(P26-026-25) Freeze-Dried Strawberries Improve Insulin Resistance and Glycemic Control in Adults With Prediabetes: A Randomized Controlled Crossover Trial

Objectives: Prediabetes is a risk factor for developing type 2 diabetes and cardiovascular disease (CVD), with inflammation and impaired glucose metabolism as substantial contributing factors. This study evaluated effects of strawberries as a rich source of bioactive compounds on inflammatory biomarkers, CVD risk factors, and insulin resistance in adults with prediabetes.

Methods: A randomized controlled crossover trial was conducted in adults with prediabetes (n=25), who were assigned to either a “strawberry” (32 g freeze-dried powder/day) or “no strawberry” phase each for 12 weeks, separated by a 4-week washout. Serum blood lipids, glycemic variables (glucose, HbA1c, HOMA-IR) and biomarkers of inflammation (CRP, adiponectin, IL-6, TNF-α) were measured at baseline, six, 12, 16, 22, and 28 weeks. Anthropometrics and blood pressure (BP) were also evaluated. Mixed-model ANOVA was used to detect differences between phases.

Results: After adjusting for time, order of randomization, age, ethnicity, sex, dietary calories and physical activity over 12 weeks, and baseline value for each outcome, the strawberry phase significantly improved the following outcomes (adjusted mean differences (95% CIs)): fasting glucose -8.9 (-4.7, -13.2) mg/dL, insulin -6.9 (-3.2, -10.7) µIU/mL, HOMA-IR -2.3 (-1.3, -3.4), HbA1c -0.2 (-0.1, -0.3) %, total cholesterol -7.0 (-2.0, -12.0) mg/dL, hs-CRP -0.8 (-0.3, -1.3) mg/L, IL-6 -10.8 (-7.8, -13.7) ng/mL, body weight -3.4 (-1.9, -4.8) lb, and waist circumference -0.4 (-0.2, -0.7) inches (all p< 0.05). Adjusted mean difference for systolic BP was significantly lower post-strawberry phase. No significant differences were noted in serum LDL-, HDL-cholesterol, triglycerides, TNF-α, adiponectin, and catalase.

Conclusions: Freeze-dried strawberry supplementation showed significant improvements in insulin resistance, CVD biomarkers, and inflammation in adults with prediabetes. These data support consumption of strawberries as a beneficial dietary intervention to help mitigate disease progression in prediabetes.

Funding Sources: California Strawberry Commission, Watsonville, CA
National Institute of General Medical Sciences (U54 GM104944)