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Reported associations between vitamin K-1 and both all-cause and cause-specific mortality are conflicting. The 56,048 participants from the Danish Diet, Cancer, and Health prospective cohort study, with a median [IQR] age of 56 [52-60] years at entry and of whom 47.6% male, were followed for 23 years, with 14,083 reported deaths. Of these, 5015 deaths were CVD-related, and 6342 deaths were cancer-related. Intake of vitamin K-1 (phylloquinone) was estimated from a food-frequency questionnaire (FFQ), and its relationship with mortality outcomes was investigated using Cox proportional hazards models. A moderate to high (87-192 mu g/d) intake of vitamin K-1 was associated with a lower risk of all-cause [HR (95%CI) for quintile 5 vs quintile 1: 0.76 (0.72, 0.79)], cardiovascular disease (CVD)-related [quintile 5 vs quintile 1: 0.72 (0.66, 0.79)], and cancer-related mortality [quintile 5 vs quintile 1: 0.80 (0.75, 0.86)], after adjusting for demographic and lifestyle confounders. The association between vitamin K-1 intake and cardiovascular disease-related mortality was present in all subpopulations (categorised according to sex, smoking status, diabetes status, and hypertension status), while the association with cancer-related mortality was only present in current/former smokers (p for interaction = 0.002). These findings suggest that promoting adequate intakes of foods rich in vitamin K-1 may help to reduce all-cause, CVD-related, and cancer-related mortality at the population level.

We have previously shown higher intake of cruciferous vegetables is inversely associated with carotid artery intima-media thickness. To further test the hypothesis that an increased consumption of cruciferous vegetables is associated with reduced indicators of structural vascular disease in other areas of the vascular tree, we aimed to investigate the cross-sectional association between cruciferous vegetable intake and extensive calcification in the abdominal aorta. Dietary intake was assessed, using a food frequency questionnaire, in 684 older women from the Calcium Intake Fracture Outcome Study. Cruciferous vegetables included cabbage, Brussels sprouts, cauliflower and broccoli. Abdominal aortic calcification (AAC) was scored using the Kauppila AAC24 scale on dual energy x-ray absorptiometry (DXA) lateral spine images, and was categorised as “not extensive” (0-5) or “extensive” (≥6). Mean age was 74.9 (SD 2.6) y, median cruciferous vegetable intake was 28.2 (IQR 15.0-44.7) g/d, and 128/684 (18.7%) women had extensive AAC scores. Those with higher intakes of cruciferous vegetables ( > 44.6 g/d) were associated with a 46% lower odds of having extensive AAC in comparison to those with lower intakes ( < 15.0 g/d) after adjustment for lifestyle, dietary and cardiovascular disease risk factors (ORQ4 vs Q1=0.54, 95%CI 0.30, 0.97, P=0.036). Total vegetable intake and each of the other vegetable types were not related to extensive AAC (P > 0.05 for all). This study strengthens the hypothesis that higher intake of cruciferous vegetables may protect against vascular calcification.

Background The role of nutrition in the primary prevention of peripheral artery disease (PAD), the third leading cause of atherosclerotic cardiovascular disease, is undetermined. Flavonoids may attenuate atherosclerosis and therefore persons who consume flavonoid-rich foods may have a lower risk of developing PAD. Objectives We aimed to examine the association between flavonoid intake and PAD hospitalizations and investigate if the association differs according to established risk factors for PAD. Methods Baseline data from 55,647 participants of the Danish Diet, Cancer, and Health Study without PAD, recruited from 1993 to 1997, were cross-linked with Danish nationwide registries. Flavonoid intake was calculated from FFQs using the Phenol-Explorer database. Associations were examined using multivariable-adjusted restricted cubic splines based on Cox proportional hazards models. Results After a median [IQR] follow-up time of 21 [20–22] y, 2131 participants had been hospitalized for any PAD. The association between total flavonoid intake and total PAD hospitalizations was nonlinear, reaching a plateau at ∼750–1000 mg/d. Compared with the median flavonoid intake in quintile 1 (174 mg/d), an intake of 1000 mg/d was associated with a 32% lower risk of any PAD hospitalization (HR: 0.68; 95% CI: 0.60, 0.77), a 26% lower risk of atherosclerosis (HR: 0.74; 95% CI: 0.62, 0.88), a 28% lower risk of an aneurysm (HR: 0.72; 95% CI: 0.59, 0.88), and a 47% lower risk of a hospitalization for other peripheral vascular disease (HR: 0.53; 95% CI: 0.42, 0.67). A higher total flavonoid intake was also significantly associated with a lower incidence of revascularization or endovascular surgery and lower extremity amputation. The association between total flavonoid intake and PAD hospitalizations differed according to baseline smoking status, alcohol intake, BMI, and diabetes status. Conclusions Ensuring the adequate consumption of flavonoid-rich foods, particularly in subpopulations pron

