Effects of acute dietary nitrate supplementation on cold-induced vasodilation in healthy males

2021 ◽  
Author(s):  
K. A. Wickham ◽  
S. W. Steele ◽  
S. S. Cheung
Keyword(s):  
Dietary Nitrate ◽  
Nitrate Supplementation ◽  
Healthy Males

scholarly journals Effect of acute dietary nitrate supplementation on sympathetic vasoconstriction at rest and during exercise

2019 ◽  
Vol 127 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Christopher J. de Vries ◽  
Darren S. DeLorey
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Skeletal Muscle ◽  
Beetroot Juice ◽  
Total Plasma ◽  
Dietary Nitrate ◽  
Arterial Blood ◽  
Sympathetic Vasoconstriction ◽  
Nitrate Supplementation ◽  
Healthy Males

Dietary nitrate ([Formula: see text]) supplementation has been shown to reduce resting blood pressure. However, the mechanism responsible for the reduction in blood pressure has not been identified. Dietary [Formula: see text] supplementation may increase nitric oxide (NO) bioavailability, and NO has been shown to inhibit sympathetic vasoconstriction in resting and contracting skeletal muscle. Therefore, the purpose of this study was to investigate the hypothesis that acute dietary [Formula: see text] supplementation would attenuate sympathetic vasoconstrictor responsiveness at rest and during exercise. In a double-blind randomized crossover design, 12 men (23 ± 5 yr) performed a cold-pressor test (CPT) at rest and during moderate- and heavy-intensity alternate-leg knee-extension exercise after consumption of [Formula: see text] rich beetroot juice (~12.9 mmol [Formula: see text]) or a [Formula: see text]-depleted placebo (~0.13 mmol [Formula: see text]). Venous blood was sampled before and 2.5 h after the consumption of beetroot juice for the measurement of total plasma nitrite/[Formula: see text] [NOx]. Beat-by-beat blood pressure was measured by Finometer. Leg blood flow was measured at the femoral artery via Doppler ultrasound, and leg vascular conductance (LVC) was calculated. Sympathetic vasoconstrictor responsiveness was calculated as the percentage decrease in LVC in response to the CPT. Total plasma [NOx] was greater ( P < 0.001) in the [Formula: see text] (285 ± 120 µM) compared with the placebo (65 ± 30 µM) condition. However, mean arterial blood pressure and plasma catecholamines were not different ( P > 0.05) between [Formula: see text] and placebo conditions at rest or during moderate- and heavy-intensity exercise. Sympathetic vasoconstrictor responsiveness (Δ% LVC) was not different ( P > 0.05) between [Formula: see text] and placebo conditions at rest ([Formula: see text]: −33 ± 10%; placebo: −35 ± 11%) or during moderate ([Formula: see text]: −18 ± 8%; placebo: −20 ± 10%)- and heavy ([Formula: see text]: −12 ± 8%; placebo: −11 ± 9%)-intensity exercise. These data demonstrate that acute dietary [Formula: see text] supplementation does not alter sympathetic vasoconstrictor responsiveness at rest or during exercise in young healthy males. NEW & NOTEWORTHY Dietary nitrate may increase nitric oxide bioavailability, and nitric oxide has been shown to attenuate sympathetic vasoconstriction in resting and contracting skeletal muscle and enhance functional sympatholysis. However, the effect of dietary nitrate on sympathetic vasoconstrictor responsiveness is unknown. Acute dietary nitrate supplementation did not alter blood pressure or sympathetic vasoconstrictor responsiveness at rest or during exercise in young healthy males.

Abstract P242: Dietary Nitrate Does not Reduce Resting Metabolic Rate or Oxidative Stress in Healthy Males

Circulation ◽  
2018 ◽  
Vol 137 (suppl_1) ◽  
Author(s):  
Haley M Fair ◽  
Caleb D Harrison ◽  
Evan J Bockover ◽  
Brycen J Ratcliffe ◽  
Sierra Crowe ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Dietary Nitrate ◽  
Young Males ◽  
Nitrate Supplementation ◽  
No Bioavailability ◽  
Plasma Nitrite ◽  
Healthy Males

