Inorganic Nitrate Research Articles

Regulatory effect of dietary nitrate on blood pressure: a meta-analysis of randomized controlled trials.

Hypertension is the leading risk factor for global disease burden. Many clinical studies have reported that dietary inorganic nitrate can affect blood pressure. In this study, the PubMed, Embase, and Cochrane Library databases were searched for relevant literature published before December 2021 to explore the preventive and therapeutic effects of inorganic nitrate on hypertension. Two reviewers evaluated the randomized controlled trials of inorganic nitrates. This study included a total of 19 articles. The analyzed outcomes of the study were systolic, diastolic and mean arterial blood pressures as well as 24-hour ambulatory blood pressure. RevMan 5.4 was used to conduct meta-analysis. In the healthy population, inorganic nitrate lowered systolic blood pressure (-2.42 mmHg, 95% confidence intervals (CI) [-4.28, -0.57]; P = 0.01) but not diastolic blood pressure (-0.58 mmHg, 95% CI [-1.84, 0.68]; P = 0.36) or mean arterial pressure (-1.01 mmHg, 95% CI [-3.55, 1.54]; P = 0.44). However, in the hypertensive population, inorganic nitrates did not lower systolic blood pressure (-0.82 mmHg, 95% CI [-2.53, 0.90]; P = 0.35), diastolic blood pressure (-0.03 mmHg, 95% CI [-1.35, 1.30]; P = 0.97), 24-hour ambulatory systolic blood pressure (-0.22 mmHg, 95% CI [-1.50, 1.94]; P = 0.8), or 24-hour ambulatory diastolic blood pressure (-0.33 mmHg, 95% CI [-2.03, 1.37]; P = 0.7). In conclusion, inorganic nitrate can mildly reduce systolic blood pressure in healthy people, but does not have a lowering effect on blood pressure in patients with hypertension. Further research is required to obtain more definitive data and prove the link between inorganic nitrate and blood pressure.

PS-P07-7: IMPACT OF INORGANIC NITRATE ON ENDOTHELIAL FUNCTION IN ADULTS A SYSTEMATIC REVIEW OF RANDOMISED CONTROLLED TRIALS AND META ANALYSIS

Aim: Inorganic nitrate which is found in green leafy vegetables and beetroot reduces blood pressure via the nitrate-nitrite-NO pathway and may have other benefits such as improved endothelial function. It is assumed that endothelial dysfunction is key risk factor for CVDs. Therefore, in this systematic review and meta-analysis, we evaluated the impact of inorganic nitrate supplementation on endothelial function. Design and method: MEDLINE, Web of Science, and Scopus databases were searched by two independent authors up to November 2021. We included randomised controlled trials that test oral administration of dietary/non-dietary inorganic nitrate versus a control, adult male and female subjects with/without health conditions, measuring endothelial function by flow mediated dilatation (FMD) as an outcome. Risk and quality assessments were performed using a Cochrane risk of bias score and standardised mean differences of the outcomes were pooled using a random-effects model. Results: 3,521 studies were identified after a database search, of which 12 studies met the inclusion criteria. The pooled sample size was 362 and the number of participants per trial ranged from 10 to 65. Eight studies were acute, four studies were chronic and most of them included healthy participant arms (n = 12) with (n = 4) focusing on unhealthy populations. The mean difference in %FMD for nitrate versus the control was 1.57% (95% CI: 0.76–2.37), p = 0.01; high heterogeneity (I2 = 98.3%) was observed (Figure 1). Subgroup analyses were performed in terms of, nitrate amount (< more or less than 600 mg), type of intervention (dietary or non-dietary), participants health status (healthy and unhealthy), and study duration (acute or chronic). All sub-analysis still showed significant increases in %FMD. In acute studies, FMD response was higher (2.13% (95% CI: 0.87–3.40), p < 0.01, I2 = 98.5%) than chronic studies (0.90% (95% CI: 0.48–1.31), p < 0.01, I2 = 68.6%). Only one study showed low risk of bias; the other studies were classified as “some concern” due to a lack of information about randomisation and lack of pre-specified analysis plans. Conclusions: The meta-analysis provides evidence that inorganic nitrate improves FMD response and may be a useful strategy for preventing further CVD. Change in 1.5% of FMD as seen in this review could results in a reduction in CVD risk of ∼15%. However, due to the high heterogeneity of the results, further studies are needed to build a robust evidence base to inform dietary recommendations.

PH affects the aqueous-phase nitrate-mediated photooxidation of phenolic compounds: implications for brown carbon formation and evolution.

