Addition of Orange Pomace to Orange Juice Attenuates the Increases in Peak Glucose and Insulin Concentrations after Sequential Meal Ingestion in Men with Elevated Cardiometabolic Risk

Abstract

Background: Prospective cohort studies show that higher dietary fiber intake is associated with reduced cardiovascular disease risk, yet the impact on postprandial glucose and insulin responses is unclear.

Objective: This study aims to evaluate the effects of orange beverages with differing fiber concentrations on postprandial glycemic responses (secondary outcome measure) after a sequential breakfast and lunch challenge in men with increased cardiometabolic risk.

Methods: Thirty-six men (aged 30-65 y; body mass index 25-30 kg/m(2): fasting triacylglycerol or total cholesterol concentrations: 0.8-2.2 or 6.0-8.0 mmol/L, respectively) were provided with a high-fat mixed breakfast and were randomly assigned to consume 240 mL Tropicana (PepsiCo, Inc.) pure premium orange juice without pulp (OJ), OJ with 5.5 g added orange pomace fiber (OPF), juice made from lightly blended whole orange, or an isocaloric sugar-matched control (Control) on 4 occasions separated by 2 wk. A medium-fat mixed lunch was provided at 330 min. Blood samples were collected before breakfast and on 11 subsequent occasions for 420 min (3 time points postlunch) to determine postprandial glucose, insulin, lipid, and inflammatory biomarker responses. Repeated-measures ANOVA was used for data analysis.

Results: OPF significantly (P < 0.05) reduced the maximal change in glucose concentrations (1.9 ± 0.21 mmol/L) reached after breakfast compared with other treatments (2.3-2.4 mmol/L) and after lunch (3.0 ± 0.05 mmol/L) compared with OJ (3.6 ± 0.05 mmol/L). The maximal change in insulin concentration (313 ± 25 pmol/L) was also lower compared with Control (387 ± 30 pmol/L) and OJ (418 ± 39 pmol/L) after breakfast. OPF significantly delayed the time to reach the peak glucose concentration compared with Control and OJ, and of insulin compared with Control after breakfast.

Conclusion: OPF consumed with breakfast may lower postprandial glycemic and insulinemic responses to typical meal ingestion in men with increased cardiometabolic risk. This trial is registered at clinicaltrials.gov as NCT01963416.

Keywords: cardiometabolic risk; dietary fiber; high-fat meal challenge; orange juice; postprandial response.