Cited by 109Nitric Oxide and Endothelin EffectsCardiovascular Health and Disease PreventionSodium Intake and Health

The DOI matches its Crossref record; 37 of the 37 references it cites were found in a registry or an index; 1 of the 32 sources its claims cite were checked for support.

High-nitrate vegetable diet increases plasma nitrate and nitrite concentrations and reduces blood pressure in healthy women

Open access

Abstract

Objective: Epidemiological studies suggest that green leafy vegetables, which are high in dietary nitrate, are protective against CVD such as stroke. High blood pressure (BP) is a major risk factor for stroke and inorganic nitrate has been shown to reduce BP. The objective of the present study was to test the hypothesis that diets containing high-nitrate (HN) vegetables would increase plasma nitrate and nitrite concentrations and reduce BP in healthy women. Design: A randomized, crossover trial, where participants received HN vegetables (HN diet) or avoided HN vegetables (Control diet) for 1 week. Before and after each intervention, resting BP and plasma nitrate and nitrite concentrations were measured. Setting: University of Exeter, UK. Subjects: Nineteen healthy women (mean age 20 (sd 2) years; mean BMI 22·5 (sd 3·8) kg/m 2). Results: The HN diet significantly increased plasma nitrate concentration (before HN diet: mean 24·4 (sd 5·6) µmol/l; after HN diet: mean 61·0 (sd 44·1) µmol/l,P<0·05) and plasma nitrite concentration (before HN diet: mean 98 (sd 91) nmol/l; after HN diet: mean 185 (sd 34) nmol/l,P<0·05). No significant change in plasma nitrate or nitrite concentration was observed after the Control diet. The HN diet significantly reduced resting systolic BP (before HN diet: mean 107 (sd 9) mmHg; after HN diet: mean 103 (sd 6) mmHg,P<0·05). No significant change in systolic BP was observed after the Control diet (before Control diet: mean 106 (sd 8) mmHg; after Control diet: mean 106 (sd 8) mmHg). Conclusions: Consumption of HN vegetables significantly increased plasma nitrate and nitrite concentrations and reduced BP in normotensive women.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

In a randomized crossover trial in 19 healthy premenopausal women, one week of high-nitrate vegetables increased plasma nitrate and nitrite and lowered systolic BP by about 4 mmHg. The control diet avoiding high-nitrate vegetables did not change these measures.

Key findings

  • The high-nitrate (HN) diet increased plasma nitrate from 24.4 (SD 5.6) to 61.0 (SD 44.1) µmol/l (P < 0.05) and plasma nitrite from 98 (SD 91) to 185 nmol/l (P < 0.05; abstract reports SD 34, results section reports SD 146); the Control diet produced no significant changes.
  • The HN diet reduced resting systolic BP from 107 (SD 9) to 103 (SD 6) mmHg (P < 0.05), while Control systolic BP was unchanged (106 (SD 8) to 106 (SD 8) mmHg). Diastolic BP and mean arterial pressure were not significantly affected.
  • Estimated nitrate intake was 339 (SD 133) mg/d on the HN diet vs 8 (SD 6) mg/d on the Control diet (P < 0.001); total polyphenols, K, Ca and Mg intakes were also significantly higher on the HN diet.
  • Baseline systolic BP correlated with the change in systolic BP after the HN diet (r = −0.74, P < 0.001); estimated nitrate intake did not correlate with systolic BP change (r = 0.002, P = 0.99).

Methods

  • Randomized crossover trial: 30 healthy, non-smoking, premenopausal women were enrolled; 10 were excluded or withdrew, and one additional participant was excluded because baseline plasma nitrite was >3 SD outside the group mean, leaving 19 analyzed (mean age 20 (SD 2) years; mean BMI 22.5 (SD 3.8) kg/m²).
  • Participants received HN vegetables or avoided HN vegetables for 1 week, with a 3-week wash-out between conditions; BP was measured with an automated sphygmomanometer, plasma nitrate and nitrite by modified chemiluminescence, and diet by 7-day food diary with nutritional analysis.
  • Paired-sample t tests, two-way repeated-measures ANOVA with least significant difference follow-up, and Pearson correlations were used; significance was accepted at P < 0.05.