Brown carbon (BrC) is known to have important impacts on atmospheric chemistry and climate. Phenolic compounds are a prominent class of BrC precursors that are emitted in large quantities from biomass burning and fossil fuel combustion. Inorganic nitrate is a ubiquitous component of atmospheric aqueous phases such as cloudwater, fog, and aqueous aerosols. The photolysis of inorganic nitrate can lead to BrC formation via the photonitration of phenolic compounds in the aqueous phase. However, the acidity of the atmospheric aqueous phase adds complexity to these photonitration processes and needs to be considered when investigating BrC formation from the nitrate-mediated photooxidation of phenolic compounds. In this study, we investigated the influence of pH on the formation and evolution of BrC from the aqueous-phase photooxidation of guaiacol, catechol, 5-nitroguaiacol, and 4-nitrocatechol initiated by inorganic nitrate photolysis. The reaction rates, BrC composition and quantities were found to depend on the aqueous phase pH. Guaiacol, catechol, and 5-nitroguaiacol reacted substantially faster at lower pH. In contrast, 4-nitrocatechol reacted at slower rates at lower pH. For all four phenolic compounds, the initial stages of photooxidation resulted in an increase in light absorption (i.e., photo-enhancement) in the near-UV and visible range due to the formation of light absorbing products formed via the addition of nitro and/or hydroxyl groups to the phenolic compound. Greater photo-enhancement was observed at lower pH during the nitrate-mediated photooxidation of guaiacol and catechol. In contrast, greater photo-enhancement was observed at higher pH during the nitrate-mediated photooxidation of 5-nitroguaiacol and 4-nitrocatechol. This indicated that the effect that the aqueous phase pH has on the composition and yields of BrC formed is not universal, and will depend on the initial phenolic compound. These results provide new insights into how the atmospheric aqueous phase acidity influences the reactivities of different phenolic compounds and BrC formation/evolution during photooxidation initiated by inorganic nitrate photolysis, which will have significant implications for how the atmospheric fates of phenolic compounds and BrC formation/evolution are modeled for areas with high levels of inorganic nitrate.

Association of Urinary Nitrate With Diabetes Complication and Disease-Specific Mortality Among Adults With Hyperglycemia.

The hyperglycemia condition disrupts metabolism of nitrate/nitrite and nitric oxide, and dietary nitrate intake can restore nitric oxide homeostasis. This study aims to examine whether urinary nitrate is associated with diabetes complications and long-term survival among people with hyperglycemia. A total of 6208 people with hyperglycemia who participated in the National Health and Nutrition Examination Survey from 2005 to 2014 were enrolled. Diabetes complications included congestive heart failure, coronary heart disease, angina, stroke, myocardial infarction, diabetic retinopathy, and nephropathy. Mortality was obtained from the National Death Index until 2015. Urinary nitrate was measured by ion chromatography coupled with electrospray tandem mass spectrometry, which was log-transformed and categorized into tertiles. Logistic regression models and Cox proportional hazards models were respectively performed to assess the association of urinary nitrate with the risk of diabetes complications and disease-specific mortalities. After adjustment for potential confounders, including urinary perchlorate and thiocyanate, compared with the participants in the lowest tertile of nitrate, the participants in the highest tertile had lower risks of congestive heart failure (odds ratio [OR] 0.41; 95% CI, 0.27-0.60) and diabetic nephropathy (OR 0.50; 95% CI, 0.41-0.62). Meanwhile, during a total follow-up period of 41 463 person-years, the participants in the highest tertile had lower mortality risk of all-cause (hazard ratio [HR] 0.78; 95% CI, 0.62-0.97), cardiovascular disease (CVD) (HR 0.56; 95% CI, 0.37-0.84), and diabetes (HR 0.47; 95% CI, 0.24-0.90), which showed dose-dependent linear relationships (P for nonlinearity > 0.05). Moreover, no association between nitrate and cancer mortality was observed (HR 1.13; 95% CI, 0.71-1.80). Higher urinary nitrate is associated with lower risk of congestive heart failure and diabetic nephropathy, and lower risk of all-cause, CVD, and diabetes mortalities. These findings indicate that inorganic nitrate supplementation can be considered as a supplementary treatment for people with hyperglycemia.

Fjords of the western and northern regions of Svalbard harbour distinct bacterioplankton community structures.

