Diets
dietary nitrate improves vascular function
In plain terms: Do nitrate-rich greens/beets improve blood-vessel function and lower blood pressure?
Leans support Diets 🔬 Includes disconfirming
RefutedContestedStrong support
consensus score 0.44
Yes for short-term BP and endothelial function; the effect is real but modest and its durability over months is less certain.
📅 Last reviewed: 2026-07-14 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
12 support 3 contradict 1 tested null 5 mixed · 21 sources, 15 independent groups
The evidence (21)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Walker 2019 · Nutrients | RCT | supports | moderate | Acute dietary nitrate improved flow-mediated dilation of the superficial femoral artery in healthy older males. |
| Alvares TS et al 2025 · study_type: RCT | RCT | supports | moderate | 12-week nitrate-rich beetroot extract in postmenopausal women significantly improved femoral artery FMD (P<0.05) and tibialis anterior microvascular reactivity (8 & 12wk, P<0.05) vs nitrate-depleted control. Chronic (12-week) supplementatio |
| Bahadoran 2017 · Advances in Nutrition | meta-analysis | mixed | moderate | Part of beetroot juice's BP-lowering effect appears nitrate-independent, indicating the nitrate-nitric-oxide pathway does not fully account for the benefit. |
| Ashor 2017 · J Hypertension | meta-analysis | mixed | moderate | In trials of over 1 week, dietary nitrate's medium-term BP-lowering effect was attenuated and less consistent than short-term studies suggested, raising durability questions. |
| da Silva LSL et al 2026 · study_type: RCT | RCT | supports | moderate | Acute 800mg nitrate beetroot juice crossover trial in AAS-using bodybuilders: FMD greater with nitrate both pre-exercise (+2.37%, p=0.02) and post-exercise (+2.57%, p=0.01) vs placebo; no BP or strength differences. |
| Celik B et al 2026 · study_type: meta-analysis | meta-analysis | supports | moderate | Meta-analysis of 13 RCTs: inorganic nitrate improved FMD by SMD 1.48% (95% CI 0.70-2.27%, p<0.01) vs control, effect present regardless of dose/duration; acute studies showed greater FMD response (1.93%) than chronic (0.90%). |
| Forman DE et al 2026 · study_type: RCT | RCT | contradicts | moderate | 12-week oral nitrite in older adults (>=70y) showed no improvement in skeletal muscle mitochondrial respiration, exercise capacity, or physical function vs placebo; only platelet mitochondrial respiration changed acutely. Not a direct FMD/B |
| Bahra 2012 · Nitric Oxide | RCT | mixed | moderate | Inorganic nitrate ingestion lowered blood pressure and improved vascular compliance but did not change flow-mediated dilation in healthy volunteers. |
| Tokushige A et al 2026 · study_type: RCT | RCT | tested-null | low | 14-day nitrate-boosting Sakurajima radish did not improve FMD vs usual diet (p=0.58) or comparator in metabolic syndrome patients; despite raising urinary NOx, it paradoxically increased oxidative stress and raised systolic BP (+9.67 mmHg, |
| McLellan AG et al 2026 · study_type: RCT | RCT | supports | moderate | Acute dose-response RCT: 400mg nitrate improved macrovascular endothelial function (+3.07% vs control) and 800mg improved aortic systolic BP (-4 mmHg); no effect on brachial BP or cGMP. Acute (2.5h post-ingestion) effects only. |
| He 2021 · Nitric Oxide | meta-analysis | mixed | moderate | In older adults specifically, inorganic nitrate supplementation showed inconsistent and non-robust effects on blood pressure across trials. |
| Raimundo RD et al 2025 · study_type: meta-analysis | meta-analysis | mixed | moderate | Meta-analysis (10 trials) in postmenopausal women: beetroot supplementation improved post-exercise HRV/RMSSD (+6.68ms, p=0.02) but blood pressure and vascular function outcomes were not significantly pooled/improved; certainty rated low-mod |
| Forster 2026 · Nutr Res | meta-analysis | contradicts | moderate | Chronic sodium nitrate supplementation (excluding beetroot juice) did not significantly reduce SBP, DBP or heart rate in mostly older adults. |
| Siervo 2013 · J Nutr | meta-analysis | supports | moderate | Inorganic nitrate/beetroot supplementation reduced systolic BP by ~4.4 mm Hg with a dose-response relationship across 16 RCTs. |
| Delgado Spicuzza 2024 · Frontiers in Nutrition | RCT | supports | moderate | Seven-day dietary nitrate (beetroot juice) clinically improved basal macrovascular endothelial function in postmenopausal women in a placebo-controlled crossover trial. |
| Bahrami 2021 · Nitric Oxide | meta-analysis | supports | moderate | Meta-regression of RCTs found beetroot inorganic nitrate supplementation improved cardiovascular risk factors including blood pressure via nitrate-to-nitric-oxide conversion. |
| Gaos S et al 2026 · study_type: RCT | RCT | contradicts | moderate | Acute 70mL beetroot juice (6.4mmol nitrate) in older women (70-80y) improved handgrip strength but produced no changes in systolic/diastolic BP, heart rate, or 6-min walk cardiovascular responses vs placebo. |
| Jackson 2018 · Nutr Rev | meta-analysis | supports | moderate | Systematic review found inorganic nitrate/nitrite improved several cardiovascular risk factors including blood pressure in humans. |
| Lara 2016 · Eur J Nutr | meta-analysis | supports | moderate | Meta-analysis of RCTs found inorganic nitrate/beetroot supplementation improved endothelial function (flow-mediated dilation). |
| Majrshi MS et al 2026 · study_type: RCT | RCT | supports | moderate | Acute single-dose 140mL nitrate-rich beetroot juice in IPF patients improved brachial artery FMD by +4.25% (95% CI -0.71 to 8.45%; p=0.036) vs placebo. Acute effect only; small crossover trial (n=20) in a diseased population. |
| Grönroos 2024 · Nutr Metab Cardiovasc Dis | meta-analysis | supports | moderate | In hypertensive adults beetroot juice significantly lowered blood pressure and may serve as adjunct to drug therapy. |
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