Dietary nitrate and nitrite and human health: a narrative review by intake source

Dietary Exposure to Food Contaminants of Pregnant Women in Northern Spain and Possible Effects on Fetal Anthropometric Parameters

A considerable number of organizations are working to improve food safety, with particular attention to vulnerable groups such as pregnant women due to the important influence of diet on fetal development. The aim of this study was to evaluate exposure to 11 food processing contaminants and their effects on maternal and fetal health. Online questionnaires during the first and third trimesters were used to analyze the intake and exposure to different food contaminants, estimated from the contaminants food database "CONT11", in 84 pregnant women in Oviedo (Spain) and their influence on newborn anthropometric data. Exposure to certain contaminants, such as acrylamide or total polycyclic aromatic hydrocarbons, was found to have a significant impact on maternal and fetal health, particularly in relation to birth weight or head circumference. During the third trimester, pregnant women reported dietary improvement and reduced exposure to dietary contaminants. Identifying the foods and food groups that contribute most to exposure and the potential for health professionals will facilitate the development of basic exposure reduction strategies. This study is one of the few to assess the exposure of pregnant women to a wide range of contaminants and their impact on fetal health, providing a baseline for future research.

In vitro colonic fermentation of clean label ham formulations: Gut microbiota modulation and metabolite production

Consumer wishes for "clean label" products have prompted the rise of these products available in the market. With dietary choices directly influencing market trends, developing novel meat products with natural nitrate and nitrite alternatives is a sought-after premise. Cured meats like ham have been under scrutiny due to their potential harm to human health, having sodium nitrite been theorised to trigger dysbiosis of the gut microbiota and impair faecal short-chain fatty acids (SCFAs) production. Four novel ham formulations with a natural nitrate source coupled with nitrate-reducing starter cultures were subjected to an in vitro gastrointestinal digestion simulation (INFOGEST) and followed by in vitro colonic fermentation. The impact of each novel ham formulation on the gut microbiota and their fermentation metabolites, namely SCFAs, was assessed by quantitative Next Generation Sequencing and High-Performance Liquid Chromatography, respectively. No significant differences have been found for SCFAs levels or microbial communities throughout colonic fermentation. Further research should provide insight into how these alternatives can be associated with nitrosamine formation. The potential benefits of "clean label" alternatives need to be thoroughly demonstrated. While these solutions are often considered preferable to traditional nitrite-containing products, their implementation should be approached with caution. In addition to their antimicrobial efficacy and consumer acceptance, it is essential to assess their impact on product cost and compare their performance and health impact (positive or negative) with that of traditional nitrite formulations. Extensive research is needed to ensure that any move to "clean label" formulations is based on solid evidence rather than market trends.

Overview of foodborne hazards associated with inflammation and metabolic health

Access to safe and nutritious food is key to ensuring health and well-being and is critical to meeting the United Nations' Sustainable Development Goals. However, a synthesis of the associations between foodborne illness and malnutrition, such as metabolic health, remains a gap in the literature base. In this review, we summarized existing evidence on the impacts of biological and chemical hazards on nutrition-related health outcomes, specifically overweight and obesity, inflammation, metabolic disease, thyroid function, cancer development, and adverse birth outcomes, examining physiological mechanisms, epidemiological associations, and animal studies. Mechanisms between some foodborne hazards, such as H. pylori, and adverse pregnancy outcomes, e.g., gestational diabetes mellitus, or between nitrates and impaired thyroid function, are relatively well-studied. However, evidence on the effects of many other chemical hazards on metabolic and human health remains limited: for example, while arsenic exposure is associated with adverse birth outcomes, the limited availability of dose-response studies and other challenges limit ascertaining its causal role. Untangling these associations and physiological mechanisms is of high relevance for both high- as well as low- and middle-income countries. Emerging technologies and novel assessment techniques are needed to improve the detection and understanding of understudied and complex foodborne diseases, particularly those arising from chemical hazards. These evidence gaps are highlighted in this review, as well as the need for establishing surveillance systems for monitoring foodborne diseases and metabolic health outcomes across populations.

