Gestational diabetes mellitus (GDM), defined as abnormal glucose tolerance that presents during the second and third trimesters of pregnancy, is a growing issue in the United States and worldwide. If left untreated or poorly controlled, GDM can result in numerous consequences for both the mother and the fetus; thus, it is imperative that different avenues of management for GDM be explored. There is a paucity of studies that examine how lifestyle changes, including dietary and physical activity, affect management of GDM. We examined how counseling on lifestyle changes can affect cardiometabolic risks in women with GDM. We conducted a 12-week randomized controlled trial based on behavioral counseling in which women with GDM (N = 38) were randomized into either a nutrition education (control) (N = 18) group or nutrition intervention (N = 20) group. The nutrition education group were given dietary counseling regarding healthy dietary choices based on USDA guidelines, while the nutrition intervention group were instructed to consume a total of one cup of whole berries and one cup of leafy vegetables daily along with performing postprandial exercise (walking). Blood samples, anthropometric measures, and dietary and physical activity data, recorded in daily food and activity logs, were collected at baseline and at the end of the study and compared between the two groups. Dietary counseling on supplementation with whole berries and leafy vegetables resulted in increased fiber intake, increased antioxidant intake and total serum antioxidant capacity, improved random blood glucose, decreased serum IL-6, and improved HDL cholesterol versus the control group (all p < 0.05). These results highlight that whole berry and leafy vegetable supplementation-based dietary counseling can improve the metabolic pathways involved in gestational diabetes pathogenesis and prognosis. These functional foods must be recommended in the management of pregnancies affected by GDM.

Gestational diabetes mellitus (GDM) is defined as glucose intolerance identified during pregnancy. The increased risk of pregnancy complications and the adverse health effects for the mother and baby associated with GDM require urgent and effective ways to control the condition. The primary goal of this semi-quantitative review was to examine the effects of phytochemicals and plant-based diets on GDM in clinical studies involving women undergoing pregnancy and to summarize the findings for application in clinical practice and disease management. The articles included in this review show that intervention strategies, including fruits, vegetables, whole grains, nuts and seeds, and tea, may be beneficial in the management of GDM and lower blood glucose and improve adverse pregnancy outcomes in these women. The randomized controlled trials reviewed collectively show improved glycemic control markers, blood lipid values, and body weight and composition when supplemented with phytochemical-rich supplements and foods compared to those in the control groups. The findings support the clinical observations of lower GDM risks in women consuming plant-derived diets rich in phytochemicals. Nutrition interventions involving plant-based foods and diets are thus a practical way to reduce hyperglycemia both in patients diagnosed with GDM and those at high risk for the development of GDM.

Prediabetes increases oxidative stress and the risk of type 2 diabetes and related cardiovascular diseases. Previous trials have shown antioxidant-rich strawberries improve this risk, but effects on antioxidant markers are inconclusive. This 28-week randomized controlled crossover trial evaluated the effects of freeze-dried strawberries (FDS) on fasting glucose, serum antioxidant status, and vascular inflammation in adults with prediabetes not on glucose-lowering medications. Participants were assigned to FDS (32 g/day ~ 2.5 servings of whole strawberries) or control (usual diet, no strawberries) for 12 weeks each, separated by a 4-week washout (n = 25/treatment period). Biomarkers were measured at baseline, 12, 16 (baseline 2), and 28 weeks. A mixed-model analysis of variance detected differences between groups, adjusting for covariates. Compared to control, FDS significantly improved serum superoxide dismutase (0.08 ± 0.04 U/mL), glutathione [(GSH): 1.8 ± 0.96 µmol/L], antioxidant capacity [(AC): 5.9 ± 3.2 µmol/L], β-carotene (113.9 ± 15.8 nmol/L), fasting glucose (97 ± 12 mg/dL), intercellular adhesion molecule [(ICAM): 56.0 ± 21.8 ng/mL], and vascular cell adhesion molecule [(VCAM): 440 ± 163 ng/mL] (all p < 0.05). ICAM was inversely correlated with GSH (r = −0.21), AC (r = −0.15), and β-carotene (r = −0.13) (all p < 0.05). VCAM was inversely correlated with AC (r = −0.12) (p < 0.05). Catalase, glutathione reductase, glutathione peroxidase, α-carotene, P-selectin, and E-selectin were unaffected. Our findings support strawberry intake as a dietary intervention for improving blood glucose control and antioxidant status in adults with prediabetes.