Background Dietary vitamin K (K-1 and K-2) may reduce atherosclerotic cardiovascular disease (ASCVD) risk via several mechanisms. However, studies linking vitamin K intake with incident ASCVD are limited. We aimed to determine the relationship between dietary vitamin K intake and ASCVD hospitalizations. Methods and Results In this prospective cohort study, participants from the Danish Diet, Cancer, and Health Study, with no prior ASCVD, completed a food-frequency questionnaire at baseline and were followed up for hospital admissions of ASCVD; ischemic heart disease, ischemic stroke, or peripheral artery disease. Intakes of vitamin K-1 and vitamin K-2 were estimated from the food-frequency questionnaire, and their relationship with ASCVD hospitalizations was determined using Cox proportional hazards models. Among 53 372 Danish citizens with a median (interquartile range) age of 56 (52-60) years, 8726 individuals were hospitalized for any ASCVD during 21 (17-22) years of follow-up. Compared with participants with the lowest vitamin K-1 intakes, participants with the highest intakes had a 21% lower risk of an ASCVD-related hospitalization (hazard ratio, 0.79; 95% CI: 0.74-0.84), after multivariable adjustments for relevant demographic covariates. Likewise for vitamin K-2, the risk of an ASCVD-related hospitalization for participants with the highest intakes was 14% lower than participants with the lowest vitamin K-2 intake (hazard ratio, 0.86; 95% CI, 0.81-0.91). Conclusions Risk of ASCVD was inversely associated with diets high in vitamin K-1 or K-2. The similar inverse associations with both vitamin K-1 and K-2, despite very different dietary sources, highlight the potential importance of vitamin K for ASCVD prevention.

Whether the vascular effects of inorganic nitrate, observed in clinical trials, translate to a reduction in cardiovascular disease (CVD) with habitual dietary nitrate intake in prospective studies warrants investigation. We aimed to determine if vegetable nitrate, the major dietary nitrate source, is associated with lower blood pressure (BP) and lower risk of incident CVD. Among 53,150 participants of the Danish Diet, Cancer, and Health Study, without CVD at baseline, vegetable nitrate intake was assessed using a comprehensive vegetable nitrate database. Hazard ratios (HRs) were calculated using restricted cubic splines based on multivariable-adjusted Cox proportional hazards models. During 23 years of follow-up, 14,088 cases of incident CVD were recorded. Participants in the highest vegetable nitrate intake quintile (median, 141 mg/day) had 2.58 mmHg lower baseline systolic BP (95%CI - 3.12, - 2.05) and 1.38 mmHg lower diastolic BP (95%CI - 1.66, - 1.10), compared with participants in the lowest quintile. Vegetable nitrate intake was inversely associated with CVD plateauing at moderate intakes (similar to 60 mg/day); this appeared to be mediated by systolic BP (21.9%). Compared to participants in the lowest intake quintile (median, 23 mg/day), a moderate vegetable nitrate intake (median, 59 mg/day) was associated with 15% lower risk of CVD [HR (95% CI) 0.85 (0.82, 0.89)]. Moderate vegetable nitrate intake was associated with 12%, 15%, 17% and 26% lower risk of ischemic heart disease, heart failure, ischemic stroke and peripheral artery disease hospitalizations respectively. Consumption of at least similar to 60 mg/day of vegetable nitrate (similar to 1 cup of green leafy vegetables) may mitigate risk of CVD.

