Diets
dietary nitrate improves vascular function
In plain terms: Do nitrate-rich greens/beets improve blood-vessel function and lower blood pressure?
Yes for short-term BP and endothelial function; the effect is real but modest and its durability over months is less certain.
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)
How the studies fall
The evidence (12)
| 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. |
| 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. |
| 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. |
| 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. |
| 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. |
| 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). |
| 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. |
Disagree, or know a study we missed?
We grade by evidence, not opinions. The way to weigh in is to point us to a study we haven't cited (check the evidence table above first), or to flag a problem with one we have. Every submission is reviewed; if it holds up, the grade updates and shows in Science Changes Its Mind.
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.