TABLE 2.
Study characteristics and results of meta-analyses on the effect of nitrate supplementation on outcomes related to cardiovascular disease risk factors
| First author | Year | Number of studies (total number of participants) | Study population | Duration range | Nitrate source | Dose range (mg per dose) | Main outcomes | Results |
|---|---|---|---|---|---|---|---|---|
| M. Siervo [99] | 2013 | 16 (254) | Adults | 2 h to 15 d | Nitrate salt or beetroot juice | 157–1488 | Blood pressure | SBP: −4.4 mmHg (P < 0.001); DBP: −1.1 mmHg (P = 0.06) |
| J. Lara [100] | 2016 | 12 (246) | Adults | 90 min to 28 d | Nitrate salt or beetroot supplementation | 68–1488 | Vascular function parameters | Endothelial function: 0.4 (P < 0.001) |
| A. W. Ashor [101] | 2017 | 13 (325) | Adults | 1 to 6 wk | Nitrate salt or beetroot juice | 322–620 | Blood pressure | SBP: −4.1 mmHg (P < 0.001); DBP: −2.0 mmHg (P < 0.001) |
| J. K. Jackson [106] | 2018 | 34 (813) | Adults | 2 h to 70 d | Nitrate salt or dietary sources | 55–1490 | Blood pressure | SBP: −4.8 mmHg (P < 0.0001); DBP: −1.7 mmHg (P = 0.001) |
| D. Li [107] | 2020 | 47 (1101) | Adults | 3 to 168 d | Nitrate salt or dietary sources | 150–1000 | Blood pressure | SBP: −2.9 mmHg (P < 0.001); DBP: −1.5 mmHg (P < 0.001) |
| L. S. Bahrami [108] | 2021 | 27 (765) | Adults | 1 h to 6 wk | Beetroot supplementation | 70–1500 | Cardiovascular disease risk factors | SBP: −0.7 mmHg (P = 0.3); DBP: −1.3 (P = 0.06); HR: 8.6 bpm (P = 0.08); AIX: −3.3% (P = 0.1); FMD: 0.6% (P = 0.002) |
| Y. He [102] | 2021 | 22 (372) | Older adults (>60 y old) | 45 min to 4 wk | Nitrate salt or beetroot juice | 25–840 | Blood pressure | SBP: −3.9 mmHg (P < 0.001); DBP: −2.6 mmHg (P < 0.005) |
| Y. Zhang [103] | 2023 | 19 (1069) | Adults | 1 d to 4 wk | Nitrate salt or dietary sources | 248–1165 | Blood pressure | Healthy individuals: SBP: −2.42 mmHg (P = 0.01); DBP: −0.58 mmHg (P = 0.36) Hypertensive individuals: SBP: −0.82 mmHg (P = 0.35); DBP: −0.03 mmHg (P = 0.97) |
Results are expressed as mean/standardized mean differences. All meta-analyses included in this table utilized randomized controlled trials and/or placebo-controlled trials and a significance level of 5%.
Abbreviations: AIX, augmentation index; AOS, arterial oxygen saturation; DBP, diastolic blood pressure HR, heart rate; SBP, systolic blood pressure.