Associations Between Metals and Nonmetals in Drinking Water, Cardiovascular Events, and Diet

BACKGROUND

Metals and nonmetals in drinking water could potentially influence cardiovascular health. The relationship between poor-quality drinking water, major adverse cardiovascular events (MACE), and diet is not well studied.

OBJECTIVES

The aim of this study was to determine whether long-term exposure to metals (copper, manganese, aluminum, zinc, and cadmium) and nonmetals (selenium, sulfate, and nitrate-nitrogen) in drinking water was associated with MACE outcomes, and whether the dietary patterns could modify the association between long-term exposure to low-quality drinking water and MACE.

METHODS

Data from a prospective population-based cohort from Yinzhou District, Ningbo (follow-up between 2016 and 2022) were linked to Yinzhou Health Information System. MACE endpoints included acute myocardial infarction (AMI), heart failure, stroke, angina, and cardiovascular death. Effect modification of the associations between exposure and MACE by dietary factors was determined.

RESULTS

In the final cohort of 24,212 participants, 57 had an AMI; 886 developed heart failure; 733 had a stroke; 23 had angina; and 134 had a cardiovascular death. An increased risk of: 1) AMI was seen with exposure to copper, aluminum, cadmium, and selenium; 2) stroke with exposure to zinc, copper, and selenium; 3) angina with exposure to zinc and copper; and 4) cardiovascular death with exposure to zinc and aluminum in drinking water. Consuming fish, white meat, and grain products attenuated MACE outcomes induced by metals and nonmetals in drinking water.

CONCLUSIONS

In this study, long-term exposure to higher metallic and nonmetallic elements in drinking water was associated with an increased risk of MACE. Specific dietary patterns modified the associations. Further studies are needed in this area.

In utero and early-life nitrate in drinking water impacts lung function of weanling rats

Consumption of nitrate in drinking water has previously been associated with a range of adverse health effects, including methemoglobinemia and potentially cancer. In animal models, it has been shown to impact respiratory structure and function, however, there is a paucity of data of the effects of in utero exposure on the respiratory health of offspring. In this study, pregnant rats were given drinking water containing nitrate at 50 or 100 mg/L (or control). At three weeks of age, we assessed a range of respiratory health outcomes, including lung function, pulmonary inflammation and lung structure, in the offspring of both sexes. Nitrate exposure was associated with minor adverse effects on lung function, including an increase in airway resistance at functional residual capacity in male offspring, but there were no significant changes in lung structure. Our results suggest that in utero / early-life exposure to nitrates in drinking water at levels relevant to human exposure is unlikely to have significant negative impacts on offspring respiratory health.

Exploring the wound healing potential of dietary nitrate in diabetic rat model

Introduction

The wound healing in diabetes is hindered and prolonged due to long-term inflammation, oxidative stress damage, and angiogenesis disorders induced by high glucose status. The management of such difficult-to-treat wounds continues to pose a significant challenge in clinical treatment. Dietary nitrate, commonly found in greens such as beets and spinach, acts as a nutritional supplement and is metabolized in the body through the salivary nitrate-nitrite-NO pathway. This pathway plays a crucial role in various physiological functions, including enhancing blood flow and attenuating inflammation.

Methods

In this study, we established a diabetic rat wound model. Forty-eight rats were randomly divided into six groups (n = 8): the Con group, the Con + Nitrate group, the STZ group, the STZ + NaCl group, the STZ + rhEGF group, and the STZ + Nitrate group. Skin wound healing was assessed on the day of surgery and on postoperative days 3, 7, 10, and 14. Specimens were taken on days 7 and 14 post-surgery for relevant tests.

Results

We found that dietary nitrate could accelerate skin wound healing by promoting angiogenesis and increasing blood perfusion. Significantly, dietary nitrate also regulated glucose and lipid metabolism and exhibited anti-inflammatory and antioxidant properties.

Discussion

These findings provide a novel theoretical basis for managing wounds in diabetic individuals, indicating the broad potential of dietary nitrate in future clinical applications.

