Nitrate Intake Research Articles

Nitrate-nitrite exposure through drinking water and diet and risk of colorectal cancer: A systematic review and meta-analysis of observational studies

Considerable controversy exists regarding the association between nitrate intake and risk of colorectal cancer. Therefore, we performed a dose-response meta-analysis of observational studies. We identified relevant studies by searching PubMed, Scopus and ISI Web of Knowledge until April 2020 and references of retrieved relevant articles. The random-effects model was used to calculate pooled effect size (ESs) and 95% confidence intervals (CIs). Fifteen prospective cohort and case-control papers were included in this systematic review and meta-analysis. In total, 2,573,524 participants with an age range between 20 and 85 years were included. The total number of colorectal cancer cases was 38,848. Intake of nitrate from diet was associated with a risk of colorectal cancer (Pooled HR: 1.13; 95% CI: 1.04-1.23, I2=38%; P=0.08). Nitrite in diet was not significantly associated with risk of colorectal cancer (pooled HR: 1.07; 95% CI: 0.95-1.21, I2=61.6%; P=0.005). Nitrate in water did not show an association with risk of colorectal cancer (pooled HR: 1.04; 95% CI: 0.92-1.19, I2=64.7%; P=0.002). Non-linear dose-response analysis revealed no significant association of dietary nitrite and also nitrate of drinking water with risk of colorectal cancer. However, dietary nitrate was marginally associated with a greater risk of colorectal cancer. Linear dose-response analysis of nitrate from diet was not associated with colorectal cancer risk by an additional 50mg per day. Such a non-significant association was also seen for colorectal cancer risk by an additional 1mg per day and 1mg/l from dietary nitrite and water nitrate respectively. Dietary nitrate was related to a higher risk of colorectal cancer risk. However, intake of nitrite from diet and nitrate from the drinking water was not associated with colorectal cancer risk.

Higher urinary nitrate was associated with lower prevalence of congestive heart failure: results from NHANES

BackgroundSome studies have reported that nitrate intake from vegetables was inversely associated with many vascular diseases, but few studies have paid attention to the relationship between urinary nitrate and cardiovascular diseases (CVDs). This cross-sectional study aimed to explore the connections between urinary nitrate and prevalence of CVDs.MethodsThe data of this study was collected from National Health and Nutrition Examination Survey (NHANES). Finally, several years’ data of NHANES were merged into 14,894 observations. Logistic regression models were used to examine the associations between urinary nitrate and CVDs by using the “survey” package in R software (version 3.2.3).ResultsIn the univariable logistic analysis, significant association was discovered between urinary nitrate and congestive heart failure, coronary heart disease, angina pectoris, myocardial infarction (all P < 0.001). By adjusting related covariates, the multivariable logistic analysis showed that the significant association only existed between urinary nitrate and congestive heart failure (OR = 0.651, 95% CI 0.507–0.838, P < 0.001). Compared to Q1 urinary nitrate level as reference, the risk for prevalent heart failure diminished along with increasing levels of urinary nitrates, (OR of Q2 level = 0.633, 95% CI 0.403–0.994), (OR of Q3 level = 0.425, 95% CI 0.230–0.783), (OR of Q4 level = 0.375, 95% CI 0.210–0.661), respectively. Moreover, urinary nitrate levels were associated with congestive heart failure in a dose-dependent manner in both 20–60 years group, 60+ years group and male, female group (P < 0.001, P = 0.011 and P = 0.009, P = 0.004).ConclusionsIndependent of related covariates, higher urinary nitrate was associated with lower prevalent congestive heart failure.

