Medium-term effects of dietary nitrate supplementation on systolic and diastolic blood pressure in adults: a systematic review and meta-analysis

J Hypertens. 2017 Jul;35(7):1353-1359. doi: 10.1097/HJH.0000000000001305.


Objectives: Dietary nitrate supplementation has been shown to lower blood pressure (BP) particularly in short-term clinical trials. Whether these effects are sustained in the long-term remains to be established. The objective was to conduct a meta-analysis of randomized controlled trials that examined whether dietary nitrate supplementation for more than 1 week has beneficial effects on SBP and DBP.

Methods: Electronic databases were searched from inception until May 2016. Specific inclusion criteria were duration at least 1 week, report of effects on SBP or DBP or both and comparison of inorganic nitrate or beetroot juice supplementation with placebo control groups. Random-effects models were used to calculate the pooled BP effect sizes.

Results: Thirteen trials met eligibility criteria. The trials included a total of 325 participants with seven to 65 participants per study. The duration of each intervention ranged from 1 to 6 weeks. Ten trials assessed BP in resting clinic conditions, whereas 24-h ambulatory and daily home monitorings were used in six and three trials, respectively. Overall, dietary nitrate was associated with a significant decline in SBP [-4.1 mmHg (95% confidence interval: -6.1, -2.2); P < 0.001] and DBP [-2.0 mmHg (95% confidence interval: -3.0, -0.9); P < 0.001]. However, the effect was only significant when measured in resting clinical settings as no significant changes in BP were observed using 24-h ambulatory and daily home BP monitorings.

Conclusion: Positive effects of medium-term dietary nitrate supplementation on BP were only observed in clinical settings, which were not corroborated by more accurate methods such as 24-h ambulatory and daily home monitorings.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Adult
  • Antihypertensive Agents / administration & dosage*
  • Antihypertensive Agents / therapeutic use
  • Blood Pressure / drug effects*
  • Blood Pressure Monitoring, Ambulatory
  • Dietary Supplements*
  • Humans
  • Hypertension / drug therapy*
  • Nitrates / administration & dosage*
  • Nitrates / therapeutic use


  • Antihypertensive Agents
  • Nitrates