Gestational Diabetes Linked to Sugar-Sweetened Sodas

Gestational Diabetes is a type of diabetes that occurs only during pregnancy and can have serious consequences for both mother and child. Those consequences can include babies that are large for their gestational age, thus increasing the risk of Caesarean section or birth injuries, but also respiratory distress in those infants, low blood sugar, and as they get older, an increased risk of obesity and type 2 diabetes (Mayo Clinic).

Mothers who develop Gestational diabetes during one pregnancy are at a higher risk of pre-eclampsia (a life-threatening condition) in the current pregnancy and are also more likely to develop Gestational diabetes in later pregnancies. Further, they are more likely to develop diabetes or high blood pressure later in life.

We know that a healthier diet both before becoming pregnant and during pregnancy will help you avoid gestational diabetes, as will maintaining a healthy pre-pregnancy weight and getting regular exercise. There is some evidence to suggest that pregnant women would be wise to avoid fried foods as well as avoiding sugar-sweetened beverages, but the strength of the evidence against sugar-sweetened beverages has been limited - until now.

Researchers in Spain utilized data gathered through the SUN (Seguimiento Universidad de Navarra) project - a long term, large scale prospective study of male and female Spaniards that began in 1999 and continues through the present day (Clin Nutr 2018;37(2):638-645). Participants are graduates of universities in Spain and are surveyed every two years regarding their demographic, dietary, health, and exercise habits. The authors administer a food-frequency questionnaire specifically created and validated for Spanish residents, and have checked the validity of demographic information (such as height, weight, education, and physical activity) in a representative portion of the surveyed group so that they know that responses from the whole group are likely to be accurate.

To assess the impact of consuming sugar-sweetened beverages on pregnancy, the authors identified all women who responded to the survey administered just prior to March 2013 or in December 2015 who identified themselves as pregnant at the time of either survey. They also excluded women who reported having Gestational diabetes in a previous pregnancy, resulting in a group of 3,396 women.

The authors initially focused on the women's consumption of sugar-sweetened beverages and compared the level of consumption in women who were verifiably diagnosed with Gestational diabetes with those women who were not diagnosed with Gestational diabetes.

Note that even those women who drank the highest number of sugar sweetened beverages actually drank comparatively little by American standards: the researchers grouped the levels of sugar sweetened beverage consumption into four increasing levels, from the lowest level of less than 1 (6-ounce) serving per month to the highest level of 2 or more servings per week. (Compare that to those not-in-the-least-bit-unusual people here in the United States who regularly consume 2 or more cans of sugar sweetened sodas per day.)

The authors found that after controlling for pre-pregnancy Body Mass Index, smoking status, level of physical activity, family history of diabetes, whether they had diagnosed heart disease or hypertension, and Mediterranean Diet score, those women who drank just 1 or more sugar sweetened soft drinks per day prior to pregnancy were more than twice as likely to develop Gestational diabetes than those women who drank, on average, less than one serving of sugar sweetened soft drinks per day.

What this means for you

If you are pregnant or are thinking about becoming pregnant, this research suggests that it would be wise to avoid sugar-sweetened beverages for both your health and that of your child. While this particular research was limited to college-educated Caucasian women, and thus should be applied with caution to other groups of women, it's clear that sugar sweetened beverages aren't good for you for reasons other than their effect on your pregnancy or your unborn child. While this research showed no effect of non-caloric (diet) soft drinks on Gestational diabetes risk, your best and healthiest bet is still water.

First posted: June 20, 2018