Drinking-water nitrate and cancer risk: A systematic review and meta-analysis

Background Nitrate is an inorganic compound that occurs naturally in all surface and groundwater, although higher concentrations tend to occur only where fertilizers are used on the land. The regulatory limit for nitrate in public drinking water supplies was set to protect against infant methemoglobinemia, but other health effects were not considered. Risk of specific cancers and congenital disabilities may be increased when the nitrate is ingested, and nitrate is reduced to nitrite, which can react with amines and amides by nitrosation to form N-nitroso compounds which are known animal carcinogens. This study aims to evaluate the association between nitrate ingested through drinking water and the risk of developing cancers in humans. Methods We performed a systematic review following PRISMA and MOOSE guidelines. A literature search was performed using PubMed, EMBASE, the Cochrane Library databases, Web of Science and Google Scholars in the time-frame from their inception to January 2020, for potentially eligible publications. STATA version 12.0 was used to conduct meta-regression and a two-stage meta-analysis. Results A total of 48 articles with 13 different cancer sites were used for analysis. The meta-regression analysis showed stomach cancer had an association with the median dosage of nitrate from drinking water (t = 3.98, p = 0.0001, and adjusted R-squared = 50.61%), other types of cancers didn’t show any association. The first stage of meta-analysis showed there was an association only between the risk of brain cancer & glioma (OR = 1.15, 95% CI: 1.06, 1.24) and colon cancer (OR = 1.11, 95% CI: 1.04, 1.17) and nitrate consumption in the analysis comparing the highest ORs versus the lowest. The 2nd stage showed there was an association only between the risk colon cancer (OR = 1.14, 95% CI: 1.04, 1.23) and nitrate consumption in the analysis comparing all combined higher ORs versus the lowest. Conclusion This study showed that there is an association between the intake of nitrate from drinking water and a type of cancer in humans. The effective way of controlling nitrate concentrations in drinking water is the prevention of contamination (water pollution). Further research work on this topic is needed.

Maternal Nitrate and Nitrite Intakes during Pregnancy and Risk of Islet Autoimmunity and Type 1 Diabetes: The DIPP Cohort Study

High dietary intake of nitrate and nitrite might increase the risk of type 1 diabetes. To our knowledge, no earlier prospective study has explored whether maternal dietary intake of nitrate and nitrite during pregnancy is associated with the risk of type 1 diabetes in the offspring. Our aim was to study association between maternal intake of nitrate and nitrite during pregnancy and the risk of islet autoimmunity and type 1 diabetes in the offspring. Children born between 1997 and 2004 at Oulu and Tampere University Hospitals in Finland and carrying increased human leukocyte antigen (HLA)-conferred risk for type 1 diabetes were followed in the Type 1 Diabetes Prediction and Prevention (DIPP) study from 3 mo of age. Islet autoantibodies were screened at 3- to 12-mo intervals from serum samples. Of 4879 children, 312 developed islet autoimmunity and 178 developed type 1 diabetes during a 15-y follow-up. Maternal intake of nitrate and nitrite during the eighth month of pregnancy was assessed after birth using a validated self-administered FFQ. Cox proportional hazards regression was used for the statistical analyses. Maternal intake of nitrate and nitrite during pregnancy was not associated with the child's risk of islet autoimmunity [nitrate: HR 0.99 (95% CI: 0.88, 1.11); nitrite: HR 1.03 (95% CI: 0.92, 1.15)] or type 1 diabetes [nitrate: HR 1.02 (95% CI: 0.88, 1.17); nitrite: HR 0.97 (95% CI: 0.83, 1.12)] when adjusted for energy (residual method), sex, HLA risk group, and family history of diabetes. Further adjustment for dietary antioxidants (vitamin C, vitamin E, and selenium) did not change the results. Maternal dietary intake of nitrate or nitrite during pregnancy is not associated with the risk of islet autoimmunity or type 1 diabetes in the offspring genetically at risk for type 1 diabetes.

Ingestion of nitrate and nitrite from drinking water and diet and cancers of the gastrointestinal tract in Iowa women