Enhancing nitrate removal from small wetlands via regulating bacterial-algal symbiosis with macrophyte coverage

With increasing land resource constraints, wetlands, as ecological hotspots, are expected to enhance biogeochemical processes to mitigate nitrogen (N) pollution, particularly nitrate-nitrogen (NO3--N). However, the interactions among bacteria, algae, and macrophytes in wetlands, which are crucial for N removal, remain largely unknown. This study explored how macrophyte coverage influences bacterial-algal interactions, shifting from mutualism to inhibition, thereby affecting N removal. Moderate coverage enhanced NO3--N and total nitrogen (TN) removal (P < 0.05), which was correlated with increased microbial abundance (P < 0.05). This may have resulted from moderate algal photosynthesis, reduced physiological stress, and the expansion of ecological niches for microbes. Insufficient coverage promoted algal growth (chlorophyll-a > 31.8 μg·L-1), leading to increased competition for substrates and elevated pH, which further inhibited bacterial activity. Excessive coverage also inhibited bacterial activity by reducing illumination and oxidation-reduction potential. Consequently, insufficient and excessive coverage decreased N removal efficiencies by 2.7-15.7 % (NO3--N) and 3.7-11.1 % (TN) while increasing methane emission potential by 1.4-6.9 times compared with moderate coverage. These findings offer insights into solving NO3--N contamination using near-natural methods and balancing the ecological and practical considerations for small wetlands.

Nicotinamide Alleviates Synergistic Impairment of Intestinal Barrier Caused by MC-LR and NaNO2 Coexposure

Microcystin-LR (MC-LR) and nitrites from the environment and daily life can be ingested and absorbed by humans via the digestive tract. However, their combined effects on intestinal health remain unclear. Here, the combined impact of MC-LR and sodium nitrite (NaNO2) on the intestines of mice was investigated under actual human exposure conditions. After mice were exposed to MC-LR (10, 100 μg/L) and NaNO2 (30, 300 mg/L) individual and in combination for 6 months, it was found that MC-LR and NaNO2 synergistically decreased intestinal permeability and disrupted intestinal physical, chemical, immune, and microbial barriers. In the coexposure groups, the synergistic impairment to the intestinal barrier was noted with increasing concentrations of MC-LR or NaNO2, but this adverse effect was alleviated by nicotinamide supplementation. This study underscores the potential risks of simultaneous ingestion of MC-LR and nitrite on intestinal health. The protective role of nicotinamide suggests avenues for therapeutic intervention against environmental toxin-induced intestinal impairment.

Nitrogen Level Impacts the Dynamic Changes in Nitrogen Metabolism, and Carbohydrate and Anthocyanin Biosynthesis Improves the Kernel Nutritional Quality of Purple Waxy Maize

Waxy corn is a special type of maize primarily consumed as a fresh vegetable by humans. Nitrogen (N) plays an essential role in regulating the growth progression, maturation, yield, and quality of waxy maize. A reasonable N application rate is vital for boosting the accumulation of both N and carbon (C) in the grains, thereby synergistically enhancing the grain quality. However, the impact of varying N levels on the dynamic changes in N metabolism, carbohydrate formation, and anthocyanin synthesis in purple waxy corn kernels, as well as the regulatory relationships among these processes, remains unclear. To explore the effects of varying N application rates on the N metabolism, carbohydrate formation, and anthocyanin synthesis in kernels during grain filling, a two-year field experiment was carried out using the purple waxy maize variety Jinnuo20 (JN20). This study examined the different N levels, specifically 0 (N0), 120 (N1), 240 (N2), and 360 (N3) kg N ha-1. The results of the analysis revealed that, for nearly all traits measured, the N application rate of N2 was the most suitable. Compared to the N0 treatment, the accumulation and content of anthocyanins, total nitrogen, soluble sugars, amylopectin, and C/N ratio in grains increased by an average of 35.62%, 11.49%, 12.84%, 23.74%, 13.00%, and 1.87% under N2 treatment over five filling stages within two years, respectively, while the harmful compound nitrite content only increased by an average of 30.2%. Correspondingly, the activities of related enzymes also significantly increased and were maintained under N2 treatment compared to N0 treatment. Regression and correlation analysis results revealed that the amount of anthocyanin accumulation was highly positively correlated with the activities of phenylalanine ammonia-lyase (PAL) and flavanone 3-hydroxylase (F3H), but negatively correlated with anthocyanidin synthase (ANS) and UDP-glycose: flavonoid-3-O-glycosyltransferase (UFGT) activity, nitrate reductase (NR), and glutamine synthetase (GS) showed significant positive correlations with the total nitrogen content and lysine content, and a significant negative correlation with nitrite, while soluble sugars were negatively with ADP-glucose pyrophosphorylase (AGPase) activity, and amylopectin content was positively correlated with the activities of soluble starch synthase (SSS), starch branching enzyme (SBE), and starch debranching enzyme (SDBE), respectively. Furthermore, there were positive or negative correlations among the detected traits. Hence, a reasonable N application rate improves purple waxy corn kernel nutritional quality by regulating N metabolism, as well as carbohydrate and anthocyanin biosynthesis.

