Regulatory effect of dietary nitrate on blood pressure: a meta-analysis of randomized controlled trials
Meta-analysis of 19 RCTs on inorganic nitrate supplementation: in healthy adults pooled systolic BP was lower versus control (−2.42 mmHg; 95% CI −4.28 to −0.57; p=0.01) without significant diastolic change; in hypertensive adults this pooled model did not show significant systolic or diastolic reductions—contrasts with beetroot-juice–only hypertension syntheses.
Design
- Databases: PubMed, Embase, Cochrane Library through Dec 2021
- Included: RCTs of inorganic nitrate supplementation reporting office or 24 h ambulatory BP
- Corpus: 19 articles (population mix includes healthy and hypertensive labels in subgroup analyses)
Pooled results (RevMan random-effects; abstract)
- Healthy subgroup — SBP: −2.42 mmHg (95% CI −4.28 to −0.57; p = 0.01)
- Healthy subgroup — DBP / MAP: not significant in abstract summary
- Hypertensive subgroup — SBP / DBP / 24 h ABPM: no significant pooled reductions in the authors’ models
Interpretation for this wiki
Use as a counterweight / heterogeneity lesson next to Benjamim et al. 2022, which restricted to beetroot juice in hypertension and found a larger pooled systolic signal—differences likely reflect trial selection, vehicle, baseline BP, and duration, not a simple contradiction to resolve by slogan.
Evidence hygiene
Oral nitrate studies vary in background diet, antihypertensive co-medication, and placebo juice nitrate depletion—always read per-trial arms before changing prescriptions.
Outcomes
- Systolic Blood Pressure-2.42mmHg (Millimetres of Mercury)
- Hypertensive subgroup in this 19-trial pooled model: no significant SBP, DBP, or 24 h ambulatory BP reductions reported in the abstract—contrast with BRJ-only hypertension MA (PMID 35369064) on this protocol.