Background: Nitrate and nitrite are precursors in the endogenous formation of N-nitroso compounds (NOC), potent animal carcinogens in the gastrointestinal tract. Methods: We evaluated nitrate ingestion from public drinking water supplies (PWS), private well use, and dietary nitrate and nitrite intakes in relation to incidence (through 2014) of cancers of the esophagus (n=37), stomach (97), small intestine (47), liver (56), and gallbladder (66) in the Iowa Women’s Health Study (42,000 women ages 50-75 in 1986). Historical nitrate measurements from PWS were linked to the enrollment address by duration. We computed average concentrations and number of years &gt;5 mg/L NO3-N (½ the maximum contaminant level [MCL]). Dietary nitrate and nitrite were estimated using a food frequency questionnaire. We used Cox proportional hazards models to compute hazard ratios (HR) and 95% confidence intervals (CI). Results: In adjusted models, liver cancer risk was elevated among private well users (HR=2.5, CI 0.8-8.5) and those with any years &gt;5 mg/L NO3-N (HR=2.0, CI 0.8-4.9); there was no association with average concentrations (HRper1mg/L NO3-N =1.1, CI 0.7-1.7). Private well use and PWS nitrate concentrations were not associated with other cancers. Dietary nitrate and nitrite from plants was inversely associated with small intestine (HRQ4vsQ1=0.4, CI 0.1-0.9) and gall bladder cancer (HRQ4vsQ1=0.3, CI 0.1-0.8), respectively; there were no associations for the other cancers. Nitrite intake from processed meats was associated with increased risk of stomach (HRnitriteQ4vsQ1=1.7, CI 1.0-3.0) and elevated risk of liver cancer (HRnitriteQ4vsQ1=1.8, CI 0.8-4.0) but was inversely associated with small intestine cancer (HRnitriteQ4vsQ1=0.4, CI 0.1-1.0). Power was limited, but there was no evidence for effect modification by vitamin C and red meat, factors affecting nitrosation. Conclusion: We found novel suggestive evidence that private well use and PWS nitrate may increase liver cancer risk. These associations should be evaluated in studies with larger case numbers.

Easy removal of nitrate and phosphate anions from water by low cost chitosan and activated charcoal

AbstractPresence of nitrate and phosphate ions is difficult to remove from the lakes, as they are highly soluble in water. A way of chemical method adopted to remove these ions from the drinking water using the simple method use of naturally abundant chitosan with charcoal. Adsorption of nitrate and phosphate anions from aqueous solution (water/waste water) on both the chitosan and activated charcoal was investigated. In batch mode adsorption study leads to developing efficient low-cost removal method is important to protect the aquatic environment from the high concentration of nitrate and phosphate anions intake as well as adverse effects on human health. The modified chitosan microspheres had a laudable performance for nitrate and phosphate adsorption Use of this material as an adsorbent is a cheaper and biocompatible method. A systematic study of the adsorption of nitrate and phosphate anions on chitosan and activated charcoal was performed by varying the pH, the initial concentration, contact time, and adsorbent dosage. The results demonstrate that the adsorption process was followed adsorption kinetics of both first and second order kinetics when we use of the chitosan and activated charcoal and chitosan is promising for treating water that is contaminated with nitrate and phosphate anions.

Groundwater quality and non-carcinogenic health risk assessment of nitrate in the semi-arid region of Punjab, India

Groundwater is the main source of water in the study area (Rupnagar District, Punjab), and its quality is essential since it is the primary determinant of the suitability of groundwater for drinking and irrigation purposes. In this study, data from 28 years have been used to evaluate the adequacy of groundwater for domestic and irrigation purposes and assess the potential human health impacts of nitrate contaminants. Results of sodium adsorption ratio, percentage sodium, magnesium hazard ratio, Kelley ratio, and residual sodium carbonate illustrate that most of the sampling locations were suitable for irrigational purposes and drinking water quality of the region mostly belonged to the 'good' class. The maximum nitrate concentration was observed in the northern and north-east parts of the area. Among the three age groups, children > female > male was found to be more prone to health risks with oral ingestion of nitrate. Uncertainties in the risk estimates were quantified using Monte Carlo simulation and sensitivity analyses. Thus, a proper management plan should be adopted by the decision-makers to improve the quality of drinking water in this area to avoid major health problems in the near future.

Evaluation of nitrate contents in regulated and non-regulated leafy vegetables of high consumption in the Canary Islands, Spain: Risk assessment

The nitrate content of the most consumed green leafy vegetables in the European Region of the Canary Islands was determined. The sampling included chard and watercress, which are not regulated but highly consumed in this region. The levels of nitrates in organic vegetables were significantly higher than those of conventional cultivation. However, no seasonal differences were observed, and overall nitrate levels were lower than those reported in other studies. Median nitrate levels in the analyzed vegetables were: lettuce (3 varieties) = 573.7 mg/kg; ready-to-eat salad mixes = 595.0 mg/kg; spinach = 1044.2 mg/kg; arugula = 3144.2 mg/kg; watercress = 450.5 mg/kg; and chard = 1788.4 mg/kg. In general, the nitrate levels of watercress and chard were significantly higher than those of regulated vegetables with similar culinary uses. The average per capita daily intake of nitrates through regulated vegetables was 17.5–32.5% of acceptable daily intake (ADI). On the contrary, the consumption of unregulated vegetables in this archipelago represents a similar, or even higher, percentage of ADI (23.6–44.3%). We, therefore, consider that the establishment of maximum limits of nitrate by the EU regulatory authorities would be appropriate for chard and watercress and similar to those set for spinach.

