects in the baby, being pregnant with a single fetus that is the result of in vitro fertilization, anemia, stress, depression, lack of support, etc.) were not considered by the authors and could have had an effect.
- The study had numerous limitations. The authors noted several limitations of the study: 1) study subjects could have incorrectly reported what they ate; 2) study subjects do not necessarily represent everyone in Norway, much less other parts of the world; 3) factors other than the ones for which researchers controlled could have affected the relationship.
The use of low-calorie sweeteners in pregnancy has been well studied both in humans and in animals. Before approving the currently available low-calorie sweeteners, regulatory bodies world-wide determined that the low-calorie sweeteners are safe for all populations, including special groups such as the elderly, children, and pregnant and nursing women. Further, leading health groups such as the Academy of Nutrition and Dietetics and American Diabetes Association support the safe use of low-calorie sweeteners during pregnancy.
Importantly, in 2011 both the European Food Safety Authority (EFSA) and the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) confirmed that low calorie sweeteners are safe for pregnant women. Additionally, in 2011, EFSA concluded that there was no available evidence to show that consumption of artificially sweetened soft drinks led to preterm delivery.