The Association between Food Groups, Nutraceuticals, and Food Supplements Consumption on Vascular Health Outcomes: A Literature Review

Vascular aging, marked by alterations in the structure and function of blood vessels, including heightened arterial stiffness and impaired endothelial function, is linked to a higher likelihood of developing cardiovascular and age-associated pathological conditions. Oxidative stress and inflammation are key stimulation factors in vascular aging. Engaging in healthy dietary habits could enhance the functioning of blood vessels. The aim of this study was to conduct a literature review of the evidence regarding the relationship between food regimens, nutraceuticals, and dietary supplements and vascular health. A search of electronic databases, including PubMed, Scopus, and Web of Science Core Collection, was performed. Experimental and observational studies evaluating the association between food groups, nutraceuticals, supplements, and endothelial function and/or arterial stiffness were deemed eligible for this narrative review. Based on the current body of the included studies, food groups, nutraceuticals, and dietary supplements may not demonstrate superiority over placebos in enhancing markers of vascular health. To obtain more reliable evidence on the effectiveness of interventions in vascular health, additional RCTs with larger sample sizes, extended follow-up periods, and multi-center participation are necessary. Enhancing the credibility of these RCTs requires better control of dietary variables and more precise measurement of vascular health markers.

Nitrate: "the source makes the poison"

Interest in the role of dietary nitrate in human health and disease has grown exponentially in recent years. However, consensus is yet to be reached as to whether consuming nitrate from various food sources is beneficial or harmful to health. Global authorities continue to recommend an acceptable daily intake (ADI) of nitrate of 3.7 mg/kg-bw/day due to concerns over its carcinogenicity. This is despite evidence showing that nitrate consumption from vegetable sources, exceeding the ADI, is associated with decreased cancer prevalence and improvements in cardiovascular, oral, metabolic and neurocognitive health. This review examines the paradox between dietary nitrate and health and disease and highlights the key role of the dietary source and food matrix in moderating this interaction. We present mechanistic and epidemiological evidence to support the notion that consuming vegetable-derived nitrate promotes a beneficial increase in nitric oxide generation and limits toxic N-nitroso compound formation seen with high intakes of nitrate added during food processing or present in contaminated water. We demonstrate the need for a more pragmatic approach to nitrate-related nutritional research and guidelines. Ultimately, we provide an overview of our knowledge in this field to facilitate the various therapeutic applications of dietary nitrate, whilst maintaining population safety.

Tracing the impacts of ecological water replenishment on the sources and transformation of groundwater nitrate through isotope and microbial analysis

Ecological water replenishment (EWR) changes the recharge conditions, flow fields, and physicochemical properties of regional groundwater. However, the resulting impacts on mechanisms regulating the sources and transformation of groundwater nitrate remain unclear. This study investigated how EWR influences the sources and transformation processes of groundwater nitrate using an integrated approach of Water chemistry analysis and stable isotopes (δ15N-NO3- and δ18O-NO3-) along with microbial techniques. The results showed that groundwater NO3-N decreased from 12.98 ± 7.39 mg/L to 7.04 ± 8.52 mg/L after EWR. Water chemistry and isotopic characterization suggested that groundwater nitrate mainly originated from sewage and manure. The Bayesian isotope mixing model (MixSIAR) indicated that EWR increased the average contribution of sewage and manure sources to groundwater nitrate from 46 % to 61 %, whereas that of sources of chemical fertilizer decreased from 43 % to 21 %. Microbial community analysis revealed that EWR resulted in a substantial decrease in the relative abundance of Pseudomonas spp denitrificans, from 13.7 % to 0.6 %. Both water chemistry and microbial analysis indicated that EWR weakened denitrification and enhanced nitrification in groundwater. EWR increases the contribution of nitrate to groundwater by promoting the release of sewage and feces in the unsaturated zone. However, the dilution effect caused by EWR was stronger than the contribution of sewage and fecal sources to groundwater nitrate. As a result, EWR helped to reduce groundwater nitrate concentrations. This study showed the effectiveness of integrated isotope and microbial techniques for delineating the sources and transformations of groundwater nitrate influenced by EWR.