Efficiency of nitrate oxide donor Tivortin in women with post-infarction cardiosclerosis in the perimenopausal period with heart failure

Objective. To study the effectiveness of the effect of L-arginine in women in the perimenopausal period with post-infarction cardiosclerosis with manifestations of heart failure.&#x0D; Materials and methods. The study included 135 women who were hospitalized at the age from 45 to 60 years. All patients were divided into two groups: group I consisted of 80 women (mean age ‒ 45.1±6.6 years) in the perimenopausal period; group II included 55 women (mean age ‒ 60.6±4.6 years) in the postmenopausal period. The functional state of the heart was investigated by the echo-Doppler method. Treatment and observation continued for 3 months. To identify the effectiveness of the therapy was assessed by monthly echo-Doppler sonography. The first group, against the background of basic therapy (nitrates, β-blockers, antiplatelet agents, statins), additionally received the drug L-arginine 4.2 % (Tivortin) solution of 100 ml intravenously drip for 7-8 days, followed by 5 ml (1 g) 3 times per day inside within 3 months. The second group received only the main therapy without the use of L-arginine.&#x0D; Results. When conducting a comparative assessment of the structural and functional indicators of the heart in women of the first group, it showed that against the background of the main therapy when receiving the drug L-arginine 4.2 % solution 100 ml intravenously before and after treatment were as follows: left atrium size ‒ 5.13±0.18 up to, 4.61±0.14 after; the size of the right ventricle ‒ 3.11±0.01 up to, 2.90±0.08 after; thickness of the interventricular septum ‒ 1.42±0.05 up to, 1.34±0.04 after; posterior wall thickness of left ventricle ‒ 1.38±0.04 up to, 1.34±0.04 after; index of left ventricle myocardial mass ‒ 127.0±5.4 up to, 112.0±4.7 after; end diastolic volume ‒ 144±0.80 up to, 122.0±6.4 after; minute volume ‒ 4.36±0.20 up to, 5.30±0.20 after; ejection fraction ‒ 48 % up to, 52 % after; stroke volume ‒ 54 ml up to, 62 ml after. Clinically noted an increase in exercise tolerance, a decrease in the frequency of nitrate intake and an improvement in the quality of life.&#x0D; Conclusions. In women of group 1, against the background of basic therapy with the addition of L-arginine 4.2 %, the functional class of heart failure decreases from II to I, the indicators of diastolic filling of the left ventricle are normalized, and the incidence of repeated myocardial infarction decreases.

Groundwater chemistry and health risks associated with nitrate intake in Hailun, northeast China.

In order to quantify the hydrochemical characteristics of groundwater in Hailun, analyze the hydrochemical process, and evaluate its health risks associated with nitrate intake, 77 shallow groundwater samples were collected and analyzed. The results show that groundwater in the study area is weakly acidic and groundwater chemical type was dominated by HCO3-Ca, HCO3•Cl-Ca, HCO3-Ca•Na and HCO3•Cl-Ca•Na. Rock weathering and dissolution, ion exchange, and human activities are the main reasons affecting the chemical composition of shallow groundwater in Hailun. The weathering and dissolution process of silicate under weakly alkaline conditions is the source of Na. The dissolution of calcite, dolomite, and gypsum are the main form of water-rock interaction. Results of health risk assessment show that the HQ value for adult males, adult females, children, and infants were in range of 0-1.52, 0-1.75, 0-3.58 and 0-6.08, respectively, and with a mean value of 0.19, 0.22, 0.44, 0.75, respectively. The harm of NO3 pollution is in the order of infant > child > adult female > adult male. The results of this study made local governments pay attention to drinking water safety issues for local residents.

Spleen contraction and Hb elevation after dietary nitrate intake.

