RESUMO
BACKGROUND: High-fat meal (HFM) consumption may induce transient postprandial atherogenic responses, including impairment of vascular endothelial function, in individuals with overweight/obesity. Red beetroot juice (RBJ) may modulate endothelial function and other measures of cardiometabolic health. OBJECTIVE: This study investigated the impact of acute and chronic RBJ consumption, including nitrate-dependent and -independent effects, on postprandial endothelial function and other cardiometabolic responses to a HFM. METHODS: Fifteen men and postmenopausal women with overweight/obesity were enrolled in this randomized, double-blind, placebo-controlled, 4-period, crossover clinical trial. Following an overnight fast, participants underwent baseline assessment of endothelial function (reactive hyperemia index; RHI) and hemodynamics, and biological sample collection. In random order, participants consumed 70 mL (acute visit) of: 1) RBJ, 2) nitrate-free RBJ (NF-RBJ), 3) placebo + nitrate (PBO + NIT), or 4) placebo (PBO), followed by a HFM. RHI was remeasured 4 h post-HFM, and hemodynamic assessment and biological sample collection were performed 1, 2, and 4 h post-HFM consumption. Participants consumed treatments daily for 4 wk (chronic visit), and assessments were repeated before/after the HFM (without consuming treatments). RESULTS: HFM consumption did not induce significant impairment of postprandial RHI. No significant differences in RHI were detected across treatment groups following acute or chronic exposure, despite increases in circulating nitrate/nitrite (NOx) concentrations in the RBJ and PBO + NIT groups compared with PBO and NF-RBJ (P < 0.0001 for all time points at the acute visit; P < 0.05 for all time points at the chronic visit). Although the HFM led to significant alterations in several secondary outcomes, there were no consistent treatment effects on postprandial cardiometabolic responses. CONCLUSIONS: HFM consumption did not impair postprandial endothelial function in this population, and RBJ exposure did not alter postprandial endothelial function or other outcomes despite increasing NOx concentrations. This trial is registered at clinicaltrials.gov as NCT02949115.
RESUMO
Previous research suggests potential for fresh pears as a functional food for promoting cardiometabolic health. The purpose of this randomized, open-label, placebo-controlled, crossover clinical trial was to evaluate the influence of daily fresh pear consumption on blood pressure (primary outcome) and other biomarkers of cardiometabolic health in middle-aged/older adults with metabolic syndrome (MetS). Forty men and women aged 45-65 years with MetS were included and randomly assigned to receive either two medium-sized fresh pears (Pear) or a calorie-matched control drink (Control) per day for each 12-week treatment period, each separated by a 4-week washout period. After 12 weeks of daily fresh pear consumption, systolic blood pressure tended to be reduced (130 ± 2 mmHg vs. 134 ± 2 mmHg at baseline, P = 0.07) and pulse pressure was significantly reduced (51 ± 1 vs. 54 ± 1 at baseline, P < 0.05). At 12 weeks, leptin concentrations were lower in the Pear group than Control (52.5 [7.6, 120.5] ng dL-1vs. 53.4 [5.0, 120.5] ng dL-1, respectively, P < 0.05), and there was a significant group by time interaction (P < 0.05). Leptin concentrations were significantly reduced at 12 weeks compared to baseline in the Pear group (52.5 [7.6, 120.5] ng dL-1vs. 54.8 [6.4, 120.5] ng dL-1 at baseline, P < 0.05) but not in the Control group. Waist circumference was significantly reduced at 12 weeks in the Pear group (107.7 ± 2.0 cm vs. 108.4 ± 2 cm at baseline, P < 0.05) with a trend for a group by time interaction (P < 0.1), and significantly lower in the Pear group than Control (108.1 ± 2.0 cm vs. 108.8 ± 2 cm, P < 0.05) at 6 weeks with a significant group by time interaction (P < 0.05). Conversely, values were significantly increased at 6 weeks (108.8 ± 2 cm vs. 108.3 ± 2.0 cm at baseline, P < 0.05) in the Control group and sustained at 12 weeks. Waist-to-hip ratio was significantly reduced (0.92 ± 0.01 vs. 0.93 ± 0.01 at baseline, P < 0.05) at 12 weeks in the Pear group, and significantly lower than Control at 6 weeks (0.93 ± 0.01 vs. 0.93 ± 0.01, respectively, P < 0.05) and 12 weeks (0.92 ± 0.01 vs. 0.93 ± 0.01, P < 0.05). These findings suggest that daily fresh pear consumption may promote modest improvements in cardiometabolic health in middle-aged/older adults with MetS. This trial was registered at clinicaltrials.gov as NCT02228837.