Applications of Plant Bioactive Compounds as Replacers of Synthetic Additives in the Food Industry

According to the Codex Alimentarius, a food additive is any substance that is incorporated into a food solely for technological or organoleptic purposes during the production of that food. Food additives can be of synthetic or natural origin. Several scientific evidence (in vitro studies and epidemiological studies like the controversial Southampton study published in 2007) have pointed out that several synthetic additives may lead to health issues for consumers. In that sense, the actual consumer searches for "Clean Label" foods with ingredient lists clean of coded additives, which are rejected by the actual consumer, highlighting the need to distinguish synthetic and natural codded additives from the ingredient lists. However, this natural approach must focus on an integrated vision of the replacement of chemical substances from the food ingredients, food contact materials (packaging), and their application on the final product. Hence, natural plant alternatives are hereby presented, analyzing their potential success in replacing common synthetic emulsifiers, colorants, flavorings, inhibitors of quality-degrading enzymes, antimicrobials, and antioxidants. In addition, the need for a complete absence of chemical additive migration to the food is approached through the use of plant-origin bioactive compounds (e.g., plant essential oils) incorporated in active packaging.

Mechanism and Association between Microbial Nitrogen Transformation in Rhizosphere and Accumulation of Ciprofloxacin in Choysum (Brassica parachinensis)

Rhizosphere microbiota are an important factor impacting plant uptake of pollutants. However, little is known about how microbial nitrogen (N) transformation in the rhizosphere affects the uptake and accumulation of antibiotics in plants. Here, we determined recruitment of N transformation functional bacteria upon ciprofloxacin (CIP) exposure, by comparing differences in assembly processes of both rhizospheric bacterial communities and N transformation between two choysum (Brassica parachinensis) varieties differing in CIP accumulation. The low accumulation variety (LAV) of CIP recruited more host bacteria (e.g., Nitrospiria and Nitrolancea) carrying nitrification genes (mainly nxrA) but fewer host bacteria carrying denitrification genes, especially narG, relative to the high accumulation variety (HAV) of CIP. The nxrA and narG abundance in the LAV rhizosphere were, respectively, 1.6-7.8 fold higher and 1.4-3.4 fold lower than those in the HAV rhizosphere. Considering that nitrate can decrease CIP uptake into choysum through competing for the proton motive force and energy, such specific bacteria recruitment in LAV favored the production and utilization of nitrate in its rhizosphere, thus limiting its CIP accumulation with 1.6-2.4 fold lower than the HAV. The findings give insight into the mechanism underlying low pollutant accumulation, filling the knowledge gap regarding the profound effects of rhizosphere microflora and N transformation processes on antibiotic accumulation in crops.

Theoretical estimation of nitrates and nitrites intake from food additives by the Brazilian population

Sodium and potassium nitrates and nitrites are preservatives widely used in meat products and some cheese. They are important toxicologically but there is a lack of data on the exposure of the Brazilian population to these additives. This study aimed to verify the frequency of the use of nitrates and nitrites in processed foods in Brazil and to estimate their theoretical intake by the Brazilian population. A database was built of supermarket products containing nitrates, nitrites, and antioxidants. The Theoretical Maximum Daily Intake (TMDI) and TMDI balanced by the prevalence of food consumption (TMDI BPFC) were determined using consumption data from the Household Budget Surveys (2008/2009 and 2017/2018). The TMDI for nitrates and nitrites was lower than the Acceptable Daily Intake (ADI) for all population groups. Considering the prevalence of food consumption (consumers only), the TMDI BPFC values were lower than the ADI for nitrates (between 0.4 and 0.9 times the ADI) but very high values were obtained for nitrites (between 10 and 24 times the ADI). Our results suggest that the Brazilian population, especially some population groups, may be consuming unsafe amounts of nitrite. As a consequence, their health may be at risk.