Fjords are highly dynamic ecosystems that are known to be sentinels to climate change due to increased glaciomarine interactions. The convergence and mixing of warm Atlantic water (AtW) and cold Arctic water (ArW) is known to influence the hydrodynamics and ecology of the Arctic fjords. However, most past studies were limited to single-fjord ecosystems, determining the baseline knowledge of inter-fjord comparison on bacterioplankton diversity and distribution patterns. In the present study, we investigated the bacterial diversity and community composition across three Arctic fjords located in the western and northern regions of Svalbard. Our observations show that the bacterial community structure varied significantly among the fjords, while abundant Operational Taxonomic Units (OTUs) were widespread (n = 100) between all the samples and rare OTUs (n = 2221) mainly contributed to these differences. Phylogenetic classification revealed that Alpha (27.3-55%) and Gamma-proteobacteria (16-51.3%), followed by Bacteroidota (17-35.7%) were dominant in the St.Jonsfjorden and Magdalenefjorden, while Verrucomicrobiota (up to 84.19%) and Actinobacteriota (up to 76.5%) were predominant in the Raudfjorden. Temperature, dissolved inorganic phosphate (DIP) and depth were found to significantly influence the community composition of abundant bacterial groups, whereas the rare bacterial groups were affected by temperature, DIP, dissolved inorganic nitrate (DIN), ammonium and depth. A comparative meta-analysis along with Kongsfjorden and Krossfjorden also showed that each fjord had a significantly different bacterioplankton community structure.

Local delivery of nitric oxide prevents endothelial dysfunction in periodontitis

AimsIncreased cardiovascular disease risk underlies elevated rates of mortality in individuals with periodontitis. A key characteristic of those with increased cardiovascular risk is endothelial dysfunction, a phenomenon synonymous with deficiencies of bioavailable nitric oxide (NO), and prominently expressed in patients with periodontitis. Also, inorganic nitrate can be reduced to NO in vivo to restore NO levels, leading us to hypothesise that its use may be beneficial in reducing periodontitis-associated endothelial dysfunction. Herein we sought to determine whether inorganic nitrate improves endothelial function in the setting of periodontitis and if so to determine the mechanisms underpinning any responses seen. Methods and resultsPeriodontitis was induced in mice by placement of a ligature for 14 days around the second molar. Treatment in vivo with potassium nitrate, either prior to or following establishment of experimental periodontitis, attenuated endothelial dysfunction, as determined by assessment of acetylcholine-induced relaxation of aortic rings, compared to control (potassium chloride treatment). These beneficial effects were associated with a suppression of vascular wall inflammatory pathways (assessed by quantitative-PCR), increases in the anti-inflammatory cytokine interleukin (IL)-10 and reduced tissue oxidative stress due to attenuation of xanthine oxidoreductase-dependent superoxide generation. In patients with periodontitis, plasma nitrite levels were not associated with endothelial function indicating dysfunction. ConclusionOur results suggest that inorganic nitrate protects against, and can partially reverse pre-existing, periodontitis-induced endothelial dysfunction through restoration of nitrite and thus NO levels. This research highlights the potential of dietary nitrate as adjunct therapy to target the associated negative cardiovascular outcomes in patients with periodontitis.

Inorganic nitrate supplementation may improve diastolic function and the O2 cost of exercise in cancer survivors: a pilot study

In non-cancer populations, inorganic dietary nitrate (NO3-) supplementation is associated with enhanced cardiorespiratory function but remains untested in patients with a history of cancer. Therefore, this pilot study sought to determine if oral NO3- supplementation, as a supportive care strategy, increases left ventricular (LV) function and exercise performance in survivors of cancer treated with anticancer therapy while simultaneously evaluating the feasibility of the methods and procedures required for future large-scale randomized trials. Two cohorts of patients with a history of cancer treated with anticancer chemotherapy were recruited. Patients in cohort 1 (n = 7) completed a randomized, double-blind, crossover study with 7days of NO3- or placebo (PL) supplementation, with echocardiography. Similarly, patients in cohort 2 (n = 6) received a single, acute dose of NO3- supplementation or PL. Pulmonary oxygen uptake (VO2), arterial blood pressure, and stroke volume were assessed during exercise. In cohort 1, NO3- improved LV strain rate in early filling (mean difference (MD) [95% CI]: - 0.3 1/s [- 0.6 to 0.06]; P = 0.04) and early mitral septal wall annular velocity (MD [95% CI]: 0.1m/s [- 0.01 to - 0.001]; P = 0.02) compared to placebo. In cohort 2, NO3- decreased the O2 cost of low-intensity steady-state exercise (MD [95% CI]: - 0.5ml/kg/min [- 0.9 to - 0.09]; P = 0.01). Resting and steady-state arterial blood pressure and stroke volume were not different between conditions. No differences between conditions for peak VO2 (MD [95% CI]: - 0.7ml/kg/min [- 3.0 to 1.6]; P = 0.23) were observed. The findings from this pilot study warrant further investigation in larger clinical trials targeting the use of long-term inorganic dietary NO3- supplementation as a possible integrative supportive care strategy in patients following anticancer therapy.