Introduction: Nitric oxide (NO) is a vasodilator that increases blood flow by promoting relaxation of endothelium. Dietary nitrate supplementation increases plasma nitrite, a marker of overall NO bioavailability. Previously, acute dietary nitrate supplementation has been shown to reduce oxygen consumption and improve tolerance during submaximal exercise in healthy populations. Less is known about the effect of dietary nitrate on oxygen consumption at rest. Hypothesis: We hypothesized that dietary nitrate supplementation would reduce resting metabolic rate (RMR) and oxidative stress (8-isoprostane) at rest, via enhanced NO bioavailability via the oxygen independent Nitrate-Nitrite-Nitric Oxide pathway in healthy, young males. Methods: In a randomized, double-blind, cross-over study, ten healthy, young males (21 ± 2 years) visited the laboratory on 5 separate occasions. Participants completed informed consent paperwork and underwent protocol familiarization during visit 1. Prior to visits 2 and 4, participants fasted for 12 hours and adhered to an NIH-approved low-nitrate diet for 48 hours. During visits 2 and 4, an initial blood draw was performed to analyze baseline plasma nitrite and 8-isoprostane. Participants then completed a 30-minute resting metabolic rate (RMR) test. Two hours prior to visits 3 and 5, participants consumed either a placebo or dietary nitrate supplement (negligible and 6.2 mmol nitrate, respectively). During visits 3 and 5, participants also had blood drawn for analysis of the previously stated measurements, and completed an RMR test. Visits 2 and 3 were on consecutive days, followed by a week-long washout period between visit 3 and visit 4, while visit 4 and 5 also occurred on consecutive days. Results: Plasma nitrite significantly increased following dietary nitrate consumption compared to baseline values (27.56 ± 7.58 and 1.25 ± 1.51 arbitrary units, respectively). No difference was present between nitrate and baseline measurements for 8-isoprostane (155.75 ± 57.01 and 198.42 ± 66.44 pg/mL, respectively; p=0.55) and RMR (2086.60 ± 202.23 and 2050.00 ± 209.23 kcal/day, respectively; p=0.13). Conclusion: Dietary nitrate supplementation increases plasma nitrite, but does not change resting metabolic rate following an acute dose of dietary nitrate in healthy males. Individuals consuming dietary nitrate as an ergogenic aid during exercise may not, however, experience similar changes in their resting metabolism. The lack of change in oxidative stress may have been associated with the overall health of the cohort examined. Future research should investigate the clinical implications of dietary nitrate in populations with decreased NO bioavailability and associated endothelial disfunction (and elevated oxidative stress). In such populations, dietary nitrate may provide benefit. However, in a healthy cohort, dietary nitrate exerts minimal effects.

scholarly journals Dietary nitrate supplementation attenuates the reduction in exercise tolerance following blood donation

2016 ◽  
Vol 311 (6) ◽  
pp. H1520-H1529 ◽  
Author(s):  
Sinead T. J. McDonagh ◽  
Anni Vanhatalo ◽  
Jonathan Fulford ◽  
Lee J. Wylie ◽  
Stephen J. Bailey ◽  
...  
Keyword(s):  
Exercise Tolerance ◽  
Peak Power ◽  
Blood Donation ◽  
Hemoglobin Concentration ◽  
Moderate Intensity ◽  
Beetroot Juice ◽  
Moderate Intensity Exercise ◽  
Exercise Tests ◽  
Dietary Nitrate ◽  
Nitrate Supplementation

We tested the hypothesis that dietary nitrate (NO3−)-rich beetroot juice (BR) supplementation could partially offset deteriorations in O2transport and utilization and exercise tolerance after blood donation. Twenty-two healthy volunteers performed moderate-intensity and ramp incremental cycle exercise tests prior to and following withdrawal of ∼450 ml of whole blood. Before donation, all subjects consumed seven 70-ml shots of NO3−-depleted BR [placebo (PL)] in the 48 h preceding the exercise tests. During the 48 h after blood donation, subjects consumed seven shots of BR (each containing 6.2 mmol of NO3−, n = 11) or PL ( n = 11) before repeating the exercise tests. Hemoglobin concentration and hematocrit were reduced by ∼8–9% following blood donation ( P < 0.05), with no difference between the BR and PL groups. Steady-state O2uptake during moderate-intensity exercise was ∼4% lower after than before donation in the BR group ( P < 0.05) but was unchanged in the PL group. The ramp test peak power decreased from predonation (341 ± 70 and 331 ± 68 W in PL and BR, respectively) to postdonation (324 ± 69 and 322 ± 66 W in PL and BR, respectively) in both groups ( P < 0.05). However, the decrement in performance was significantly less in the BR than PL group (2.7% vs. 5.0%, P < 0.05). NO3−supplementation reduced the O2cost of moderate-intensity exercise and attenuated the decline in ramp incremental exercise performance following blood donation. These results have implications for improving functional capacity following blood loss.