Ingestion of dietary nitrate ([Formula: see text]) is associated with improved exercise tolerance and reduced oxygen (O2) cost of exercise, ascribed to enhanced mitochondrial efficiency, muscle contractile function, or other factors. Nitrate ingestion has also been found to attenuate the reduction in arterial oxygen saturation ([Formula: see text]) during apnea and to prolong apneic duration. The spleen serves as a dynamic blood pool expelling erythrocytes into the circulation during apnea, and [Formula: see text] and nitric oxide donors may induce vasoactive effects in the mesenteric and splanchnic circulation. Our aim was to investigate the effect of ingestion of concentrated organic [Formula: see text]-rich beetroot juice (BR) on spleen volume and spleen contraction during apnea, and the resulting hemoglobin (Hb) concentration. Eight volunteers performed two apneas of submaximal and maximal duration during prone rest ∼2.5 h after ingesting 70 mL of BR (∼5 mmol [Formula: see text]) or placebo (PL; ∼0.003 mmol [Formula: see text]), on separate days in weighted order. Heart rate and [Formula: see text] were monitored continuously and spleen diameters were measured every minute for triaxial volume calculation. Capillary Hb samples were collected at baseline and after the maximal apnea. Baseline spleen volume was reduced by 66 mL after BR ingestion (22.9%; P = 0.026) and Hb was elevated (+3.0%; P = 0.015). During apneas, spleen contraction and Hb increase were similar between BR and PL conditions (NS). The study shows that dietary [Formula: see text]reduces spleen volume at rest, resulting in increased Hb. This spleen-induced Hb elevation following [Formula: see text] ingestions represents a novel mechanism that could enhance performance in conditions involving exercise, apnea, and hypoxia.NEW & NOTEWORTHY This is the first study to examine changes of spleen volume and circulating Hb following dietary [Formula: see text] supplementation. After dietary [Formula: see text] ingestion, the spleen volume at rest was reduced and Hb was elevated. The spleen contains a dynamic red blood cell reservoir, which can be mobilized and facilitate oxygen transport during various types of physiological stress. This study has revealed an additional, previously unexplored mechanism possibly contributing to the ergogenic effects of dietary [Formula: see text].

Effects of Dietary Nitrates on Time Trial Performance in Athletes with Different Training Status: Systematic Review.

Much research has been done in sports nutrition in recent years as the demand for performance-enhancing substances increases. Higher intake of nitrates from the diet can increase the bioavailability of nitric oxide (NO) via the nitrate–nitrite–NO pathway. Nevertheless, the increased availability of NO does not always lead to improved performance in some individuals. This review aims to evaluate the relationship between the athlete’s training status and the change in time trial performance after increased dietary nitrate intake. Articles indexed by Scopus and PubMed published from 2015 to 2019 were reviewed. Thirteen articles met the eligibility criteria: clinical trial studies on healthy participants with different training status (according to VO2max), conducting time trial tests after dietary nitrate supplementation. The PRISMA guidelines were followed to process the review. We found a statistically significant relationship between VO2max and ergogenicity in time trial performance using one-way ANOVA (p = 0.001) in less-trained athletes (VO2 < 55 mL/kg/min). A strong positive correlation was observed in experimental situations using a chronic supplementation protocol but not in acute protocol situations. In the context of our results and recent histological observations of muscle fibres, there might be a fibre-type specific role in nitric oxide production and, therefore, supplement of ergogenicity.

Probabilistic risk assessment of nitrates for Austrian adults and estimation of the magnitude of their conversion into nitrites

Nitrates occur in food naturally, as contaminants or additives. The health implications attributed to ingested nitrates result primarily from their conversion into nitrites and subsequent methemoglobinemia, carcinogenicity induced by N-nitroso-compounds and cardiovascular, endocrine, metabolic, reproductive and developmental effects. The present study comprises a probabilistic tiered risk assessment of nitrates for Austrian adults through the diet with the application of the Monte Carlo simulation method in alternative optimistic and pessimistic scenarios. Risk estimates are of concern regarding the upper exposures, which exceed the Acceptable Daily Intake (ADI) in almost all scenarios and population groups. Exposure is elevated when all dietary sources are considered and the ADI is exceeded by already the mean intake for vegetarians. Leafy vegetables are major contributors to the intake. Contribution of cured meat is very low. Estimates of the conversion of nitrates into nitrites were used to assess the combined exposure to both species. When the average intake of nitrates and nitrites is considered, the mean exposure to nitrites is lower or close to the ADI for individuals with average conversion capacity. However, upper tail combined intake can lead to a multifold exceedance of the ADI of nitrites for individuals with both high and average conversion capacity.

