A new study found that babies of women who drank artificially-sweetened beverages while pregnant were 10 percent more likely to be overweight by their first birthday. The study, published in JAMA Pediatrics, is more evidence that artificial sweeteners are not innocuous and may increase the risk of obesity and metabolic diseases.1
Some studies have shown that eating artificial sweeteners may increase the risk of obesity, yet little is known about the effects of exposure to artificial sweeteners during gestation.
Meghan Azad, PhD, assistant professor, pediatrics and child health, at the University of Manitoba in Canada, has been studying factors, like breastfeeding, which affect the gut microbiome in infants, but artificial sweeteners have never been studied, despite the fact that more than 30 percent of women report consuming artificially sweetened beverages during pregnancy, according to several studies from Norway2 and Denmark.3
The researchers examined data from the Canadian Healthy Infant Longitudinal Development (CHILD) study to see if drinking artificially-sweetened beverages during pregnancy affected the weight of infants. They looked at consumption of soda and iced tea type drinks as well as coffee and tea.
They found that drinking one or more artificially-sweetened beverages daily during pregnancy was associated with a higher body mass index of babies at one year of age. After the authors controlled for factors like maternal obesity, diet quality and sugar intake, daily consumption of artificially-sweetened beverages was associated with a two-fold higher risk of babies being overweight by their first birthday. The incidence of overweight among babies born to fake-sugar drinking moms was 10.4 percent compared to 4.5 percent among non drinkers.
“This provides more evidence that artificial sweeteners may have this counterintuitive results,” says Azad.
In fact, even though these women consumed significantly less sugar-sweetened drinks, those who drank the artificially-sweetened drinks frequently did not have a lower total calorie intake. “Sometimes you drink a Diet Coke, and you say, now I can have that cake,” says Azad. Women who drink large amounts of artificially-sweetened beverages tend to have a poorer quality diet, she says.
Overall, 29.5 percent of mothers consumed artificially sweetened drinks during pregnancy, while 5.1 percent had these drinks daily. On the other hand, 77.2 percent of pregnant women consumed sugar-sweetened drinks, with 23.4 percent did so daily.
Several theories have been put forward to explain the paradox. One suggests that though artificial, the sweeteners alter glucose metabolism, another theory suggests that fake sugar disrupts the bacteria in the gut, and yet another says that it leads to dysfunctional satiety mechanisms.4,5 This study lends evidence to the microbiome theory.
“Though the study did not look at the mechanism, it may be that the mother’s consumption of artificially-sweetened drinks changes her own gut microbiome, and they pass that onto their infants,” says Azad. Animal studies have shown that consumption of artificial sweeteners in pregnancy predisposes offspring to obesity, a stronger preference for sweet foods, increased postnatal weight gain, altered lipid profiles, and increased insulin resistance in adulthood.1
Azad is following up with the babies at three years and five years of age to see if the changes linger. “At this stage, it certainly is a preliminary finding. But the safest choice for pregnant women is to consume water. There’s no nutritional benefit to artificially sweetened drinks,” she says.
Mark A. Pereira, PhD, a researcher at the School of Public Health, University of Minnesota, in Minneapolis, co-wrote an editorial that accompanied the study. The editorial pointed out that pregnant women need more fluid than nonpregnant women, which raises the temptation to drink sweetened drinks. But he advised women to drink water and avoid sweeteners in coffee and tea, until more safety data are available.
1. Association Between Artificially Sweetened Beverage Consumption During Pregnancy and Infant Body Mass Index. Meghan B. Azad, Ph.D., JAMA Pediatrics, May 9, 2016. http://archpedi.jamanetwork.com/article.aspx?articleID=2521471. Accessed May 18, 2016.