We have previously shown higher intake of cruciferous vegetables is inversely associated with carotid artery intima-media thickness. To further test the hypothesis that an increased consumption of cruciferous vegetables is associated with reduced indicators of structural vascular disease in other areas of the vascular tree, we aimed to investigate the cross-sectional association between cruciferous vegetable intake and extensive calcification in the abdominal aorta. Dietary intake was assessed, using a food frequency questionnaire, in 684 older women from the Calcium Intake Fracture Outcome Study. Cruciferous vegetables included cabbage, Brussels sprouts, cauliflower and broccoli. Abdominal aortic calcification (AAC) was scored using the Kauppila AAC24 scale on dual energy x-ray absorptiometry (DXA) lateral spine images, and was categorised as “not extensive” (0-5) or “extensive” (≥6). Mean age was 74.9 (SD 2.6) y, median cruciferous vegetable intake was 28.2 (IQR 15.0-44.7) g/d, and 128/684 (18.7%) women had extensive AAC scores. Those with higher intakes of cruciferous vegetables ( > 44.6 g/d) were associated with a 46% lower odds of having extensive AAC in comparison to those with lower intakes ( < 15.0 g/d) after adjustment for lifestyle, dietary and cardiovascular disease risk factors (ORQ4 vs Q1=0.54, 95%CI 0.30, 0.97, P=0.036). Total vegetable intake and each of the other vegetable types were not related to extensive AAC (P > 0.05 for all). This study strengthens the hypothesis that higher intake of cruciferous vegetables may protect against vascular calcification.

Background The role of nutrition in the primary prevention of peripheral artery disease (PAD), the third leading cause of atherosclerotic cardiovascular disease, is undetermined. Flavonoids may attenuate atherosclerosis and therefore persons who consume flavonoid-rich foods may have a lower risk of developing PAD. Objectives We aimed to examine the association between flavonoid intake and PAD hospitalizations and investigate if the association differs according to established risk factors for PAD. Methods Baseline data from 55,647 participants of the Danish Diet, Cancer, and Health Study without PAD, recruited from 1993 to 1997, were cross-linked with Danish nationwide registries. Flavonoid intake was calculated from FFQs using the Phenol-Explorer database. Associations were examined using multivariable-adjusted restricted cubic splines based on Cox proportional hazards models. Results After a median [IQR] follow-up time of 21 [20–22] y, 2131 participants had been hospitalized for any PAD. The association between total flavonoid intake and total PAD hospitalizations was nonlinear, reaching a plateau at ∼750–1000 mg/d. Compared with the median flavonoid intake in quintile 1 (174 mg/d), an intake of 1000 mg/d was associated with a 32% lower risk of any PAD hospitalization (HR: 0.68; 95% CI: 0.60, 0.77), a 26% lower risk of atherosclerosis (HR: 0.74; 95% CI: 0.62, 0.88), a 28% lower risk of an aneurysm (HR: 0.72; 95% CI: 0.59, 0.88), and a 47% lower risk of a hospitalization for other peripheral vascular disease (HR: 0.53; 95% CI: 0.42, 0.67). A higher total flavonoid intake was also significantly associated with a lower incidence of revascularization or endovascular surgery and lower extremity amputation. The association between total flavonoid intake and PAD hospitalizations differed according to baseline smoking status, alcohol intake, BMI, and diabetes status. Conclusions Ensuring the adequate consumption of flavonoid-rich foods, particularly in subpopulations pron

Introduction Most cardiovascular disease (CVD)-related events could be prevented or substantially delayed with improved diet and lifestyle. Providing information on structural vascular disease may improve CVD risk factor management, but its impact on lifestyle change remains unclear. This study aims to determine whether providing visualisation and pictorial representation of structural vascular disease (abdominal aortic calcification (AAC)) can result in healthful diet and lifestyle change. Methods and analysis This study, including men and women aged 60–80 years, is a 12-week, two-arm, multisite randomised controlled trial. At baseline, all participants will have AAC assessed from a lateral spine image captured using a bone densitometer. Participants will then be randomised to receive their AAC results at baseline (intervention group) or a usual care control group that will receive their results at 12 weeks. All participants will receive information about routinely assessed CVD risk factors and standardised (video) diet and lifestyle advice with three simple goals: (1) increase fruit and vegetable (FV) intake by at least one serve per day, (2) improve other aspects of the diet and (3) reduce sitting time and increase physical activity. Clinical assessments will be performed at baseline and 12 weeks. Outcomes The primary outcome is a change in serum carotenoid concentrations as an objective measure of FV intake. The study design, procedures and treatment of data will adhere to Standard Protocol Items for Randomized Trials guidelines.