Influence of Metal Salts Addition on Physical and Electrochemical Properties of Ethyl and Propylammonium Nitrate.

In this work, we deepen in the characterization of two protic ionic liquids (PILs), ethylammonium nitrate (EAN) and propylammonium nitrate (PAN). With this aim, we determined the influence of inorganic nitrate salts addition on their physical properties and their electrochemical potential window (EPW). Thus, experimental measurements of electrical conductivity, density, viscosity, refractive index and surface tension of mixtures of {EAN or PAN + LiNO3, Ca(NO3)2, Mg(NO3)2 or Al(NO3)3} at a temperature range between 5 and 95 °C are presented first, except for the last two properties which were measured at 25 °C. In the second part, the corresponding EPWs were determined at 25 °C by linear sweep voltammetry using three different electrochemical cells. Effect of the salt addition was associated mainly with the metal cation characteristics, so, generally, LiNO3 showed the lower influence, followed by Ca(NO3)2, Mg(NO3)2 or Al(NO3)3. The results obtained for the EAN + LiNO3 mixtures, along with those from a previous work, allowed us to develop novel predictive equations for most of the presented physical properties as functions of the lithium salt concentration, the temperature and the water content. Electrochemical results showed that a general order of EPW can be established for both PILs, although exceptions related to measurement conditions and the properties of the mixtures were found.

Studies on synthesis, structural, thermal, optical, spectral and mechanical properties of an inorganic strontium nitrate NLO single crystal

An inorganic NLO single crystal of strontium nitrate (SrN) was successfully grown from an aqueous solution, by slow evaporation technique at ambient temperature. Good transparent SrN crystals were obtained within 2 weeks. Various characterizations were carried out to ensure the application of the grown material. Single crystal XRD study reveals that the crystal shows a cubic structure with a centrosymmetric Pa3¯ space group. The crystalline nature of the compound was confirmed by powder X-ray diffraction. The unit cell dimension of the SrN crystal was found to be, a=b=c=7.8220 Å, and the axial angle is α =β=γ=90°. The average crystalline size of the material was 52 nm. The various functional groups associated with grown crystals have been characterized by FTIR and FT-Raman spectroscopy studies. The lower cut-off wavelength is found to be 320 nm and the band gap energy of the SrN crystal was 3.9 eV. The synthesized crystal exhibits 84% transmittance in the visible region. The grown crystals were thermally stable up to 135 °C. Various mechanical parameters such as microhardness (Hv), work hardening coefficient (n), elastic stiffness (C11), and yield strength (σy) of the grown material have been carried out by the indentation method. The nonlinear refractive index (n2), nonlinear absorption coefficient (β), and third order nonlinear susceptibility (χ(3)) were studied using the Z-scan technique, which involves open and closed aperture measurements with a continuous wave laser of 632.8 nm.

Human skeletal muscle nitrate and nitrite in individuals with peripheral arterial disease: Effect of inorganic nitrate supplementation and exercise.

Skeletal muscle may act as a reservoir for N-oxides following inorganic nitrate supplementation. This idea is most intriguing in individuals with peripheral artery disease (PAD) who are unable to endogenously upregulate nitric oxide. This study analyzed plasma and skeletal muscle nitrate and nitrite concentrations along with exercise performance, prior to and following 12-weeks of exercise training combined with oral inorganic nitrate supplementation (EX+BR) or placebo (EX+PL) in participants with PAD. Non-supplemented, at baseline, there were no differences in plasma and muscle nitrate. For nitrite, muscle concentration was higher than plasma (+0.10nmol.g-1 ). After 12 -weeks, acute oral nitrate increased both plasma and muscle nitrate (455.04 and 121.14 nmol.g-1 , p < 0.01), which were correlated (r=0.63, p < 0.01), plasma nitrate increase was greater than in muscle (p < 0.01). Nitrite increased in the plasma (1.01 nmol.g-1 , p < 0.05) but not in the muscle (0.22 nmol.g-1 ) (p < 0.05 between compartments). Peak walk time (PWT) increased in both groups (PL + 257.6s;BR + 315.0s). Six-minute walk (6MW) distance increased only in the (EX+BR) group (BR + 75.4m). We report no substantial gradient of nitrate (or nitrite) from skeletal muscle to plasma, suggesting a lack of reservoir-like function in participants with PAD. Oral nitrate supplementation produced increases in skeletal muscle nitrate, but not skeletal muscle nitrite. The related changes in nitrate concentration between plasma and muscle suggests a potential for inter-compartmental nitrate "communication". Skeletal muscle did not appear to play a role in within compartment nitrate reduction. Muscle nitrate and nitrite concentrations did not appear to contribute to exercise performance in patients with PAD.

