Acute and long term effects of grape and pomegranate juice consumption on endothelial dysfunction in pediatric metabolic syndrome

BACKGROUND: This study aimed to determine the short- and long-term effects of consumption of grape and pomegranate juices on markers of endothelial function and inflammation in adolescents with metabolic syndrome (MetS). METHODS: In a non-pharmacologic randomized controlled trial, 30 individuals were randomly assigned to two groups of drinking natural grape or pomegranate juice for 1 month. Measurements of inflammatory factors [Hs-CRP, sEselectin, sICAM-1, sVCAM, and interleukin 6 (IL-6)] and flow-mediated dilation (FMD) were made at baseline, 4 hours after first juice consumption and after one month of juice consumption. RESULTS: The percent changes of FMD were significant in both groups in the short- and long-term. Hs-CRP had a nonsignificant decrease. sE selectin had a significant decrease after 4 hours in total and in the pomegranate juice group, followed by a significant decrease after 1 month in both groups. After 4 hours, sICAM-1 significantly decreased in the pomegranate juice group, and after 1 month it decreased in total and pomegranate juice group. Interleulkin-6 (IL-6) had a significant constant decrease at 4-hour and 1-month measurements after drinking pomegranate juice, and in both groups after 1 month. Significant negative correlations of changes in sICAM-1 and sE-selectin with changes in FMD were found in both periods of follow-up; and at 1 month for IL-6. CONCLUSIONS: Decline in inflammation was associated with improvement in FMD without changes in conventional risk factors. Daily consumption of natural antioxidants may improve endothelial function in adolescents with MetS.