Whole beetroot consumption reduces systolic blood pressure and modulates diversity and composition of the gut microbiota in older participants

BackgroundAge-associated decline in physiological function has been identified as the main factor increasing disease risk, including cardiovascular (CVD) and gastrointestinal tract (GIT) diseases. Nutritional interventions encompassing dietary inorganic nitrates, such as nitrate rich beetroot may reduce the risk for CVD and GIT. ObjectiveAssess the impact of whole beetroot on blood pressure (BP), microbiota profile and functional measures (physical and bowel). DesignThirty-six healthy participants were recruited (mean age 67 ± 6 years; body mass index (BMI) 25 ± 2 kg/m2) and assigned randomly to a beetroot (n = 19) or control group (n = 17). Beetroot group consumed 150 g of whole beetroot and a medium-sized banana and the control group consumed a medium-sized banana every second day for 8 weeks. Resting BP, microbiota profiling, physical activity, urinary nitrate, short-chain fatty acids (SCFA) and Bristol Stool Score (BSS) were measured at 0, 4 and 8 weeks. Plasma nitrate was measured at weeks 0 and 8. ResultsThe beetroot group had a resting systolic BP reduction of 8.0 mmHg (p = 0.03), lower relative abundance of the phyla Bacteroidetes (p = 0.04), and a higher relative abundance of genus Alistipes (p = 0.03), increased Shannon diversity index (p = 0.03), fibre intake of 7 g/day (p < 0.01), nitrate intake 145 mg/day (p < 0.01), urinary nitrate of 460 μmol/L (p = 0.02) and SCFA concentrations (p < 0.05). However, 8 weeks of beetroot consumption did not have any impact upon functional measures, urine or plasma nitrate and BSS. ConclusionIn a randomised controlled trial, consuming whole beetroot for 8 weeks resulted in modification of risk factors for CVD and GIT disorders in older participants. Physical measures were unaffected and further assessment of more sensitive measures of functional performance are required to ascertain if whole beetroot may offer additional physiological benefits in older populations. Although the data here is promising, further mechanistic studies and larger clinical trials are required to confirm the findings.

Dietary intake and health risk assessment of nitrate, nitrite, and nitrosamines: a Bayesian analysis and Monte Carlo simulation.

Nitrate, nitrite, and nitrosamines intake from the diet creates human health risks. In this study, nitrate/nitrite intake from diet and its association with nitric oxide (NO) level in humans have been surveyed. Besides nitrate/nitrite, nitrosamines risks were also determined from the diet. This study was conducted as a pilot study; 33 heathy adults participated in and completed the Food Frequency Questionnaire (FFQ) for 3days. Then, concentrations of nitrate, nitrite, and nitrosamines were studied by the literature review. Also, the association between the intake of nitrate and nitrite with salivary and urinary NO was evaluated by Bayesian bi-variate analysis. Then, the health risk was assessed for nitrate/nitrite from food groups and drinking water, and nitrosamines from food groups based on hazard index (HI) and cancer risk with the Monte Carlo simulation. The nitrate/nitrite intakes had no association with NO level in the saliva and urine samples. The mean of HI value for the mean of 3days was 3.57 and 0.32 from food groups and drinking water, respectively. The cancer risk amount of nitrosamines from food groups was (1.74 to 2.22) × 10-3 based on 95% confidence interval (CI 95%) values. This study showed the Iranian diet had a high risk, but drinking water consumption was safe based on nitrate/nitrite and nitrosamines for humans. There is a need to determine the concentration of nitrosamines in drinking water in Iran and to recommend for decrease risk of nitrate, nitrite, and nitrosamines exposure by food groups.

Oral Administration of Sodium Nitrate to Metabolic Syndrome Patients Attenuates Mild Inflammatory and Oxidative Responses to Acute Exercise.