Abstract P134: Preliminary Data: Dietary Nitrate Supplementation Does Not Extend Dry Static Apnea Or Wingate Performance

Circulation ◽  
2021 ◽  
Vol 143 (Suppl_1) ◽  
Author(s):  
Colin Carriker ◽  
Phillip Armentrout ◽  
Sarah Levine ◽  
James Smoliga
Keyword(s):  
Power Output ◽  
Preliminary Data ◽  
Repeated Measures ◽  
Peak Power ◽  
Hold Time ◽  
Wingate Test ◽  
Peak Power Output ◽  
Breath Hold ◽  
Dietary Nitrate ◽  
Nitrate Supplementation

Introduction: Previous studies have examined dietary nitrate supplementation and its effects on dry static apnea, and peak power. Dietary nitrate supplementation has been found to increase maximal apnea and peak power output. The purpose of this study was to determine the effects of beetroot juice on dry static apnea and Wingate performance. Hypothesis: Dietary nitrate will improve maximal breath hold time and peak power output. Dietary nitrate will improve tolerance to CO2, thereby improving maximal breath hold time and anaerobic capacity. Methods: In a randomized, double-blind, counterbalanced study, five healthy males (20.4±0.89 years) visited the lab on 3 separate occasions each separated by one week. Visit 1 served as a Wingate and breath hold familiarization visit. Prior to visits 2 and 3 participants were instructed to drink a beverage either a placebo (negligible nitrate content, PL) or dietary nitrate rich beverage (12.4 mmol nitrate, NIT) during the 4 days leading up to their next visit. Visits 2 and 3 consisted of two submaximal breath holds (80% of maximal determined during visit 1), with 2 minutes of rest between and three minutes of rest preceding the final breath hold for maximal duration. Finally, participants completed a standardized 10-minute warmup on the cycle ergometer before completing a 30-second maximal effort Wingate test. Results: A linear mixed effects model was used to determine whether treatment (NIT vs. PL) was associated with differences in VCO2 or PetCO2. Time (0, 10, 20, 30 min post-breath hold) and Treatment both served as repeated measures. Models were developed using multiple repeated measures covariance matrix structures, and the model with the lowest AIC was chosen as the final model. The interaction between time and treatment was included in the original models, and was removed if it was not statistically significant. Time was a statistically significant factor for VCO2 and PetCO2 (p < 0.001). Treatment, and the Time x Treatment interaction was not significant for either variable. No differences between NIT and PL were observed during the Wingate test for either time to peak power (5.02±2.45 and 6.2±2.43 sec, respectively) or maximal power (9.73±1.01 and 9.72±1.03 watts/kg, respectively) and fatigue index (49.42±14.98 and 47.30±6.99 watts/sec, respectively). Conclusion: Preliminary data indicates that in a general population four days of dietary nitrate supplementation may not improve breath hold time, tolerance to carbon dioxide in the lungs, or Wingate performance.

Dietary nitrate supplementation in COPD: An acute, double-blind, randomized, placebo-controlled, crossover trial☆

Nitric Oxide ◽  
2015 ◽  
Vol 44 ◽  
pp. 105-111 ◽  
Author(s):  
Conor P. Kerley ◽  
Kathleen Cahill ◽  
Kenneth Bolger ◽  
Aisling McGowan ◽  
Conor Burke ◽  
...  
Keyword(s):  
Crossover Trial ◽  
Double Blind ◽  
Dietary Nitrate ◽  
Nitrate Supplementation

scholarly journals The Effect of Dietary Nitrate Supplementation on Physiology and Performance in Trained Cyclists

2017 ◽  
Vol 12 (5) ◽  
pp. 684-689 ◽  
Author(s):  
Joseph A. McQuillan ◽  
Deborah K. Dulson ◽  
Paul B. Laursen ◽  
Andrew E. Kilding
Keyword(s):  
Time Trial ◽  
Crossover Design ◽  
Moderate Intensity ◽  
Beetroot Juice ◽  
Double Blind ◽  
Dietary Nitrate ◽  
Performance Time ◽  
Exercise Economy ◽  
Nitrate Supplementation ◽  
And Performance

Purpose:To determine the effect of dietary nitrate (NO3 –) supplementation on physiology and performance in well-trained cyclists after 6–8 d of NO3 – supplementation.Methods:Eight competitive male cyclists (mean ± SD age 26 ± 8 y, body mass 76.7 ± 6.9 kg, VO2peak 63 ± 4 mL · kg–1 · min–1) participated in a double-blind, placebo-controlled, crossover-design study in which participants ingested 70 mL of beetroot juice containing ~4 mmol NO3 – (NIT) or a NO3 –-depleted placebo (PLA), each for 8 d. Replicating pretreatment measures, participants undertook an incremental ramp assessment to determine VO2peak and first (VT1) and second (VT2) ventilatory thresholds on d 6 (NIT6 and PLA6), moderate-intensity cycling economy on d 7 (NIT7 and PLA7), and a 4-km time trial (TT) on d 8 (NIT8 and PLA8).Results:Relative to PLA, 6 d of NIT supplementation produced unclear effects for VO2peak (mean ± 95% confidence limit: 1.8% ± 5.5%) and VT1 (3.7% ± 12.3%) and trivial effects for both VT2 (–1.0% ± 3.0%) and exercise economy on d 7 (–1.0% ± 1.6%). However, effects for TT performance time (–0.7% ± 0.9%) and power (2.4% ± 2.5%) on d 8 were likely beneficial.Conclusions:Despite mostly unclear outcomes for standard physiological determinants of performance, 8 d of NO3 – supplementation resulted in likely beneficial improvements to 4-km TT performance in well-trained male endurance cyclists.

