Skip to the main content
Open WellbeingWhat the studies actually measured

Heart and blood pressure

Dietary nitrateand Diastolic blood pressure

Two sources here, and they say different things: one measured lower diastolic blood pressure and one found no clear difference.

How sure anyone can be

Moderate certainty, level 3 of 4

Further research may change this.

The most certain of the two findings here; each record carries its own.

The numbers reported

One source’s range, drawn against its own line of no difference and scaled to its own numbers.

-4.37-2 mmHg0.38

This range crosses the no-difference line, so these numbers fit a real difference and no difference at all equally well.

Bar the confidence interval — the range the true effect is likely to sit inNotch the number the source reportedLine where there would be no difference at all

Two sources, newest first

We do not pick between these or average them into one number.

What we read is the published abstract, not the full paper, so a blank below may still be printed in the paper itself. A fixed rule worked this out from the source’s own fields. Nobody checked this rating by hand.

  • Systematic review, 2026 · 6 studies pooled

    Moderate certainty, level 3 of 4

    Effects of chronic nitrate supplementation on blood pressure in adults: a systematic review and meta-analysis of randomized clinical trials.

    Nutr Res. 2026;146:111-120. doi:10.1016/j.nutres.2025.08.002. PMID:41619653.

    Number reported
    -2 mmHg
    Which way it went
    No clear difference
    Likely range
    -4.37 to 0.38
    Source’s own words
    mm Hg mean difference in diastolic blood pressure vs placebo
    Who was studied
    Older adult
    Compared with
    placebo
    Amount taken
    Recorded detail — sodium nitrate (beetroot juice trials excluded)
    For how long
    7 days (upper bound: Not in the abstract)
    Disagreement between studies
    Not in the abstract
    Kind of record
    Journal article
    How this rating was reachedstarts at High, one step down: imprecision
    1. Starts at High
    2. Imprecision brought it down to Moderatethe confidence interval includes no effectReported in the abstract
    3. Ends at ModerateOne step down.
    Checked, nothing to step it down for
    risk of bias and indirectness
    Inconsistency
    No high disagreement reported between the 6 studies it pooled

    Imprecision stops at the first check that applies; others may apply too.

    AI-reviewed & signed — an AI agent re-read this finding against the saved source and checked that the quote, the numbers, the units and the direction match it. No person read it. The owner authorised the agent to sign the batch with the owner's key, and every build rechecks that signature against these exact bytes.

    Read the abstract on PubMed

  • Systematic review, 2017

    Low certainty, level 2 of 4

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

    J Hypertens. 2017;35(7):1353-1359. doi:10.1097/HJH.0000000000001305. PMID:28319596.

    Number reported
    -2 mmHg
    Which way it went
    Lower
    Likely range
    -3 to -0.9
    Source’s own words
    mm Hg pooled change in diastolic blood pressure vs placebo control
    Who was studied
    Adult
    Compared with
    placebo control
    Amount taken
    Recorded detail — inorganic nitrate or beetroot juice
    For how long
    7 to 42 days
    Disagreement between studies
    Not in the abstract
    Kind of record
    Journal article
    How this rating was reachedstarts at High, 2 steps down: risk of bias and imprecision
    1. Starts at High
    2. Risk of bias brought it down to Moderatethe abstract reports no risk-of-bias or quality appraisal, so study limitations cannot be ruled outNot in the abstract
    3. Imprecision brought it down to Lowthe abstract does not state how many participants were pooledNot in the abstract
    4. Ends at Low2 steps down.
    Checked, nothing to step it down for
    indirectness
    Inconsistency
    No disagreement reported, and no count of studies behind it

    Imprecision stops at the first check that applies; others may apply too.

    AI review could not confirm it — an AI agent re-read this finding against the saved source and at least one check failed. The batch record names the check and quotes the sentence that caused the doubt. No person read it.

    Read the abstract on PubMed

What is still missing from these readings

  • Two do not say how many people took part.

Something nobody wrote down is never a zero and never a guess.

Still to read for Dietary nitrate

One of the five things on our list for Dietary nitrate has no reading here yet:

  • Plasma nitrate

Still to read means nobody here has got to it, not that it was tried and did nothing or that no research exists. A pairing on no list is not a gap: we never set out to read it.

Read next

This is a library, not advice. No recommendation, no dose, no diagnosis, no ranking. We never ask about your symptoms, and nothing here is tailored to you.