Nitrite and nitrate intake from processed meat is associated with elevated diastolic blood pressure (DBP)

BACKGROUND AND AIMS

Processed meat consumption has been linked to high blood pressure (BP), a key risk factor for cardiovascular disease (CVD), but gaps remain with regards to the ingredients which contribute to this association. This study, therefore, aimed to examine the association between nitrite and nitrate intake from processed meat with diastolic (DBP) and systolic (SBP) blood pressure, while accounting for sodium intake.

METHODS

Dietary nitrite and nitrate intake from processed meat, assessed as total nitrite equivalent, was estimated for 1774 adult, processed meat consumers (≥18 years, 55.1% females) who had enrolled in the Hellenic National Nutrition and Health Survey (HNNHS). To avoid selection and reverse causality bias, associations with measured DBP and SBP were considered instead of self-reported data of hypertension presence. Participants were divided by tertile of dietary nitrite intake and by level of dietary guideline adherence for sodium (<1500; 1500-2300; ≥2300). Multiple regression models were used to examine associations with SBP and DBP, including an interaction term of nitrite with dietary sodium intake, for potential synergy.

RESULTS

Overall, DBP increased by 3.05 mmHg (95% CI: 0, 6.06), per tertile increase in nitrite intake and 4.41 mmHg (95% CI: 0.17, 8.64) per level increase in sodium intake, when the interaction effect between nitrite and total sodium intakes was accounted for. By considering the significant synergistic effect of the two factors, DBP finally increased by 0.94 mgHg overall and 2.24 mgHg for subjects in the third tertile compared to those in the first. Also, a rise in total sodium intake of approximately 800 mg, above 1500 mg, caused a 2.30 mgHg increase in DBP. No significant correlations were found with SBP.

CONCLUSIONS

Higher nitrite and nitrate intake from processed meats contributed to the increase of DBP, but the interaction effect with total sodium intake levels should be accounted for to properly interpret the findings.

Environmental exposure to perchlorate, nitrate, and thiocyanate in relation to chronic kidney disease in the general US population, NHANES 2005-2016

BACKGROUND

Few studies have explored the impact of perchlorate, nitrate, and thiocyanate (PNT) on kidney function. This study aimed to evaluate the association of urinary levels of PNT with renal function as well as the prevalence of chronic kidney disease (CKD) among the general population in the United States.

METHODS

This analysis included data from 13,373 adults (≥20 years) from the National Health and Nutrition Examination Survey 2005 to 2016. We used multivariable linear and logistic regression, to explore the associations of urinary PNT with kidney function. Restricted cubic splines were used to assess the potentially non-linear relationships between PNT exposure and outcomes.

RESULTS

After traditional creatinine adjustment, perchlorate (P-traditional) was positively associated with estimated glomerular filtration rate (eGFR) (adjusted β: 2.75; 95% confidence interval [CI]: 2.25 to 3.26; P < 0.001), and negatively associated with urinary albumin-to-creatinine ratio (ACR) (adjusted β: -0.05; 95% CI: -0.07 to -0.02; P = 0.001) in adjusted models. After both traditional and covariate-adjusted creatinine adjustment, urinary nitrate and thiocyanate were positively associated with eGFR (all P values <0.05), and negatively associated with ACR (all P values <0.05); higher nitrate or thiocyanate was associated with a lower risk of CKD (all P values <0.001). Moreover, there were L-shaped non-linear associations between nitrate, thiocyanate, and outcomes. In the adjusted models, for quartiles of PNT, statistically significant dose-response associations were observed in most relationships. Most results were consistent in the stratified and sensitivity analyses.

CONCLUSIONS

Exposures to PNT might be associated with kidney function, indicating a potential beneficial effect of environmental PNT exposure (especially nitrate and thiocyanate) on the human kidney.