Effects of Acute Beetroot Juice Ingestion on Reactive Agility Performance

Beetroot juice (BRJ) is high in inorganic nitrate (NO3) which has been shown to enhance vascular function, cognition, and physical performance. Acute BRJ supplementation has been reported to enhance explosive resistance exercise performance and simple reaction time in diseased populations. However, it remains unknown if acute BRJ supplementation can enhance agility and reactive drills in healthy individuals, which are relevant to many sports. The purpose of this study was to investigate the effects of acute BRJ supplementation on simple reaction time and reactive agility performance. In a counterbalanced double-blinded manner, physically active males completed two trials each with a differing single-dose treatment: (1) Placebo (PL), (2) BRJ. Each treatment was consumed 2-hrs before experimental testing. Plasma Nitrate (NO3) and Nitrite (NO2) were measured via capillary blood sampling and colorimetric assay. Reaction time was assessed using a simple reaction time light test. Reactive agility was measured via a semi-circle drill and a get-up-and-go drill. All tests used FITLIGHT LED sensors to record response time. Each visit was separated by a 72-h washout period. Acute BRJ ingestion resulted in significantly greater plasma NO3 (p &lt; 0.001) and NO2 (p = 0.008) compared to PL. BRJ significantly improved response time during the semi-circle drill (p = 0.011) and get-up and go drill (p = 0.027) compared to PL. No differences between treatments were observed for simple reaction time (p = 0.279). Collectively, these findings suggest that acute BRJ ingestion may improve reactive agility performance likely mediated by systemic increases in NO3/NO2. Future research is needed to investigate how these findings translate to game-play and sports competition.

Carbon and nitrogen uptake through photosynthesis and feeding by photosymbiotic Acantharia

Background: Mixotrophy, combining phagotrophy and photoautotrophy in order to acquire nutrients and energy, is a widespread trophic mode in marine protist plankton. Acantharia (Radiolaria) are ubiquitous, but still uncultured oceanic protists. Many of them are mixoplanktic by endosymbiotic relations with microalgae. Here we aimed at quantitatively assessing phototrophy (inorganic nutrients) and phagotrophy (organic nutrients) of photosymbiotic Acantharia, to understand their physiology, and thereby improve integrations of mixotrophy into ecological models of oceanic ecosystems. Methods: Freshly collected Acantharia were incubated with stable isotopes of inorganic carbon and nitrogen to determine photosynthetic uptake rates. Grazing experiments (prey disappearance) were done with different algal cultures as potential food organisms to measure the contribution of prey ingestion to the acantharian metabolism. Fluorescently (and isotopically) labelled prey was used to verify prey uptake, qualitatively. Results/Conclusions: Carbon uptake rates were unaffected by the nitrogen source (i.e., nitrate or ammonium). Total carbon inorganic uptake rate was 1112±82 pgC h-1 Acantharia‑1, 22.3±1.6 pgC h-1 symbiont cell-1assuming 50 symbionts per Acantharia, at ~155-μmol photons m−2 s−1 irradiance. The Acantharia studied could use both inorganic ammonium and nitrate, but ammonium was taken up at a ~5 times higher rate. Prey ingestion of the haptophyte, Isochrysis galbana, was detected using labelled algae. Significant grazing by Acantharia could only be established on the dinoflagellate Effrenium voratum, with a grazing rate of 728 prey Acantharia‑1 hour-1 (i.e., ~56.3 ngC h-1, 46% of total holobiont carbon content) at a ratio of 1.06x104 prey predator-1. Daily photosynthetic carbon uptake rates made up ~14.5% of the total holobiont carbon content (0.9% hourly). The extent to which photosynthates are used and assimilated by the acantharian cell and/or if it is used for catabolic processes to obtain energy is still to be studied. Isotopic ratios further suggests seasonal differences in the usage of each trophic mode.

A Novel ZnO Nanoparticles Enhanced Surfactant Based Viscoelastic Fluid Systems for Fracturing under High Temperature and High Shear Rate Conditions: Synthesis, Rheometric Analysis, and Fluid Model Derivation.

