If older adults with a specific type of heart condition drink beetroot juice every day for a week, their resting blood pressure may drop by about 14 points — which could be a meaningful improvement for their health.

A double-blind, placebo-controlled, crossover RCT in older adults diagnosed with HFpEF, where participants consume either beetroot juice containing 6.1 mmol inorganic nitrate or a nitrate-depleted placebo juice daily for one week, with resting systolic blood pressure measured at baseline and after intervention using standardized protocols; primary outcome is mean change in systolic BP between conditions.

A prospective cohort study tracking older adults with HFpEF who voluntarily consume beetroot juice with 6.1 mmol nitrate daily for one week, compared to a matched group who do not, measuring changes in resting systolic BP using standardized methods; controlling for confounders like medication use and dietary sodium.

A case-control study comparing older HFpEF patients who experienced a ≥14 mmHg drop in resting systolic BP after one week of beetroot juice consumption (cases) to those who did not (controls), retrospectively assessing nitrate intake and adherence.

A single-arm study measuring resting systolic BP in older HFpEF patients before and after one week of daily beetroot juice consumption with 6.1 mmol nitrate, without a control group.

A small pilot study measuring plasma nitrate/nitrite levels and systolic BP in HFpEF patients before and after beetroot juice intake to explore biological plausibility, without statistical power for clinical effect.