Introduction The Modification of Diet, Exercise and Lifestyle (MODEL) study aims to examine the impact of providing visualisation and pictorial representation of advanced structural vascular disease (abdominal aortic calcification), on ‘healthful’ improvements to diet and lifestyle. This paper reports the protocol for the process evaluation for the MODEL study. Methods and analysis The overall aim of the process evaluation is to understand the processes that took place during participation in the MODEL study trial and which elements were effective or ineffective for influencing ‘healthful’ behavioural change, and possible ways of improvement to inform wider implementation strategies. A mixed-method approach will be employed with the use of structured questionnaires and semistructured in-depth interviews. All 200 participants enrolled in the trial will undertake the quantitative component of the study and maximum variation sampling will be used to select a subsample for the qualitative component. The sample size for the qualitative component will be determined based on analytical saturation. Interviews will be digitally recorded and transcribed verbatim. Qualitative data will be analysed thematically and reported according to the Consolidated Criteria for Reporting Qualitative Research (COREQ) guidelines. Ethics and dissemination The MODEL study process evaluation has received approval from Edith Cowan University Human Research Ethics Committee (Project Number: 20513 HODGSON). Written informed consent will be obtained from all participants before they are included in the study. The study results will be shared with the individuals and institutions associated with this study as well as academic audiences through peer-reviewed publication and probable presentation at conferences.

BACKGROUND: Higher intakes of flavonoids provide health benefits, however, the importance of each flavonoid class and which population groups may receive the greatest protection from higher flavonoid intake warrants further investigation. OBJECTIVE: To explore the associations of flavonoid and flavonoid-rich wholefood intakes with all-cause mortality and the moderating effects of early mortality risk factors. DESIGN: The study included 2349 participants of The Blue Mountains Eye Study, with a mean ± SD age at baseline of 64.7 ± 9.2 years. Flavonoid intake was calculated from baseline food frequency questionnaires using US Department of Agriculture food composition databases. Associations were examined using adjusted Cox proportional hazards models. RESULTS: After 14 years of follow-up, 677 participants died. There was a flavonoid threshold effect with the greatest risk reduction seen between low and moderate intakes of total flavonoids, flavonoid classes and flavonoid-rich foods. Amongst the whole cohort, participants in the highest tertile of anthocyanidin intake had a significantly lower risk of all-cause mortality [multivariable adjusted HR (95%CI): 0.76 (0.61, 0.94)] when compared to those in the lowest tertile. Amongst participants with at least one early mortality risk factor (smoking, high alcohol consumption, no regular exercise or obesity), risk of all-cause mortality was lower in those in the highest intake tertile for total flavonoids [adjusted HR: 0.77 (0.59, 1.00)], flavan-3-ols [0.75 (0.58, 0.98)], anthocyanidins [0.70 (0.54, 0.92)], and proanthocyanidins [0.69 (0.52, 0.92)], compared to those in the lowest tertile. No similar associations were observed among those without any risk factors. Similarly, consumption of apples, tea and the individual flavonoid compounds, quercetin and epicatechin, were associated with a lower risk of all-cause mortality among participants with at least one risk factor, but not amongst other participants. CONCLUSION: Modera

