Gestation diabetes mellitus (GDM), defined as diabetes with its onset during pregnancy, is the most common medical complication of pregnancy and childbirth. Obesity increases the risk of developing GDM.  Medical nutrition therapy, which uses nutrients and whole foods in the management of disease, is the cornerstone of GDM management.  However, there is little information regarding optimal diets and foods to reduce risk and adverse outcomes of GDM and therefore more trials in high-risk women are warranted.  In particular, plant-based diets that are rich in phenolic compounds deserve attention in GDM, especially in high-risk women with low habitual consumption of fruits and vegetables.

To examine the effects of whole blueberry and soluble fiber supplementation on cardiometabolic profiles in women at high risk of developing GDM, Arpita Basu (University of Nevada at Las Vegas) and colleagues recruited 34 women during early-stage pregnancy.  Adult women at high risk of GDM were enrolled in the study if they had BMI >30 (kg/m2). Participants were randomly assigned to 1 of the following 2 groups for 18 wk: 1) 280 g whole blueberries and 12 g soluble fiber per day (intervention) and 2) standard prenatal care (control). Participants in the dietary intervention group were provided biweekly supplies of frozen blueberries and soluble fiber as partially hydrolyzed guar gum.  Anthropometrics, blood pressure, and blood samples were collected at baseline (< 20 weeks), midpoint (24-28 weeks), and end (32-36 weeks) of gestation.

Study results, published in The Journal of Nutrition, show that blueberry and soluble fiber supplementation improved risk factors for GDM, especially excess maternal weight gain and cardiometabolic profiles in obese women. Maternal weight gain was significantly lower in the dietary intervention than the control group at the end of the trial. C-reactive protein (a measure of inflammation) and blood glucose levels were also lower in the intervention than in the control group. Blood lipid levels did not differ between the two groups. No differences were noted in infant birth weight.

Dietary supplementation with combined blueberries and soluble fiber beginning in the early stages of pregnancy may help to improve pregnancy outcomes particularly in obese women at increased risk for GDM. Although nutrition education was provided to both groups as part of standard prenatal care, food supplementation appeared to be more effective in improving maternal risks. These findings warrant investigation in larger trials to further address the role of bioactive-rich foods in reducing diabetes complications during pregnancy.  A corresponding editorial by Ana Rodriquez-Mateos (King’s College London) stresses the key importance o the implementation of specific dietary recommendations for women at risk of GDM, encouraging further studies to address this question.


Basu A, Feng D, Planinic P, Ebersole JL, Lyons TJ, Alexander JM.  Dietary Blueberry and Soluble Fiber Supplementation Reduces Risk of Gestational Diabetes in Women with Obesity in a Randomized Controlled Trial. The Journal of Nutrition, Volume 151, Issue 5, May 2021, Pages 1128–1138,

Rodriguez-Mateos A.  Can (poly)phenols lower the risk of gestational diabetes? The Journal of Nutrition, Volume 151, Issue 5, May 2021, Pages 1057–1058,

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