Eating a little more nitrate-rich food each day—like spinach or beets—might help keep your arteries more flexible as you age, making your blood flow a bit easier.

A double-blind, placebo-controlled RCT in healthy adults aged 40–70, where participants receive either 1 mmol/day of dietary nitrate (via beetroot juice or standardized supplement) or placebo for 12 weeks, with PWV measured at baseline, 6 weeks, and 12 weeks to detect a 0.07 m/s change.

A longitudinal cohort study tracking 1,000 middle-aged adults over 2 years, measuring daily dietary nitrate intake via food diaries and PWV at baseline and annually, to assess whether each 1 mmol/day increase in nitrate intake predicts a 0.07 m/s annual decline in PWV after adjusting for age, BP, and BMI.

A meta-analysis pooling individual participant data from 5–8 RCTs or cohort studies that measured both dietary nitrate intake (in mmol/day) and PWV, to estimate the linear dose-response relationship between nitrate intake and PWV change, specifically testing whether 1 mmol/day corresponds to 0.07 m/s reduction.

An ancillary study within an RCT measuring nitrate metabolites (nitrite, NOx), endothelial function (FMD), and PWV before and after 1 mmol/day nitrate intake to test whether the 0.07 m/s PWV reduction correlates with changes in NO bioavailability.

A population survey measuring self-reported nitrate-rich food intake and PWV in a single time point to see if individuals consuming ~1 mmol/day more nitrate have lower PWV, though unable to infer direction or causality.