RATIONALE:

A primary goal of therapy for patients with peripheral artery disease (PAD) and intermittent claudication is increased ambulatory function. Supervised exercise rehabilitation was recently shown to confer superior walking benefits to pharmacological or surgical interventions. Increases in plasma inorganic nitrite, via oral nitrate, have been shown to increase exercise performance in both human and animal models, especially in hypoxic conditions.

OBJECTIVE:

To determine whether a 36-session exercise rehabilitation program while consuming oral inorganic nitrate (4.2 mmol concentrated beetroot juice) would produce superior benefits over exercise plus placebo in pain-free walking and markers of increased skeletal muscle perfusion in patients with PAD and intermittent claudication.

METHODS AND RESULTS:

This was a randomized, double-blind, per-protocol study design. After the 12-week protocol, claudication onset time on a maximal treadmill test increased by 59.2±57.3 s for the exercise plus placebo group (n=13) and by 180.3±46.6 s for the exercise plus beetroot juice group (n=11; P≤0.05). This produced a between treatment medium to large standardized effect size (Cohen d) of 0.62 (95% CI, -0.23 to +1.44). The data for 6-minute walk distance showed a similar pattern with increases of 24.6±12.1 and 53.3±19.6 m ( P≤0.05) in the exercise plus placebo and exercise plus beetroot juice groups, respectively. Measures of gastrocnemius perfusion, including ankle-brachial index, peak reactive hyperemic blood flow, and tissue deoxygenation characteristics, during exercise (assessed my near-infrared spectroscopy) all changed significantly for the exercise plus beetroot juice group with moderate-to-large effect sizes over exercise plus placebo changes.

CONCLUSIONS:

Although it is premature to speculate on overall clinical utility of a nitrate-based therapy for PAD, this early pilot study evidence is encouraging. Specifically, our data suggests that increasing plasma nitrite before exercise may allow PAD subjects to train with less pain, at higher workloads for longer durations at each training session, thereby maximizing the beneficial peripheral vascular and skeletal muscle adaptations.

CLINICAL TRIAL REGISTRATION:

URL:

http://www.clinicaltrials.gov . Unique identifier: NCT01684930 and NCT01785524.

Six days of dietary nitrate supplementation in the form of beetroot juice (~0.5 L/d) has been reported to reduce pulmonary oxygen uptake (VO₂) during submaximal exercise and increase tolerance of high-intensity work rates, suggesting that nitrate can be a potent ergogenic aid. Limited data are available regarding the effect of nitrate ingestion on athletic performance, and no study has investigated the potential ergogenic effects of a small-volume, concentrated dose of beetroot juice. The authors tested the hypothesis that 6 d of nitrate ingestion would improve time-trial performance in trained cyclists. Using a double-blind, repeated-measures crossover design, 12 male cyclists (31 ± 3 yr, VO_2peak = 58 ± 2 ml · kg^-1 · min-^-1, maximal power [W_max] = 342 ± 10 W) ingested 140 ml/d of concentrated beetroot (~8 mmol/d nitrate) juice (BEET) or a placebo (nitrate-depleted beetroot juice; PLAC) for 6 d, separated by a 14-d washout. After supplementation on Day 6, subjects performed 60 min of submaximal cycling (2 × 30 min at 45% and 65% W_max, respectively), followed by a 10-km time trial. Time-trial performance (953 ± 18 vs. 965 ± 18 s, p < .005) and power output (294 ± 12 vs. 288 ± 12 W, p < .05) improved after BEET compared with PLAC supplementation. Submaximal VO₂ was lower after BEET (45% W_max = 1.92 ± 0.06 vs. 2.02 ± 0.09 L/min, 65% W_max 2.94 ± 0.12 vs. 3.11 ± 0.12 L/min) than with PLAC (main effect, p < .05). Wholebody fuel selection and plasma lactate, glucose, and insulin concentrations did not differ between treatments. Six days of nitrate supplementation reduced VO₂ during submaximal exercise and improved time-trial performance in trained cyclists.

OBJECTIVE:

The purpose of this study is to comparatively evaluate the effect of discoloration of nanohybrid composite by four different phytopigments.

MATERIALS AND METHODS:

Fifty disk-shaped samples of nanohybrid (3M Filtek Z350) resin composites were prepared using an acrylic template of dimension 5 mm × 3 mm. They were randomly divided into five groups and immersed in solutions of tomato powder, beetroot powder, java plum powder, and turmeric powder. Distilled water was used as the control group. The samples were placed in respective solutions for 3 h daily and stored in artificial saliva for the rest of the day for 28 days. Color values (L*, a*, b*) were measured by colorimeter using the CIE L*a*b* system at the end of the 7th and 28th days of immersion. Color differences ΔE*ab were statistically analyzed.