Surfactant-based viscoelastic (SBVE) fluids are innovative nonpolymeric non-newtonian fluid compositions that have recently gained much attention from the oil industry. SBVE can replace traditional polymeric fracturing fluid composition by mitigating problems arising during and after hydraulic fracturing operations are performed. In this study, SBVE fluid systems which are entangled with worm-like micellar solutions of cationic surfactant: cetrimonium bromide or CTAB and counterion inorganic sodium nitrate salt are synthesized. The salt reagent concentration is optimized by comparing the rheological characteristics of different concentration fluids at 25 °C. The study aims to mitigate the primary issue concerning these SBVE fluids: significant drop in viscosity at high temperature and high shear rate (HTHS) conditions. Hence, the authors synthesized a modified viscoelastic fluid system using ZnO nanoparticle (NPs) additives with a hypothesis of getting fluids with improved rheology. The rheology of optimum fluids of both categories: with (0.6 M NaNO3 concentration fluid) and without (0.8 M NaNO3 concentration fluid) ZnO NPs additives were compared for a range of shear rates from 1 to 500 Sec−1 at different temperatures from 25 °C to 75 °C to visualize modifications in viscosity values after the addition of NPs additives. The rheology in terms of viscosity was higher for the fluid with 1% dispersed ZnO NPs additives at all temperatures for the entire range of shear rate values. Additionally, rheological correlation function models were derived for the synthesized fluids using statistical analysis methods. Subsequently, Herschel–Bulkley models were developed for optimum fluids depending on rheological correlation models. In the last section of the study, the pressure-drop estimation method is described using given group equations for laminar flow in a pipe depending on Herschel–Bulkley-model parameters have been identified for optimum fluids are consistency, flow index and yield stress values.

The Effect Of Inorganic Nitrate On Muscle Function In Healthy Females Across The Menstrual Cycle

PURPOSE: Inorganic nitrate (NO3-) supplementation increases nitric oxide (NO) bioavailability and may improve exercise performance. In females, estrogen increases endogenous eNOS production of NO, but estrogen fluctuates throughout the menstrual cycle (MC). It is unknown if different phases of the MC or exogenous NO3- supplementation impact maximal voluntary isometric contraction (MVIC), isokinetic torque, or power in apparently healthy young females. The purpose of this study was to examine potential differences in MVIC, isokinetic torque, and power across the early (EF) and late follicular (LF) phase of the MC, and after either beetroot juice (NO3-containing ~13 mmol NO3-) or identical placebo (PL) supplementation. METHODS: Seven recreationally active women (age: 24.7 ± 4 yrs, VO2peak: 34.4 ± 8 mL/kg/min) with normal MC who were not using contraceptives were recruited in this double-blinded crossover study. Subjects were randomized to consume NO3 or PL, twice daily, for at least 2 days prior to testing that was conducted during EF and again during LF (1-5 and 11-14 days after menses onset, respectively). Subjects also consumed the supplement 2 hours prior to the testing, and a 14-day washout period was utilized between treatments. A linear mixed effects model was used to determine differences between MC phase, across supplements, and interaction effects. MVIC (at 90°), peak torque (PT), PT normalized to bodyweight, time to PT, average PT, and average power were acquired via a Biodex isokinetic dynamometer during knee extension when measured at 180°, 270°, and 360°/second. Data are mean ± SD and significance was determined a priori at p ≤ 0.05. RESULTS: Mixed effects models revealed no significant differences in MVIC, power, or any measures of torque either across the MC, or between the PL and NO3 supplementations (all p ≥ 0.05). There were also no significant interaction effects for MVIC (PL EF: 1.12 ± 0.3; PL LF: 1.10 ± 0.3; NO3 EF: 1.18 ± 0.3; NO3 LF: 1.14 ± 0.3 Hz; p = 0.93) or any other outcomes. CONCLUSIONS: This preliminary data suggests that neither the follicular phase of the menstrual cycle, nor NO3- supplementation, impacts MVIC or outcomes such as peak torque or average power during isokinetic knee extension in healthy young females.

Dietary Nitrate Does Not Improve Neuromuscular Performance And Match-play Demands In Elite Female Hockey Players.