Background & aims: Primary prevention of atrial fibrillation (AF) through behavioural and dietary modification is a critically important and unmet need. Flavonoids are bioactive dietary compounds with promising cardiovascular health benefits. Our aim was to investigate the association between flavonoid intake and clinically apparent AF. Methods: Baseline data from 55 613 participants of the Danish Diet, Cancer and Health Study, without AF, recruited between 1993 and 1997, were cross-linked with Danish nationwide registries. Total flavonoid and flavonoid subclass intakes were calculated from validated food frequency questionnaires using the Phenol-Explorer database. Associations between flavonoid intake and incident AF (first-time hospitalization or outpatient visit) were examined using restricted cubic splines based on Cox proportional hazards models. Results: During a median [IQR] follow-up of 21 [18–22] years, 7291 participants were diagnosed with AF. Total flavonoid intake was not statistically significantly associated with risk of incident AF in the whole cohort. However, compared to the lowest quintile, a total flavonoid intake of 1000 mg/day was associated with a lower risk of AF in smokers [0.86 (0.77, 0.96)] but not in non-smokers [0.96 (0.88, 1.06)], and a lower risk of AF in high alcohol consumers [ > 20 g/d: 0.84 (0.75, 0.95)] but not in low-to-moderate alcohol consumers [ < 20 g/d: 0.97 (0.89, 1.07)]. Conclusion: Intake of flavonoids was not significantly associated with a lower risk of incident AF. However, higher intakes of flavonoids may be beneficial for those at a higher risk of developing AF.

A higher intake of food rich in flavonoids such as quercetin can reduce the risk of CVD. Enzymatically modified isoquercitrin (EMIQ®) has a bioavailability 17-fold higher than quercetin aglycone and has shown potential CVD moderating effects in animal studies. The present study aimed to determine whether acute ingestion of EMIQ® improves endothelial function, blood pressure (BP) and cognitive function in human volunteers at risk of CVD. Twenty-five participants (twelve males and thirteen females) with at least one CVD risk factor completed this randomised, controlled, crossover study. In a random order, participants were given EMIQ® (2 mg aglycone equivalent)/kg body weight or placebo alongside a standard breakfast meal. Endothelial function, assessed by flow-mediated dilatation (FMD) of the brachial artery was measured before and 1·5 h after intervention. BP, arterial stiffness, cognitive function, BP during cognitive stress and measures of quercetin metabolites, oxidative stress and markers of nitric oxide (NO) production were assessed post-intervention. After adjustment for pre-treatment measurements and treatment order, EMIQ® treatment resulted in a significantly higher FMD response compared with the placebo (1·80 (95 % CI 0·23, 3·37) %; P = 0·025). Plasma concentrations of quercetin metabolites were significantly higher (P < 0·001) after EMIQ® treatment compared with the placebo. No changes in BP, arterial stiffness, cognitive function or biochemical parameters were observed. In this human intervention study, the acute administration of EMIQ® significantly increased circulating quercetin metabolites and improved endothelial function. Further clinical trials are required to assess whether health benefits are associated with long-term EMIQ® consumption.

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Dietary flavonoids are vasoactive phytochemicals with promising anti-inflammatory properties. We aimed to assess the associations between baseline intakes of six commonly consumed flavonoid subclasses and 10-year incidence of age-related hearing loss. At baseline, 1691 participants aged 50+ years had information on dietary intakes and hearing status. Hearing loss was defined as the pure-tone average of frequencies 0.5, 1.0, 2.0, and 4.0 kHz > 25 dB hearing level (HL). Dietary data were collected through a semi-quantitative food frequency questionnaire. The flavonoid content of foods was estimated using US databases. During the 10-year follow-up, 260 (31.6%) new cases of hearing loss (incident) were observed. After multivariable adjustment, participants in the fourth versus first quartile (reference group) of intake of dietary isoflavone had 36% lower risk of incident hearing loss after 10 years: odds ratios (OR) 0.64 (95% confidence intervals, CI, 0.42–0.99); p-value for trend = 0.03. Nonsignificant associations were observed between the other five flavonoid subclasses and 10-year incidence of hearing loss. Our findings do not support the hypothesis that the intake of dietary flavonoids protect against long-term risk of hearing loss. The association with isoflavone intake needs to be confirmed by other population-based studies.

A diet rich in fruits and vegetables is recommended for cardiovascular health. However, the majority of Australians do not consume the recommended number of vegetable servings each day. Furthermore, intakes of vegetables considered to have the greatest cardiovascular benefit are often very low. Results from prospective observational studies indicate that a higher consumption of cruciferous vegetables (e.g. broccoli, cabbage, cauliflower) is associated with lower cardiovascular disease risk. This may be due to the presence of specific nutrients and bioactive compounds found almost exclusively, or at relatively high levels, in cruciferous vegetables. Therefore, the aim of this randomised controlled crossover trial is to determine whether regular consumption of cruciferous vegetables results in short-term improvement in measures related to cardiovascular disease risk, including ambulatory blood pressure, arterial stiffness, glycaemic control, and circulating biomarkers of oxidative stress and inflammation.