The beneficial effects of exercise for the treatment and prevention of metabolic syndrome pathologies have been related to its anti-inflammatory and antioxidant effects. Dietary nitrate supplementation is an emerging treatment strategy to alleviate the symptoms of metabolic syndrome affections and to improve vascular function. In this double-blind crossover trial, metabolic syndrome patients performed two exercise tests for 30 min at 60–70% maximal heart rate after the intake of a placebo or a nitrate-enriched beverage. Acute exercise increased the plasma concentration of TNFα, intercellular adhesion molecule ICAM1, PGE1, PGE2 and the newly detected 16-hydroxypalmitic acid (16-HPAL) in metabolic syndrome patients. The cytokine and oxylipin production by peripheral blood mononuclear cells (PBMCs) and neutrophils could be responsible for the plasma concentrations of TNFα and IL6, but not for the plasma concentration of oxylipins nor its post-exercise increase. The intake of sodium nitrate 30 min before exercise increased the concentration of nitrate and nitrite in the oral cavity and plasma and reduced the oxygen cost of exercise. Additionally, nitrate intake prevented the enhancing effects of acute exercise on the plasma concentration of TNFα, ICAM1, PGE1, PGE2 and 16-HPAL, while reducing the capabilities of PBMCs and neutrophils to produce oxylipins.

Daily intake of nitrate and nitrite via meat and poultry in Egypt

ABSTRACT Nitrate and nitrite are the most applied food additives to inhibit microbial growth. The main risk of nitrate and nitrite presence in food is the formation of nitrosamines during food preparation and digestion. However, dietary intake of nitrite and nitrate from food has potential cardiovascular benefits. Accordingly, 160 samples from meat and poultry were randomly collected to evaluate the level of occurrence nitrate and nitrite using an HPLC method and estimate the daily intake (EDI) of Egyptian adults and children. The levels of nitrate and nitrite ranged between 1.3–557 mg/kg and 6–812 mg/kg, respectively. The EDI was compared with the accepted daily intake (ADI) represented in the hazard index (HI) scale. The nitrite results clarify that all HI values were above 1 for all commodities, while for nitrate it exceeded 1 only for canned meat and basturma, when consumed by children.

Abstract PR04: Exposure-based assessment and economic valuation of adverse birth outcomes and cancer risk due to nitrate in United States drinking water

Abstract Background: Nitrate ingestion from drinking water has been associated with an increased risk of adverse birth outcomes as well as elevated risk of colorectal cancer and several other cancers. Yet, to date no studies have attempted to quantify the health and economic impacts due to nitrate in drinking water in the United States. Methods: This study presents a first-of-its-kind comprehensive assessment of nitrate exposure from drinking water for the entire United States population. This exposure assessment serves as the basis for our analysis of the annual nitrate-attributable disease cases in the United States and the associated economic losses due to medical costs and lost productivity. Additionally, through a meta-analysis of studies on drinking water nitrate and colorectal cancer, we examine the exposure-response relationship for nitrate and cancer risk. Results: On the basis of national nitrate occurrence data and relative risk ratios reported in the epidemiology literature, we calculated that annually, 2,939 cases of very low birth weight, 1,725 cases of very preterm birth, and 41 cases of neural tube defects could be related to nitrate exposure from drinking water. For cancer risk, combining nitrate-specific risk estimates for colorectal, ovarian, thyroid, kidney, and bladder cancers results in a range of 2,300 to 12,594 annual nitrate-attributable cancer cases (mean: 6,537 estimated cases). For medical expenditures alone, this burden of cancer corresponds to an annual economic cost of $250 million to $1.5 billion U.S. dollars, together with a potential $1.3 to $6.5 billion impact due to lost productivity. With the meta-analysis of eight studies of drinking water nitrate and colorectal cancer, we observed a statistically significant positive association for nitrate exposure and colorectal cancer risk and calculated a one-in-one million cancer risk level of 0.14 mg/L nitrate in drinking water. Conclusion: Health and economic analyses presented here suggest that lowering exposure to nitrate in drinking water could bring economic benefits by alleviating the impacts of nitrate-associated diseases. This abstract is also being presented as Poster A44. Citation Format: Alexis Temkin, Sydney Evans, Tatiana Manidis, Chris Campbell, Olga V. Naidenko. Exposure-based assessment and economic valuation of adverse birth outcomes and cancer risk due to nitrate in United States drinking water [abstract]. In: Proceedings of the AACR Special Conference on Environmental Carcinogenesis: Potential Pathway to Cancer Prevention; 2019 Jun 22-24; Charlotte, NC. Philadelphia (PA): AACR; Can Prev Res 2020;13(7 Suppl): Abstract nr PR04.