PURPOSE: Beetroot juice is a commonly used ergogenic aid that contains high levels of inorganic nitrate (NO3-) and that its intake has proven effectivity at increasing blood nitric oxide (NO) concentrations. The ingestion of beetroot juice has shown good evidence of benefits in endurance sports while team sports has been barely studied. In our knowledge, only a few studies have been developed in team sports athletes. The present study was designed to compare the acute effects of beetroot juice supplementation on physical performance and match-play demands in elite female field hockey players METHODS: Eleven well-trained female hockey players (22.78 ± 5.12 years) participated during the preparatory period of their hockey season in this study. Participants were randomly divided into two groups undergoing a neuromuscular test battery with ingestion of 70 mL beetroot juice (6.4 mmol NO3-) or 70 mL placebo (0.04 mmol NO3-) in two separated days with one week between protocols. A neuromuscular test battery consisted in different test such as; countermovement jump (CMJ), isometric handgrip strength (IHS), and repeated sprint ability test (RSA) were realized. Afterwards a simulated hockey match play (2 x 20 minutes) was realized and the data was recorded by Global Positioning System (GPS). RESULTS: No significant improvements were observed in any physical parameters analysed comparing beetroot juice versus placebo ingestion, CMJ (p = 0.776), IHS (p = 0.829), RSA (p = 0.466). Therefore, no differences were reported in any physical match demands measured by GPS (i.e., total distance covered, number of accelerations/decelerations, etc) (p = 0.063-0.941) CONCLUSIONS: Beetroot juice acute supplementation did not produce any statistically significant improvement in physical performance or match-play demands in elite female field hockey players

Factors that Moderate the Effect of Nitrate Ingestion on Exercise Performance in Adults: A Systematic Review with Meta-Analyses and Meta-Regressions

To identify how variables such as exercise condition, supplementation strategy, participant characteristics and demographics, and practices that control oral microbiota diversity could modify the effect of inorganic nitrate ingestion (as nitrate salt supplements, beetroot juice, and nitrate-rich vegetables) on exercise performance, we conducted a systematic review with meta-analysis. Studies were identified in PubMed, Embase, and Cochrane databases. Eligibility criteria included randomized controlled trials assessing the effect of inorganic nitrate on exercise performance in healthy adults. To assess the variation in effect size, we used meta-regression models for continuous variables and subgroup analysis for categorical variables. A total of 123 studies were included in this meta-analysis, comprising 1705 participants. Nitrate was effective for improving exercise performance (standardized mean difference [SMD]: 0.101; 95% CI: 0.051, 0.151, P<0.001, I2=0%), although nitrate salts supplementation was not as effective (P=0.629) as ingestion via beetroot juice (P<0.001) or a high-nitrate diet (P=0.005). Practices that control oral microbiota diversity influenced the nitrate effect, with practices harmful to oral bacteria decreasing the ergogenic effect of nitrate. The ingestion of nitrate was most effective for exercise lasting between 2 and 10 min(P<0.001). An inverse dose-response relation between the fraction of inspired oxygen and the effect size (coefficient: -0.045, 95% CI: -0.085, -0.005, P=0.028) suggests that nitrate was more effective in increasingly hypoxic conditions. There was a dose-response relation for acute administration (P=0.049). The most effective acute dose was between 5 and 14.9 mmolprovided ≥150 minprior to exercise (P<0.001). An inverse dose-response for protocols≥2 d was observed (P=0.025), with the optimal dose between 5 and 9.9 mmol·d-1 (P<0.001). Nitrate, via beetroot juice or a high-nitrate diet, improved exercise performance, in particular, in sessions lasting between 2 and 10 min.Ingestion of 5-14.9 mmol⋅d-1 taken ≥150 minprior to exercise appears optimal for performance gains and athletes should be aware that practices controlling oral microbiota diversity may decrease the effect of nitrate.

Carbon to Nitrogen Uptake Ratios Observed Across the Southern Ocean by the SOCCOM Profiling Float Array

AbstractMeasurements of pH and nitrate from the Southern Ocean Carbon and Climate Observations and Modeling array of profiling floats were used to assess the ratios of dissolved inorganic carbon (DIC) and nitrate (NO3) uptake during the spring to summer bloom period throughout the Southern Ocean. Two hundred and forty‐three bloom periods were observed by 115 floats from 30°S to 70°S. Similar calculations were made using the Takahashi surface DIC and nitrate climatology. To separate the effects of atmospheric CO2 exchange and mixing from phytoplankton uptake, the ratios of changes in DIC to nitrate of surface waters (ΔDIC/ΔNO3) were computed in the Biogeochemical Southern Ocean State Estimate (B‐SOSE) model. Phytoplankton uptake of DIC and nitrate are fixed in B‐SOSE at the Redfield Ratio (RR; 6.6 mol C/mol N). Deviations in the B‐SOSE ΔDIC/ΔNO3 must be due to non‐biological effects of CO2 gas exchange and mixing. ΔDIC/ΔNO3 values observed by floats and in the Takahashi climatology were corrected for the non‐biological effects using B‐SOSE. The corrected, in situ biological uptake ratio (C:N) occurs at values similar to the RR, with two major exceptions. North of 40°S biological DIC uptake is observed with little or no change in nitrate giving high C:N. In the latitude band at 55°S, the Takahashi data give a low C:N value, while floats are high. This may be due to a change in CO2 air‐sea exchange in this region from uptake during the Takahashi reference year of 2005 to outgassing of CO2 during the years sampled by floats.