RESULTS:

All the samples showed a change in color of nanohybrid composite resin to varying degrees. The mean ΔE*ab value obtained with beetroot solution was the highest among all the groups at the end of the 7th and 28th days, depicting that beetroot solution showed maximum mean color variation, followed by java plum solution, turmeric solution, and tomato solution.

CONCLUSION:

All the phytopigments used in this study have the potential to discolor the nanohybrid composite resin, with beetroot causing the most severe discoloration.

Acute consumption of dietary nitrate (as beetroot juice) has been shown to improve exercise capacity in athletes, healthy adults and subjects with both peripheral vascular disease or COPD. Many patients with dilated cardiomyopathy have reduced exercise capacity, The investigators hypothesized that acute nitrate consumption might increase incremental shuttle walk test (ISWT) distance in dilated cardiomyopathy subjects compared to a placebo beetroot juice.

Emerging evidence suggests that increasing dietary nitrate intake may be an effective approach to reduce blood pressure. Beetroot juice is often used to supplement dietary nitrate, whereas nitrate intake levels from habitual diet are low. An increase in the habitual intake of nitrate-rich vegetables may represent an alternative to nitrate supplementation. However, the effectiveness and acceptability of a nitrate–rich-vegetables diet remain to be established. The aim was to investigate the effect and feasibility of two different intervention strategies to increase dietary nitrate intake, on plasma nitrate/nitrite concentrations and blood pressure. A randomized, crossover trial was used. Participants were healthy men and women (both n=15; age: 24±6 years) from the Netherlands. Participants were instructed to consume ∼400 mg nitrate at lunch, provided through nitrate-rich vegetables and dietary counseling, or beetroot juice supplementation. Both interventions lasted 1 week, with 1-week washout (January to April 2017). Plasma nitrate and nitrite concentrations and resting systolic and diastolic blood pressure were measured in an overnight fasted state (before and after intervention) and ∼2.5 hours after lunch (before and throughout intervention on day 1, 4, and 7). Two-factor (time × treatment) repeated-measures analyses of variance were performed. Mean plasma nitrate concentrations increased with both interventions, with a larger increase in beetroot juice vs nitrate-rich vegetables, both in a fasted state and ∼2.5 hours after lunch (day 1, beetroot juice: 2.31±0.56 mg/dL [373±90 μmol/L] vs nitrate-rich vegetables: 1.71±0.83 mg/dL [277±134 μmol/L]; P <0.001). Likewise, mean plasma nitrite concentrations increased with both interventions, but were higher after lunch in beetroot juice than in nitrate-rich vegetables (day 1: 2.58±1.52 μg/dL [560±331 nmol/L] vs 2.15±1.21 μg/dL [468±263 nmol/L]; P =0.020). Fasting mean systolic and diastolic blood pressure did not change, but mean systolic and diastolic blood pressure assessed ∼2.5 hours after lunch were significantly reduced throughout both intervention periods (P <0.05), with no differences between beetroot juice and nitrate-rich vegetables (day 1, systolic blood pressure: –5.1±9.5 mm Hg and diastolic blood pressure: –5.3±8.9 mm Hg). Short-term consumption of dietary nitrate in the form of nitrate-rich vegetables represents an effective means to increase plasma nitrate and nitrite concentrations, and reduces blood pressure to the same extent as beetroot juice supplementation.

Objectives: Cardiovascular disease (CVD) is the leading cause of death in women, with the risk being greater following menopause. Consumption of beetroot juice and other nitraterich foods is a promising non‐pharmacological strategy for increasing systemic nitric oxide to improve endothelial function in elderly populations. The purpose of this randomized, placebo‐controlled, crossover clinical trial was to determine if short‐term dietary nitrate supplementation, in the form of beetroot juice, could improve baseline endothelial function in postmenopausal women at two distinct stages of menopause. Methods: Early‐ (1–6 years following their final menstrual period (FMP), n=12) and late‐ (>6 years FMP, n=12) postmenopausal women consumed nitrate‐rich (300 mg/70mL) and nitrate‐depleted beetroot juice (0 mg/70 mL, placebo) for 7 days. Brachial artery flow mediated dilation (FMD)was measured pre‐ and post‐7‐day supplementation. Results: Analyses with general linear models (SPSS) revealed a significant (p<0.05) treatment*time interaction (p=0.047) for baseline FMD (FMDnitrate=4.43±2.80% and FMDplacebo=5.27±2.37%) and post‐supplementation FMD (FMDnitrate=6.47±2.52% and FMDplacebo=5.09±3.01%). Stratification of postmenopausal women into early‐ and lategroups revealed no significant interaction effect. Conclusions: These results suggest that 7 days of nitrate‐rich (300 mg/70 mL) beetroot juice supplementation is sufficient to increase resting endothelial function to a similar extent in postmenopausal women at both postmenopausal stages. Funding Sources: T32DK120509, T32GM108563, UL1 TR002014.