Dietary Nitrate Intake Improves Vascular Function And Walking Capacity In Patients With Peripheral Artery Disease

Peripheral artery disease (PAD) is the manifestation of atherosclerosis in the arteries of the legs, which reduces blood flow to the lower extremities and impairs walking capacity. Dietary nitrate has been used to reduce blood pressure (BP) and increase exercise tolerance in PAD. However, a standard dose, body mass normalized nitrate, for PAD has yet to be determined. PURPOSE: To elucidate the impacts of a body mass-normalized dose of nitrate (0.11 mmol nitrate/kg) in the form of beetroot juice on resting heart rate (RHR), central and peripheral BP, vascular function, and exercise tolerance in patients with PAD. METHODS: In a randomized crossover design, 10 patients with PAD (stage II-III) received either the nitrate supplement or placebo. At each visit, measures of RHR, central and peripheral BP, brachial and popliteal artery endothelial function (flow-mediated dilation, FMD), arterial stiffness (pulse-wave velocity, PWV), augmentation index (AIx)), maximal walking capacity, and time to claudication (COT) were measured before and after nitrate and placebo. RESULTS: There were significant group by time interactions (p<0.05) for systolic BP, endothelial function, and maximal walking distance. Systolic BP was significantly reduced (p<0.05) while popliteal FMD, brachial FMD, and maximal walking time significantly increased (p<0.05). Nitrate intake reduced central systolic BP and increased maximal walking time (p<0.05). There were trends for decreased diastolic BP (p=0.15), central diastolic BP (p=0.06), and central pulse pressure (p=0.17). There were no changes in RHR, deceleration time, max dP/dt, carotid-to-radial PWV, carotid-to-femoral PWV, carotid-to-ankle PWV, AIx, or COT (p>0.05). CONCLUSIONS: These results indicate that a dose of nitrate (~0.11 mmol nitrate/kg) seems to be an effective dose for improving BP, vascular function, and walking capacity in patients with PAD.

Vegetables with High-Nitrate Content Significantly Increase Plasma Nitrate and Nitrite Concentrations but Do Not Significantly Reduce Systolic Blood Pressure in Young Healthy Men

Aims: To investigate the effects of supplementation with high-nitrate and low-nitrate vegetables on plasma nitrate and nitrite concentrations, blood pressure and the oxygen demand of moderate-intensity exercise.&#x0D; Study Design: A randomized, cross-over design.&#x0D; Place and Duration of Study: Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, between January 2011 and March 2012.&#x0D; Methodology: 15 non-smoking, physically active healthy men (age 25 ± 6 years, BMI 24 ± 4 kg/m2) were randomized to receive a 2-week supply of high-nitrate or low-nitrate vegetables, with a 2-week ‘wash-out’ period in between. Clinic blood pressure, plasma nitrate and nitrite concentrations and physiological responses to moderate-intensity exercise tests were measured before and after each 2-week intervention. Nitrate intake was calculated using nutritional analysis of reported vegetables consumed.&#x0D; Results: Participants consumed significantly more dietary nitrate on the high-nitrate diet (417 ± 139 mg/day) than the low-nitrate diet (26 ± 11 mg/day). The high-nitrate diet supplied 5.5 mg nitrate/kg body weight, exceeding the Acceptable Daily Intake (ADI) of 3.7 mg nitrate/kg body weight. Supplementation with high-nitrate vegetables significantly increased plasma nitrate concentrations (baseline; 30 ± 20 µM, after high-nitrate vegetables; 129 ± 87 µM) and plasma nitrite concentrations (baseline; 119 ± 35 nM, after high-nitrate vegetables; 227 ± 89 nM) but did not significantly change systolic blood pressure or the physiological response to moderate exercise. There were significant correlations between diastolic blood pressure and plasma nitrite concentrations (low-nitrate diet; r = 0.63, high-nitrate diet, r = 0.56).&#x0D; Conclusion: Supplementation with high-nitrate vegetables above the ADI significantly increased plasma nitrate and nitrate concentrations but did not significantly reduce systolic blood pressure or the physiological response to moderate exercise. Plasma nitrite concentrations significantly correlated with diastolic blood pressure after high-nitrate and low-nitrate diets.