Acute Effects of Inorganic Nitrate Intake on Brachial and Femoral Flow-Mediated Vasodilation, and on Carotid Artery Reactivity Responses: Results of a Randomized, Double-Blinded, Placebo-Controlled Cross-Over Study in Abdominally Obese Men.

Most trials on the effects of inorganic nitrate intake have focused on only one specific aspect of the endothelial cell response to a stimulus, thereby possibly missing other important effects. The aim of the present randomized, double-blinded, placebo-controlled cross-over study was therefore to investigate in eighteen healthy abdominally obese men (18–60 years, waist circumference ≥ 102 cm) acute effects of potassium nitrate on brachial and femoral flow-mediated vasodilation (FMD), and on carotid artery reactivity (CAR) to a cold pressure test. Participants received in random order a drink providing 10 mmol potassium nitrate (i.e., 625 mg of nitrate) or an iso-molar placebo drink with potassium chloride. Fasted and 4 h post-drink FMD and blood pressure measurements were performed. CAR responses were assessed at 4 h. Circulating nitrate plus nitrite concentration increased following nitrate intake (p = 0.003). Compared with placebo, potassium nitrate did not affect brachial (mean [95% confidence interval]: −0.2% [−2.5, 2.1], p = 0.86) and femoral FMD responses (−0.6% [−3.0; 1.7], p = 0.54). CAR responses were also not different (−0.8% [−2.5, 0.9], p = 0.32). Finally, changes in blood pressure and heart rate did not differ. No adverse events were observed. In conclusion, this trial did not provide evidence for effects of a single dose of inorganic nitrate on 4 h vascular endothelial function in abdominally obese men.

Dietary nitrate, aging and brain health: the latest evidence.

With an increasing population age, cognitive decline and age-associated neurodegenerative diseases are becoming increasingly prevalent and burdensome in society. Dietary supplementation with inorganic nitrate, which serves as a nitric oxide precursor, has been suggested as a potential nutritional strategy to improve brain health in older adults. In this review, we discuss recent findings in this area. A number of studies have emerged in the past 12-18 months exploring the effects of dietary nitrate supplementation on cognitive function, with typically (although not exclusively) null findings emerging. This research is characterized by small, acute/short-term studies, although observational studies and longer-duration randomised controlled trials are beginning to emerge. From the limited research reporting benefits of nitrate supplementation on cognitive function, one important discovery has been the identification of a potential pathway through which nitrate could impact cognitive health, involving modulation of the oral microbiome, which warrants further investigation. Despite some promising early findings, there is currently insufficient evidence to recommend increased dietary nitrate intake for the purpose of improving brain health. However, longer-term, larger-scale trials in potentially responsive groups are warranted to provide definitive evidence in this area.

AGRICULTURE AND ENVIRONMENT INTERACTION

The resources necessary for food production have shown a disquieting deterioration during the last three decades. Modern intensive agriculture has an adverse effect not only on the physical environment but also on human health. On the other hand, 'Sustainable Agricultural Systems', which has gained importance in recent years, deals with both the protection of natural resources and the increase in plant production. In these systems, production is ensured by directing the resources obtained from the system cycle, not the chemicals and inputs that harm human, plant and environmental health, and quality healthy products are obtained. In 'Organic Farming', which is one of the sustainable agricultural systems, it is aimed to cause the least damage to the environment by producing healthy foods without disturbing the natural balance. The risk of pollution is less because less economic input is used in these and similar protected sustainable agricultural systems. While the inputs used in agricultural production stage increase the productivity of the product produced per unit area and make it more resistant to diseases and pests, they can have negative effects on the living things in the immediate vicinity and the ecosystem. While the development of agriculture in a region positively affects the natural life, oxygen production and climate in the region, inorganic nitrate pollution, pesticide pollution and salinity problems can be listed as the negative effects of agriculture on the environment, especially in regions where intensive agriculture is practiced. Also, agricultural water use, application of fertilizers and pesticides may negatively affect the water courses, deforestation, and crop and animal raising may result in greenhouse gas emissions, unsuitable agricultural practices may have detrimental impacts on soil, genetic resources and biodiversity. In order to ensure sustainability in agriculture, by abandoning the agricultural production methods based on excessive chemical pesticides and fertilizers that the producers have applied until now; an economical fertilization, preserving the organic matter ratio of the soil by preventing stubble fires, reduced tillage, combating diseases, pests and weeds in integration with a suitable crop rotation are of great importance.