Nitric oxide alters gastric blood flow, improves vascular function, and mediates glucose uptake within the intestines and skeletal muscle. Dietary nitrate, acting as a source of nitric oxide, appears to be a potential low-cost therapy that may help maintain glucose homeostasis. In a randomized, double-blind, placebo-controlled crossover study, 31 young and older adult participants had a standardized breakfast, supplemented with either nitrate-rich beetroot juice (11.91 mmol nitrate) or nitrate-depleted beetroot juice as placebo (0.01 mmol nitrate). MRI was used to assess apparent diffusion coefficient (ADC), portal vein flux, and velocity. Plasma glucose, incretin, and C-peptide concentrations and blood pressure were assessed. Outcome variables were measured at baseline and hourly for 3 h. Compared with a placebo, beetroot juice resulted in a significant elevation in plasma nitrate and plasma nitrite concentration. No differences were seen for the young or older adult cohorts between placebo and beetroot juice for ADC, or portal vein flux. There was an interaction effect in the young adults between visits for portal vein velocity. Nitrate supplementation did not reduce plasma glucose, active GLP-1, total GLP-1, or plasma C-peptide concentrations for the young or older adult cohorts. Despite a significant elevation in plasma nitrite concentration following an acute dose of (11.91 mmol) nitrate, there was no effect on hepatic blood flow, plasma glucose, C-peptide, or incretin concentration in healthy adults.

Introduction: Beetroot juice is a naturally rich source of nitrate (NO3-), a compound hypothesized to enhance endurance performance by improving exercise efficiency. This study investigated the effect of multiple doses of beetroot juice on 2000m ergometer rowing performance in well trained athletes. Methods: Ten highly trained male rowers (17±3.4 h training per week) volunteered to participate in a counterbalanced, placebo controlled, cross-over study. Subjects were given either 0mmol (PLACEBO), 4.2mmol (SINGLE) or 8.4mmol (DOUBLE) NO3- via a beetroot juice supplement 2 h before undertaking a 2000mtest on a rowing ergometer. Blood samples were taken before supplement ingestion and immediately before the rowing test for later analysis of plasma [NO3-] and [nitrite (NO2-)]. Results: The SINGLE dose demonstrated a trivial effect compared to PLACEBO on 2000m time to completion. A possibly beneficial effect of DOUBLE was found compared to SINGLE (mean difference: -1.8±2.1 s) and PLACEBO (-1.6±1.6 s) respectively. Plasma [NO2-] and [NO3-] demonstrated a dose-response effect, with greater amounts of nitrate ingested leading to substantially higher concentrations (DOUBLE > SINGLE > PLACEBO). There was a moderate but insignificant positive correlation (r = 0.573, p = 0.065) between change in plasma [NO2-] and improvement in performance. Conclusion: When compared with placebo, a high (8.4mmol NO3-) but not moderate (4.2mmol NO3-) dose of beetroot juice 2 h before exercise improved 2000mrowing performance in highly trained athletes.

Objective: To investigate whether an acute intake of Beetroot Juice (BJ) improved performance factors in a repeated swimming effort at maximum speed in elite swimmers.

Methods: A total of 13 elite swimmers (6 girls and 7 boys) participated in this randomised, double-blind study. In 2 different trials, the swimmers ingested an injection of Beet-It (70 ml placebo (PL) or an injection of Beet-It 70 ml beetroot juice (BJ)) 3 hours before undergoing a 6x100m crawl intermittent maximal speed performance test.

The objective of this study was to determine the chronic effects of beetroot juice supplementation on the acute (90-minute post nitrate consumption) efficacy of converting dietary nitrate to plasma nitrate and plasma nitrite in healthy middle-to-older aged adults. the investigators were also interested in determining the effect of this intervention on fasting levels of plasma nitrate and nitrite over time. Furthermore, the number of participants classified as \"non-responders\" was determined based on increases in plasma nitrite achieved using tolerable volumes of beetroot juice by other studies.