(P04-028-24) Dose-Related Effects of Strawberry Intake on Endothelial Function and Glucose Control

Objectives: The study aimed to investigate dose-related effects of strawberry fruit intake on endothelial function and glucose control, and the relationship of flow-mediated dilation (FMD) responses to intervention to cardiovascular disease risk (CVD).

Methods: In this randomized, 3-arm parallel, controlled study, 68 adult non-smokers with chronic low-grade inflammation were recruited to ingest freeze-dried strawberry as frozen smoothie (41 g) at two dose levels: high-dose (36 g), low-dose (12g) strawberries vs. control (0 g) for 4 weeks. FMD% was measured using ultrasound measuring the change in brachial artery diameter in response to blood flow (sheer stress) stimulus pre and post intervention. Continuous-glucose-monitors (CGM) were worn for up to 8 days twice during the study to monitor daily glucose excursions. Non-parametric tests were used to test for significant effects of intervention on FMD and CGM and Multiple Logistic Regression model was used to determine the CVD risk by explanatory variables with adjusted coefficients. Missing data were iterated with multiple imputation.

Results: Thirty-six women and 32 men, 33±6 y (20 to 62 years) and body mass index (BMI) 29.8±4.8 kg/m² completed the study. Baseline measurements of age, sex, ethnicity, BMI, systolic blood pressure, and fasting blood sugar showed no significant difference across the interventions. FMD% was significantly influenced by the strawberry treatments of high-dose, low-dose, and control towards higher to lower median, respectively (Kruskal-Wallis test, p< 0.001). Preliminary analyses of CGM suggest no significant differences between interventions in changes from baseline (Kruskal-Wallis test p >0.05). In a logistic regression model using all interventions with FMD responses and a 2% increase in FMD as an indicator of reduced CVD risk, our modeling (with goodness of fit p=0.33) suggested strawberry intake dose-dependently reduced CVD risk by 8-times compared to the control group (p < 0.001). The sensitivity analysis, in which missing primary outcome data were imputed, resulted in similar findings (odd ratio, 8.029; to 7.029; p< 0.001 to p=0.002).

Conclusions: The present study demonstrated improvements in FMD% with strawberry intake towards lowering CVD risk.

Funding Sources: California Strawberry Commission