The role of inorganic nitrate and nitrite in cardiovascular disease risk factors: a systematic review and meta-analysis of human evidence.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of human experimental trials
PubMed 29506204 · doi:10.1093/nutrit/nuy005
What was done
A systematic review and meta-analysis of human experimental trials identified through Medline, Embase, CINAHL, Cochrane, and Scopus. The authors evaluated the effects of oral inorganic nitrate or nitrite intake on cardiovascular disease risk factors. Thirty-four studies were included in the qualitative synthesis, with 23 eligible for quantitative meta-analysis of blood pressure, endothelial function, arterial stiffness, platelet aggregation, and blood lipids.
What was found
Inorganic nitrate significantly reduced systolic blood pressure (-4.80 mmHg, P < 0.0001) and diastolic blood pressure (-1.74 mmHg, P = 0.001). It also improved endothelial function (flow-mediated dilatation: +0.59%, P < 0.0001), reduced arterial stiffness (pulse wave velocity: -0.23 m/s, P < 0.0001; augmentation index: -2.1%, P = 0.05), and reduced platelet aggregation by 18.9% (P < 0.0001). Numerical outcomes for blood lipids were not reported in the abstract.
Why it matters
Inorganic nitrate from dietary sources like beetroot and spinach acts as a nitric oxide donor and produces clear short-term improvements across multiple physiological markers of vascular health.
Limits
The review evaluated intermediate surrogate markers rather than hard clinical cardiovascular events or mortality. Total participant count, intervention duration, dosages, and heterogeneity across studies are not reported in the abstract.
Cited by
- supports Beetroot increases nitric oxide, acting as a vasodilator and lowering blood pressure.