8 weeks supplementation of fruit and vegetable juice concentrate reduced postprandial inflammation in overweight/obese, but otherwise healthy, women

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Purpose: The prevalence of overweight/obesity is growing not only in the United States, but also worldwide. Increased adiposity is associated with systemic, chronic inflammation, which links obesity to the various chronic diseases that are secondary to overweight/obesity. Dietary antioxidants from fruits and vegetables have been shown to reduce the systemic inflammation in overweight/obese individuals. Therefore, the objective of the present study was to 1) investigate if 8 weeks supplementation of fruit and vegetable juice concentrate (FVJC) lowered markers of oxidative stress and systemic inflammation in overweight/obese women, and 2) if 8 weeks supplementation of FVJC lowered postprandial inflammatory response induced by a high-fat, high-carbohydrate (HFHC) meal. Methods: 16 overweight/obese, but otherwise healthy women, aged between 18-45 years old, participated in this placebo-controlled, randomized study. They were randomized into the FVJC supplementation group (FVJC, n=9) and the placebo group (Placebo, n=7). They underwent a HFHC meal test before and at the end of the corresponding treatment of either FVJC or placebo. Fasting blood sample and additional blood samples at 1 hour, 2 hours, 4 hours and 6 hours after the HFHC meal ingestion were collected. Oxidative stress marker (protein carbonyl), cytokines (interlukin-6, IL-6; Tumor necrosis factor-?, TNF-?; IL-1? and monocyte chemoattractant protein-1, MCP-1) and adipokines (adiponectin; leptin; resistin; total plasminogen activator inhibitor-1, total PAI-1 and lipocalin) were measured in fasting blood samples; glucose, triglycerides, and insulin, as well as cytokines are measured both in the fasting and postprandial blood samples. A two-way (time, group) repeated measures ANOVA was used to compare if there was any difference in fasting adipokines and cytokines at pre- and post-treatment within each group; a one-way (time) repeated measures ANOVA was used to compare if postprandial glucose, triglycerides, insulin and cytokines changed significantly after the HFHC meal. Peak concentrations, defined as the highest concentrations among the postprandial measurements, was compared with the corresponding fasting concentrations with paired t-test for glucose, triglycerides, insulin and cytokines. Incremental area under curve (iAUC) was calculated for glucose, triglycerides, insulin, and cytokines, and a two-way (time, group) repeated measures ANOVA was used to compare if post-treatment iAUC and peak concentrations changed significantly from pre-treatment in two groups. Post-hoc t-test was performed if there was any significant main or interaction effect for time and group. Significance level was defined as p<0.05. Results: There was no significant change of fasting cytokines and adipokines in either the FVJC group or the placebo group. Postprandial peak glucose, triglycerides, insulin and cytokines were significantly higher than the corresponding fasting concentrations. Peak concentrations of glucose, triglycerides, insulin and cytokines were unchanged in both groups after 8 weeks; iAUC of IL-6 was lowered insignificantly in the FVJC group, but increased in the placebo group; and iAUC of TNF-? was significantly lowered in the FVJC group, while unchanged in the placebo group. Conclusions: Overweight/obese healthy women did not have elevated fasting or basal markers of oxidative stress or systemic inflammation, and 8 weeks supplementation of FVJC did not alter fasting concentrations of oxidative stress or systemic inflammation markers. However, 8 weeks of FVJC supplementation significantly lowered postprandial inflammatory response triggered by a HFHC meal.