Limitations

  • Stated by the authors: food diaries did not assess total macro- and micronutrient intake from all foods; nitrate intake was estimated from self-reported vegetable consumption and indirect vegetable nitrate content; the acute effect may have been measured because vegetables were eaten 2–3 h before final testing; a placebo effect was possible; menstrual-cycle variability and a fixed wash-out were concerns; one participant was excluded after being >3 SD from the mean, leaving statistical power of 64% vs the predicted 80%.
  • Evident from the text: the sample was small (n 19), the intervention was short (1 week), and participants were healthy, normotensive, young women, limiting generalizability; nitrate content of the consumed vegetables was not directly measured.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1017/s1368980015000038

Cites

37 of 37 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

30 Own method · 28 Not checked yet · 23 Own result · 14 Own interpretation · 1 Partly supported · 1 No basis given · accuracy not yet measured

Verify all 31 references — free account
  • Probably not a substantial claim. 44
  • It may state two separate claims as one. 21
  • The quote only partly states this claim. 1
54 of 54
  • The paper relies on this without support.

    There have been no published studies investigating the physiological effects of increasing dietary nitrate intake in women using fresh, green leafy vegetables readily available in the UK.

    “There have been no published studies investigating the physiological effects of increasing dietary nitrate intake in women using fresh, green leafy vegetables readily available in the UK.”
  • The paper relies on this without support.

    Specific nutrients or polyphenols in fruit and vegetables responsible for their health-promoting effects have not been identified.

    “However, specific nutrients or polyphenols in fruit and vegetables responsible for their health-promoting effects have not been identified.”
  • The paper relies on this without support.

    The 7-day food diaries accurately estimated participants' dietary intake.

    “Participants were requested to provide an estimated record of their intake during both HN and Control diets using a 7 d food diary and to describe portions as household measures.”
  • The paper relies on this without support.

    The specific constituent(s) of the DASH diet which contribute to its success are unknown.

    “The specific constituent(s) of the DASH diet which contribute to its success is/are unknown.”
4 of 4

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

2 of 2

Citations

Cites

Show all 37 references

Research works printed but not linked: 3

  1. 2010, IARC Monographs on the Evaluation of Carcinogenic Risks to Humans
  2. 2008, Opinion of the Scientific Panel on Contaminants in the Food Chain on a request from the European Commission to perform a scientific risk assessment on nitrate in vegetables, EFSA J, 689, 1
  3. 2002, McCance and Widdowson’s The Composition of Foods, Sixth Summary Edition

Cited by

Sorted by citations

See all 109

Metadata

Authors
Ashworth, A., Mitchell, K., Blackwell, J. R., Vanhatalo, A., & Jones, A. M.
Affiliations
University of Exeter (GB)
Corresponding author
Jones, Andrew M
Venue
Public Health Nutrition
Published
2015-02-16
Volume
18
Issue
14
Pages
2669-2678
ISSN
  • 1368-9800 (ISSN-L)
  • 1475-2727
OpenAlex
W2111751631
Cited by
109
References
37
Citations by year
2026: 6 · 2025: 4 · 2024: 9 · 2023: 6 · 2022: 9 · 2021: 13 · 2020: 15 · 2019: 7 · 2018: 15 · 2017: 16 · 2016: 6 · 2015: 3
FWCI
9.82
Type
journal article
Language
en
Open access
Locations
  • Public Health Nutrition (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Physiology (medical) › Nitric Oxide and Endothelin Effects
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiovascular Health and Disease Prevention
  • Health Sciences › Nursing › Nutrition and Dietetics › Sodium Intake and Health
Keywords
dietary nitrate, leafy vegetables, plasma nitrate, plasma nitrite, blood pressure, systolic blood pressure, healthy women, stroke risk, cardiovascular disease prevention
MeSH terms
Adolescent, Adult, Blood Pressure, Diet, Feeding Behavior, Female, Humans, Hypertension, Nitrates, Nitrites, Reference Values, Vegetables, Cross-Over Studies, Young Adult

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

A language model drew the claims from the paper on 2026-10-09, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).

A second model labelled each claim on 2026-10-09 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).

Cited sources are checked with a language model’s help (gpt-6-sol).

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review