Effect of fruit and vegetable concentrates on endothelial function in persons with metabolic syndrome: A randomized, controlled, crossover trial

Abstract

Dehydrated fruit and vegetable concentrates provide an accessible form of phytonutrient supplementation that may offer cardioprotective effects. This study assessed the effects of encapsulated fruit and vegetable juice powder concentrates on endothelial function (EF) and cardiac risk markers in subjects with metabolic syndrome (MS) in a randomized, double blind, placebo controlled crossover trial. 64 adults with MS were enrolled and received 8‐week sequences of two different blends of the concentrates and placebo. The primary outcome measure was change in EF 2hr after consuming a 75g glucose load, after 8‐weeks of daily consumption or 2hr after consumption of a single dose. Secondary outcome measures included plasma glucose, serum insulin, serum lipids, and weight. A single dose of fruit, vegetable, and berry mixtures appeared to preserve EF (p=0.0549). There were, however, no significant between group differences in EF with daily treatment for 8 weeks. No other significant treatment effects were discerned in glucose, insulin, lipids, and weight. Daily supplementation with fruit and vegetable concentrates did not improve EF or other cardiac risk measures in this population of adults with MS in whom baseline EF was fairly normal. A blend of fruit, vegetable, and berry mixtures appeared to mitigate adverse effects of an acute glucose load on EF, a finding which warrants further investigation.