Adults aged 50 to 70 years with prediabetes who ate one fresh mango daily for 24 weeks had lower fasting blood glucose at week 24 compared with adults assigned a calorie-matched granola bar. The between-group difference at week 24 was 18.3 mg/dL. Fasting glucose decreased to 107.0 mg/dL with mango and increased to 125.3 mg/dL with control. Hemoglobin A1c remained stable with mango but increased to 5.9 ± 0.1% with control. Insulin sensitivity was higher with mango at week 24, and insulin resistance was lower vs. control. Body composition favored mango: body fat percentage trended lower by week 12, fat-free mass increased by week 24, and waist-to-hip ratio decreased by week 12; controls showed an increase in waist-to-hip ratio over time. The differences in fasting blood glucose, HbA1c, insulin sensitivity, fat-free mass, and waist-to-hip ratio between groups were statistically significant.
Researchers randomized 24 patients; 23 completed the trial (mango: n = 11; control: n = 12). Eligibility included fasting plasma glucose 100 to 125 mg/dL or hemoglobin A1c 5.7 to 6.4% and body mass index 18.5 to 34.9 kg/m²; women were postmenopausal. Patients assigned to the mango group consumed an average fresh Tommy Atkins mango daily (about 300 g edible portion; approximately 195 kcal; 5.4 g fiber). The comparator was a calorie-matched granola bar (about 190 kcal; about 2 g fiber; about 140 mg sodium). The mango portion contained 32.1 g total sugars (natural), and the granola bar contained 11 g added sugar. Outcomes were measured at baseline and weeks 6, 12, and 24; compliance was defined as at least 80% and p-values of less than 0.05 were considered statistically significant. Baseline distributions of sex, race, and ethnicity differed between groups and were included as covariates in relevant models.
“We selected the bar to (1) reflect a typical snack in free-living settings, (2) standardize composition to improve feasibility and adherence, and (3) provide a calorie-matched comparator with lower fruit-specific bioactive content, allowing evaluation of mango’s whole-fruit matrix effects beyond energy and sugar content alone,” wrote lead study author Raedeh Basiri, PhD, of George Mason University, and colleagues. They also noted, “Excluding frequent consumers helped standardize exposure and improve internal validity.”
Limitations included a small sample with limited diversity; baseline imbalances in sex, race, and ethnicity with potential residual confounding despite covariate adjustment; and the absence of objective dietary biomarkers. Only fasting glucose was powered as the primary outcome; other endpoints were exploratory without multiplicity adjustment.
Despite containing more intrinsic sugars than the isocaloric granola-bar comparator (≈32.1 g vs. 11 g), the researchers wrote that mango “produced more favorable glycemic indices and body composition changes.” This is important, they noted, because it aligns with previous research and hypotheses that greater muscle mass is protective while excess adiposity may contribute to risk of type 2 diabetes.
The researchers wrote: “A major strength of our study is its 24-week duration, which enabled us to evaluate both short- and longer-term effects of fresh mango consumption.” The paper also placed the results in the prevention context, noting that “In the Diabetes Prevention Program, lifestyle intervention reduced the incidence of type 2 diabetes by 58%, whereas metformin reduced it by 31% compared with placebo.” Looking ahead, the researchers wrote, “Future studies should incorporate objective dietary biomarkers (e.g., plasma carotenoids, urinary polyphenols) to improve their accuracy and validity,” and “future studies should explore the broader health benefits of mango consumption beyond glycemic control and body composition, including potential metabolic pathway effects and gene expression changes, given that individuals may respond differently to the same foods.”
The National Mango Board funded the study. The researchers reported no conflicts of interest; the funders had no role in study design, data collection, analysis, or interpretation.
Source: Foods