Information on the composition of chlorogenic acid, caffeine and antioxidant activity of Coffea liberica is scarce, albeit the importance of this species in some parts of the world. This study assessed the composition of chlorogenic acid, total phenolic, caffeine and free radical scavenging activity in green and roasted C. liberica in comparison to C. arabica. The compositions of these compounds were also investigated in C. liberica at different roasting degree. We found a comparable amount of chlorogenic acid in green C. liberica and C. arabica. However, roasted C. arabica had a significantly higher chlorogenic acid content than roasted C. liberica (p<0.05). Chlorogenic acid content significantly reduced in C. liberica after roasting when compared to green beans (p<0.05). There was an insignificant difference of caffeine content between the green and roasted beans of both coffee varieties. Total phenolic content were of comparable value between C. liberica and C. arabica for both green and roasted beans. There was a trend for higher total phenolic content in roasted C. liberica when compared to green beans, although significant difference was observed only in medium-dark roast (p<0.05). DPPH scavenging activity was comparable between C. arabica and C. liberica for both green and roasted beans, and was significantly reduced in C. liberica after roasting (p<0.05). Both green C. arabica and C. liberica had similar DPPH scavenging activity to the standards (BHT and a-tocopherol). These data can aid in promoting the production of C. liberica alongside C. arabica that has been regarded as a premium quality coffee.

Nitric oxide (NO) facilitates anti-atherosclerotic effects. Vegetables are a major source of dietary nitrate. Experimental data indicates that dietary nitrate can significantly reduce major risk factors for atherosclerosis and subsequent cardiovascular disease (CVD), as nitrate can be metabolized to produce NO via the nitrate-nitrite-NO pathway. The purpose of this study was to prospectively investigate the association between habitual dietary nitrate intakes and the incidence of self-reported CVD-related complications within a representative sample of middle-aged Australian women (1946–1951 cohort of the Australian Longitudinal Study on Women’s Health). Women free from disease at baseline who had completed the food frequency questionnaire data were included. Generalized estimating equations were used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) across quartiles for nitrate intakes. Of the 5324 women included for analysis, there were 1951 new cases of CVD-related complications over 15-years of follow-up. Women reporting higher total dietary nitrate intakes (Q4 > 78.2 mg/day) and vegetable nitrate intakes (Q4 > 64.4 mg/day) were 25% and 27% reduced risk of developing CVD-related complications respectively, compared with women reporting low total (Q1 < 45.5 mg/day) and vegetable nitrate intakes (Q1 < 34.8 mg/day). Our findings were consistent with other observational data indicating that dietary nitrate may explain some of the cardiovascular benefits of vegetable consumption. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

Background: Flavonoids, compounds found in plant-based foods and beverages, might ameliorate vascular damage and atherosclerosis. Therefore, our aim was to assess the association between flavonoid intake and hospital admissions due to atherosclerotic cardiovascular disease. Methods: In this prospective cohort study, participants from the Danish Diet, Cancer, and Health Study were cross-linked with Danish nationwide registries. Eligible participants were aged 50–65 years, had no previous history of atherosclerotic cardiovascular disease, and had completed a food-frequency questionnaire at baseline. We examined associations between flavonoid intake (calculated from food-frequency questionnaires with use of the Phenol-Explorer database) and hospital admissions for atherosclerotic cardiovascular disease, ischaemic heart disease, ischaemic stroke, or peripheral arterial disease. We obtained hazard ratios (HRs) using restricted cubic splines based on Cox proportional hazards models. Findings: Of the participants recruited to the Danish Diet, Cancer, and Health study between 1993 and 1997, our study population was comprised of 53 552 participants, with a median follow-up of 21 years (IQR 15–22). During follow-up, 8773 participants were admitted to hospital for atherosclerotic cardiovascular disease. We observed non-linear associations between flavonoid intake and hospital admissions, plateauing at total flavonoid intakes of approximately 1000 mg per day. Compared with an intake of 175 mg per day, an intake of 1000 mg per day was associated with a 14% lower risk of atherosclerotic cardiovascular disease (HR 0·86, 95% CI 0·81–0·91). For disease subtypes, we observed a 9% lower risk of ischaemic heart disease (0·91, 0·85–0·98), a non-significant 9% lower risk of ischaemic stroke (0·91, 0·82–1·01), and a 32% lower risk of peripheral artery disease (0·68, 0·60–0·78). The overall associations were stronger in smokers than in non-smokers, as well as stronger in consumers of hi

