Sweet drinks like soda and flavored juice beverages have been
linked to a number of health problems, including obesity, diabetes, and heart failure.
While much attention has been paid to the negative effects of added sugar, some studies suggest consumption of artificial sweetener may be harmful too.
But little research has been done on pregnant women consuming such drinks and
the impact it may have on their children. Now, a new report published in JAMA
Pediatrics suggests that when women drink artificially sweetened beverages on a daily basis during
pregnancy, their children are twice as likely to be overweight as infants.
For the study, Meghan B. Azad, Ph.D., of the University of Manitoba in
Winnipeg, Canada and her colleagues examined over 3,000 mother-infant pairs.
They asked the women to fill out a food questionnaire during pregnancy,
including questions on how often they drank artificially sweetened beverages,
such as diet soda and tea or coffee with artificial sweetener added, and
sugar-sweetened drinks, such as regular soda or coffee or tea with sugar or
honey. The researchers followed up by measuring infant body mass index (BMI) when the children were a year
old.
An analysis of the data showed that daily consumption of artificially
sweetened beverages was associated with a two-fold increase in the risk of an
infant being overweight at 1 year of age.
The researchers controlled for a number of other factors that could have
influenced the children's weight, including maternal obesity, diabetes, and
general diet quality.
No association was seen with sugar-sweetened beverages. This finding surprised the
researchers somewhat, but Azad notes that this in no way means sugary drinks are
a better choice.
"We didn't find an independent association with the sugar-sweetened beverages
but we did find an association with total calorie consumption," she explained.
"Before correcting for total calories, we did see a pattern where more
sugar-sweetened beverages were associated with a higher risk of overweight in
the infants. So, sugar sweetened beverages do appear to have an impact, but this
is explained by the calories they contain."
The results suggest then that there may be something about the artificially
sweetened beverages specifically — such as certain chemicals or additives used
— that might result in infant weight gain. While the study did not look at
potential mechanisms behind the results, Azad has some theories.
"There is some evidence that consuming artificial sweeteners at least in adults changes the microbiome," she said. "We know that our gut bacteria are
important for a variety of health issues, including our metabolism. Bacteria
help us digest the food we eat and they play a role in how much calories we
extract from that food. And so if these artificial sweeteners are changing the
mom's microbiome, which then gets passed on to the baby, that might be one mechanism."
Another possibility is that artificial sweeteners disrupt metabolism in a different way.
"Our bodies have evolved to respond to sugar in a certain way, and some of
these responses are triggered by the perception of sweet taste," she said. "With
artificial sweeteners, we get the perception of sweet taste without any actual
sugar to metabolize. There's some evidence in adults that routinely consuming
artificial sweeteners may disrupt or 'reprogram' our metabolism, leaving us more
at risk for obesity and related complications."
This might in turn be happening in infants of moms who consumed high levels
of artificial sweeteners during pregnancy.
The authors note that the study is limited in several important ways,
including that it only shows an association and does not prove a
cause-and-effect relationship. There is also the possibility that the
participants may have misreported how often they drank sweet beverages.
In an accompanying editorial, Mark A. Pereira, Ph.D., of the University of
Minnesota, and Matthew W. Gillman, MD, of Harvard Medical School, caution that
the study is still preliminary. "Any microbiome-related mechanism is
speculative," they write, "and other mechanisms, which would need to account for
how maternal consumption of ASBs [artificially sweetened beverages] is
transduced into an obesogenic tendency in the fetus, are not apparent."
Yet, despite the limitations, they say the findings warrant further
study.
Furthermore, they write, the results "remind us that [artificially sweetened
beverages] yield uncertain benefits for the mother and raise the prospect of
risk for her child. Until more safety data are available, pregnant women should
consider (safe) water for proper hydration and as the beverage of choice."
