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
What the evidence shows
Dietary nitrate improves blood pressure and endothelial function in the short term, with randomised trials showing better flow-mediated dilation acutely and over twelve weeks in postmenopausal women. Durability is the weak point: beyond a week the blood-pressure effect attenuates, and part of beetroot juice's benefit appears to be nitrate-independent.
The evidence (21)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Walker MA, Bailey TG, McIlvenna L, Allen JD, Green DJ, Askew CD 2019 · Nutrients | RCT | supports | moderate | Acute dietary nitrate improved flow-mediated dilation of the superficial femoral artery in healthy older males. |
| Alvares TS, Pinheiro V, Proctor DN, Conte Junior CA, Nogueira Soares R 2025 · American journal of physiology. Heart and circulatory physiology | 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 Z, Mirmiran P, Kabir A, Azizi F, Ghasemi A 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 AW, Lara J, Siervo M 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, Gonçalves LDS, Junior MFT, Sousa YBA, Rebelo MA, Guimaraes CS, Tanus-Santos JE, Bueno Junior CR, Benjamim J 2026 · Antioxidants (Basel, Switzerland) | 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, Muriuki E, Kuhnle GGC, Spencer JPE, Mills CE 2026 · Nutrition reviews | 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, Perera S, Shiva S, Glynn NW, Stakich TS, Ramos SV, Distefano G, Wolf C, Kendi A, Sterczala AJ, Sipula IJ, Bello FM, Jurczak MJ, Sciurba FC, Gladwin MT, Newman AB, Coen PM 2026 · The journals of gerontology. Series A, Biological sciences and medical sciences | 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 M, Kapil V, Pearl V, Ghosh S, Ahluwalia A 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, Akasaki Y, Shibata K, Sakoda T, Tajima A, Kajiya T, Shirasawa N, Hamada N, Yoshikawa A, Kubota K, Yamashita T, Higo K, Kubozono T, Funakoshi K, Kawai R, Yoshida H, Shintani A, Kajiya K, Ohishi M 2026 · Nutrients | 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, Acton JP, O'Donnell E, Rowland SN, Shepherd AI, Perissiou M, James LJ, Clifford T, Bailey SJ 2026 · Food & function | 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 Y, Liu J, Cai H, Zhang J, Yi J, Niu Y, Xi H, Peng X, Guo L 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, Laurindo LF, Gimenez FVM, Benjamim J, Gonzaga LA, Barbosa MPCR, Martins MM, Ito EH, Barroca AL, Brito GJ, Folegatti DRMA, Porto AA, Garner DM, Barbalho SM, Valenti VE 2025 · Healthcare (Basel, Switzerland) | 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 D, Waclawovsky G, Stefani GP 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 M, Lara J, Ogbonmwan I, Mathers JC 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 JM, Gosalia J, Zhong L, Bondonno C, Petersen KS, De Souza MJ, Alipour E, Kim-Shapiro DB, Somani YB, Proctor DN 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 LS, Arabi SM, Feizy Z, Rezvani R 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, Matos-Duarte M, Ortiz S, Ramasco D, Muñoz A, Aguilar-Navarro M, López-Moreno M, Martín-López J, González-Ramos M, Berlanga L, Aagaard P, López Samanes Á 2026 · European journal of translational myology | 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 JK, Patterson AJ, MacDonald-Wicks LK, Oldmeadow C, McEvoy MA 2018 · Nutr Rev | meta-analysis | supports | moderate | Systematic review found inorganic nitrate/nitrite improved several cardiovascular risk factors including blood pressure in humans. |
| Lara J, Ashor AW, Oggioni C, Ahluwalia A, Mathers JC, Siervo M 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, Alzahrani AA, George PM, Perkins A, Philip KEJ, Alshehri MS, Fenwick PS, Alsulayyim AS, Price LC, Polkey MI, Hopkinson NS 2026 · Thorax | 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 R, Eggertsen R, Bernhardsson S, Praetorius Björk M 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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