scholarly journals Dietary interventions for fetal growth restriction - therapeutic potential of dietary nitrate supplementation in pregnancy

2017 ◽  
Vol 595 (15) ◽  
pp. 5095-5102 ◽  
Author(s):  
Elizabeth Cottrell ◽  
Teresa Tropea ◽  
Laura Ormesher ◽  
Susan Greenwood ◽  
Mark Wareing ◽  
...  
Keyword(s):  
Fetal Growth ◽  
Fetal Growth Restriction ◽  
Therapeutic Potential ◽  
Growth Restriction ◽  
Dietary Interventions ◽  
Dietary Nitrate ◽  
Nitrate Supplementation ◽  
In Pregnancy

scholarly journals Acute beetroot juice supplementation on sympathetic nerve activity: a randomized, double-blind, placebo-controlled proof-of-concept study

2017 ◽  
Vol 313 (1) ◽  
pp. H59-H65 ◽  
Author(s):  
Karambir Notay ◽  
Anthony V. Incognito ◽  
Philip J. Millar
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Sympathetic Outflow ◽  
Beetroot Juice ◽  
Proof Of Concept ◽  
Burst Frequency ◽  
Double Blind ◽  
Dietary Nitrate ◽  
Nitrate Supplementation ◽  
Central Sympathetic Outflow

Acute dietary nitrate ([Formula: see text]) supplementation reduces resting blood pressure in healthy normotensives. This response has been attributed to increased nitric oxide bioavailability and peripheral vasodilation, although nitric oxide also tonically inhibits central sympathetic outflow. We hypothesized that acute dietary [Formula: see text] supplementation using beetroot (BR) juice would reduce blood pressure and muscle sympathetic nerve activity (MSNA) at rest and during exercise. Fourteen participants (7 men and 7 women, age: 25 ± 10 yr) underwent blood pressure and MSNA measurements before and after (165–180 min) ingestion of 70ml high-[Formula: see text] (~6.4 mmol [Formula: see text]) BR or [Formula: see text]-depleted BR placebo (PL; ~0.0055 mmol [Formula: see text]) in a double-blind, randomized, crossover design. Blood pressure and MSNA were also collected during 2 min of static handgrip (30% maximal voluntary contraction). The changes in resting MSNA burst frequency (−3 ± 5 vs. 3 ± 4 bursts/min, P = 0.001) and burst incidence (−4 ± 7 vs. 4 ± 5 bursts/100 heart beats, P = 0.002) were lower after BR versus PL, whereas systolic blood pressure (−1 ± 5 vs. 2 ± 5 mmHg, P = 0.30) and diastolic blood pressure (4 ± 5 vs. 5 ± 7 mmHg, P = 0.68) as well as spontaneous arterial sympathetic baroreflex sensitivity ( P = 0.95) were not different. During static handgrip, the change in MSNA burst incidence (1 ± 8 vs. 8 ± 9 bursts/100 heart beats, P = 0.04) was lower after BR versus PL, whereas MSNA burst frequency (6 ± 6 vs. 11 ± 10 bursts/min, P = 0.11) as well as systolic blood pressure (11 ± 7 vs. 12 ± 8 mmHg, P = 0.94) and diastolic blood pressure (11 ± 4 vs. 11 ± 4 mmHg, P = 0.60) were not different. Collectively, these data provide proof of principle that acute BR supplementation can decrease central sympathetic outflow at rest and during exercise. Dietary [Formula: see text] supplementation may represent a novel intervention to target exaggerated sympathetic outflow in clinical populations. NEW & NOTEWORTHY The hemodynamic benefits of dietary nitrate supplementation have been attributed to nitric oxide-mediated peripheral vasodilation. Here, we provide proof of concept that acute dietary nitrate supplementation using beetroot juice can decrease muscle sympathetic outflow at rest and during exercise in a normotensive population. These results have applications for targeting central sympathetic overactivation in disease.

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