May 10, 2016 — In the article “Association Between Artificially Sweetened Beverage Consumption During Pregnancy and Infant Body Mass Index,” published in May 2016 in JAMA Pediatrics, researchers from the University of Manitoba suggest that daily consumption of artificially sweetened beverages by women during pregnancy may increase their child’s future risk of obesity. However, several important factors should be considered when reviewing the article and its conclusion.
Study was Observational, not Causal
The observational study is based on self-reported intake of various foods and beverages by mothers during their pregnancy and the baby’s weight at one year of age. The study uses data for women and their infants participating in the Canadian Healthy Infant Longitudinal Development (CHILD) Study. The research team used this self-reported data to determine if there was an association between various components of maternal lifestyle and diet with their baby’s body weight. The study suggests that a baby’s body mass index (BMI) at one year of age is associated with a mother’s consumption of beverages sweetened with low-calorie sweeteners during pregnancy. Importantly, the authors reported that mothers who consumed low-calorie sweetened beverages were also likely to exhibit certain risk factors which are also associated with future childhood obesity, including pre-pregnancy obesity, tobacco use, and early introduction of solid foods to the infant.
Study Ignores Safety Record for Pregnant Women with Low Calorie Sweeteners
While the results are intriguing, the research team failed to mention that the use of low-calorie sweeteners during pregnancy has been well studied both in humans and animals. “Before a low-calorie sweetener may be used in food or beverage, it must be determined by relevant regulatory bodies to be safe for all populations, including special populations such as the elderly, children, and pregnant and nursing women. These safety assessments include an evaluation of possible effects of low-calorie sweeteners during pregnancy and have continued to show that these sweeteners are safe for pregnant women and their children,” says Robert Rankin, President of the Calorie Control Council.
Study Neglects to Consider Tightly Controlled Fetal Nutrition During Pregnancy
Researching the role of a mother’s diet during pregnancy has a long history, with much of the knowledge centering on how undernutrition can adversely affect pregnancy. The provocative and relatively new hypothesis that the risk for obesity may begin during fetal life has received a lot of attention in the last two decades. While the idea has become quite popular and many scientists are researching the topic, the current study by Azad et al. has limitations that raise more concern than provide hard evidence.
The authors claim that their research findings suggest diet beverage consumption during pregnancy is related to the baby’s body weight at one year. While it is common for mathematical corrections to be made to account for known factors which affect body weight in these types of observational studies, the researchers failed to address the unique nutrition of a fetus as they develop their model. It is well known that the transfer of numerous nutrients, fluid, and other food components to the fetus is tightly controlled. Understanding this biological regulation is essential for any discussion regarding the ability of a food or beverage to affect infant growth.
Study Doesn’t Consider Whole Diet
Furthermore, this study only associated those sweeteners used in “diet soft drinks or pop” and “artificial sweetener added to tea or coffee,” which represents a small portion of the mother’s diet. Rather, the whole diet should have been evaluated by the researchers to get a clearer picture of the possible effects of maternal nutrition on their baby’s growth. Low-calorie sweeteners can help pregnant women avoid excess calories, leaving room for consumption of nutritious foods and beverages. Excess weight gain during pregnancy can be harmful to both the mother and developing baby. Research shows that overweight and obesity as well as diabetes can negatively affect pregnancy outcomes and a child’s future weight gain and risk for obesity. This is particularly important as the prevalence of diabetes during pregnancy, known as gestational diabetes mellitus (GDM), is as high as 9.2% and pre-pregnancy obesity prevalence continues to increase. The American Congress of Obstetricians and Gynecologists (ACOG) recognizes the importance of appropriate weight gain during pregnancy. Weight gain during pregnancy can affect the immediate and future health of a woman and her infant, so women who are pregnant or plan to become pregnant should discuss their current weight and weight gain with a healthcare provider.
Other Health Groups Support Low Calorie Sweeteners During Pregnancy
Leading health groups, including the Academy of Nutrition and Dietetics (AND) and American Diabetes Association (ADA), support the use of low-calorie sweeteners during pregnancy to assist with control of calories and weight management. Further, global regulatory agencies have studied the use of low-calorie sweeteners in special populations, including pregnant and nursing women, and deemed them to be safe.