Tracking the Biostimulatory Effect of Fractions from a Commercial Plant Protein Hydrolysate in Greenhouse-Grown Lettuce

Protein hydrolysate biostimulants are environmentally friendly options for the reduction of nitrogen input, but their plant growth-promoting mechanisms are still not completely unveiled. Here, to put the “signaling peptide theory” to the test, a greenhouse experiment was undertaken using low (1 mM) and optimal (8 mM) NO3-treated butterhead lettuce and three molecular fractions (PH1 (>10 kDa), PH2 (1−10 kDa) and PH3 (<10 kDa) fractions), in addition to the whole product Vegamin®: PH, in a randomized block design. PH1 and PH3 significantly increased fresh yield (+8%) under optimal (lighter leaves), but not under low (darker leaves) NO3 conditions. Total ascorbic acid, lutein and β-carotene increased with PH3, and disinapoylgentobiose and kaempferol-3-hydroxyferuloyl-sophorosie-7-glucoside content increased with PH (whole/fractions) treatments, particularly under low NO3 conditions. The complete hydrolysate and analyzed peptide fractions have differential biostimulatory effects, enhancing the growth and nutritional quality of lettuce.

Association of urinary nitrate with diabetes complication and disease-specific mortality among adults with hyperglycemia

BACKGROUND

The hyperglycemia condition disrupts the 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.

METHODS

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 wasobtained 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 categized 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.

RESULTS

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(odd-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 of 41,463 person-year, 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 non-linearity > 0.05). Moreover, no association between nitrate and cancer mortality was observed(HR = 1.13, 95%CI:0.71-1.80).

CONCLUSIONS

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 indicated that inorganic nitrate supplementation can be considered as a supplementary treatment for people with hyperglycemia.

Dietary nitrate, aging and brain health: the latest evidence

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

SUMMARY

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.

Cleaning the Label of Cured Meat; Effect of the Replacement of Nitrates/Nitrites on Nutrients Bioaccessibility, Peptides Formation, and Cellular Toxicity of In Vitro Digested Salami

Curing salts composed of mixtures of nitrates and nitrites are preservatives widely used in processed meats. Despite many desirable technological effects, their use in meat products has been linked to methemoglobinemia and the formation of nitrosamines. Therefore, an increasing "anti-nitrite feeling" has grown among meat consumers, who search for clean label products. In this view, the use of natural compounds as alternatives represents a challenge for the meat industry. Processing (including formulation and fermentation) induces chemical or physical changes of food matrix that can modify the bioaccessibility of nutrients and the formation of peptides, impacting on the real nutritional value of food. In this study we investigated the effect of nitrate/nitrite replacement with a combination of polyphenols, ascorbate, and nitrate-reducing microbial starter cultures on the bioaccessibility of fatty acids, the hydrolysis of proteins and the release of bioactive peptides after in vitro digestion. Moreover, digested salami formulations were investigated for their impacts on cell proliferation and genotoxicity in the human intestinal cellular model (HT-29 cell line). The results indicated that a replacement of synthetic nitrates/nitrites with natural additives can represent a promising strategy to develop innovative "clean label" salamis without negatively affecting their nutritional value.

Risk Assessment of Nitrite and Nitrate Intake from Processed Meat Products: Results from the Hellenic National Nutrition and Health Survey (HNNHS)

Long-term exposure to a high nitrite and nitrate intake through processed meat is of concern, as it has been related to adverse health effects. Individual consumption data from 2152 participants (46.7% males) in the Hellenic National Nutrition and Health Survey (HNNHS) were linked with current Maximum Permitted Levels (MPLs) to calculate exposure to nitrite and nitrate from processed meat products (assessed as nitrite equivalent), evaluate potential risk and identify the major contributors. Processed meat intakes were determined by combining data from 24 h recalls and frequency of consumption reported in Food Propensity Questionnaires (FPQs). Median exposure was estimated to be within safe levels for all population groups. However, 6.6% (n = 143) of the consumers exceeded the Acceptable Daily Intake (ADI) of nitrite (0.07 mg/kg bw/day), of which 20.3% were children aged 0-9 years (N = 29) (15.3% of all children participants in the study, N = 190). In total, pork meat was the major contributor (41.5%), followed by turkey meat (32.7%) and sausages (23.8%), although contribution variations were found among age groups. The outcomes are of public health concern, especially exposure among children, and future research is warranted to evaluate possible associations with health effects, by using more refined occurrence data if available.