Background Dietary nitrate is an important source of nitric oxide (NO), a molecule critical for cardiovascular health. Nitrate is sequentially reduced to NO through an enterosalivary nitrate-nitrite-NO pathway that involves the oral microbiome. This pathway is considered an important adjunct pathway to the classical l-arginine–NO synthase pathway. Objective The objective of this study was to systematically assess the evidence for dietary nitrate intake and improved cardiovascular health from both human and animal studies. Design A systematic literature search was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by using key search terms in Medline and EMBASE databases and defined inclusion and exclusion criteria. Results Thirty-seven articles on humans and 14 articles on animals were included from 12,541 screened references. Data on the effects of dietary nitrate on blood pressure, endothelial function, ischemic reperfusion injury, arterial stiffness, platelet function, and cerebral blood flow in both human and animal models were identified. Beneficial effects of nitrate on vascular health have predominantly been observed in healthy human populations, whereas effects in populations at risk of cardiovascular disease are less clear. Few studies have investigated the long-term effects of dietary nitrate on cardiovascular disease clinical endpoints. In animal studies, there is evidence that nitrate improves blood pressure and endothelial function, particularly in animal models with reduced NO bioavailability. Nitrate dose seems to be a critical factor because there is evidence of cross-talk between the 2 pathways of NO production. Conclusions Evidence for a beneficial effect in humans at risk of cardiovascular disease is limited. Furthermore, there is a need to investigate the long-term effects of dietary nitrate on cardiovascular disease clinical endpoints. Further animal studies are required to elucidate the

Background - Emerging evidence suggests that increasing intakes of nitrate-rich vegetables may be an effective approach to reduce blood pressure. Objective - Our primary aim was to determine whether daily consumption of nitrate-rich vegetables over 4 wk would result in lower blood pressure. Design - Thirty participants with prehypertension or untreated grade 1 hypertension were recruited to a randomized controlled crossover trial with 4-wk treatment periods separated by 4-wk washout periods. Participants completed 3 treatments in random order: 1) increased intake (∼200 g/d) of nitrate-rich vegetables [high-nitrate (HN); ∼150 mg nitrate/d], 2) increased intake (∼200 g/d) of nitrate-poor vegetables [low-nitrate (LN); ∼22 mg nitrate/d], and 3) no increase in vegetables (control; ∼6 mg nitrate/d). Compliance was assessed with the use of food diaries and by measuring plasma nitrate and carotenoids. Nitrate metabolism was assessed with the use of plasma, salivary, and urinary nitrate and nitrite concentrations. The primary outcome was blood pressure assessed by using 24-h ambulatory, home, and clinic measurements. Secondary outcomes included measures of arterial stiffness. Results - Plasma nitrate and nitrite concentrations increased with the HN treatment in comparison to the LN and control treatments (P < 0.001). Plasma carotenoids increased with the HN and LN treatments compared with the control (P < 0.01). HN treatment did not reduce systolic blood pressure [24-h ambulatory—HN: 127.4 ± 1.1 mm Hg; LN: 128.6 ± 1.1 mm Hg; control: 126.2 ± 1.1 mm Hg (P = 0.20); home—HN: 127.4 ± 0.7 mm Hg; LN: 128.7 ± 0.7 mm Hg; control: 128.3 ± 0.7 mm Hg (P = 0.36); clinic—HN: 128.4 ± 1.3 mm Hg; LN: 130.3 ± 1.3 mm Hg; control: 129.8 ± 1.3 mm Hg (P = 0.49)] or diastolic blood pressure compared with LN and control treatments (P > 0.05) after adjustment for pretreatment values, treatment period, and treatment order. Similarly, no differences were observed between treatments for arterial stiff