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Open WellbeingWhat the studies actually measured

Heart and blood pressure

Potassiumand Systolic blood pressure

Three sources here, and they say different things: two measured lower systolic blood pressure and one reported mixed results.

How sure anyone can be

Low certainty, level 2 of 4

Further research is likely to change this.

The most certain of the three 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.

-5.96-4.25 mmHg-2.53

This range stays on one side of the no-difference line.

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

Three 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, 2020 · 32 studies pooled

    Very low certainty, level 1 of 4

    Potassium Intake and Blood Pressure: A Dose-Response Meta-Analysis of Randomized Controlled Trials.

    J Am Heart Assoc. 2020;9(12):e015719. doi:10.1161/JAHA.119.015719. PMID:32500831.

    Number reported
    Not in the abstract
    Which way it went
    Mixed results
    Likely range
    Not in the abstract
    Source’s own words
    no pooled effect size: this is a dose-response spline model, and the abstract reports only the shape of the curve and its inflection points, not a magnitude at any dose
    Who was studied
    Adult
    Compared with
    control
    Amount taken
    30 to 140 mmol/day
    For how long
    28 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, 3 steps down: risk of bias, imprecision and inconsistency
    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 reports no confidence interval for the estimateNot in the abstract
    4. Inconsistency brought it down to Very lowpooled studies disagree on the direction of effectReported in the abstract
    5. Ends at Very low3 steps down.
    Checked, nothing to step it down for
    indirectness

    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

    Oral potassium supplementation for management of essential hypertension: A meta-analysis of randomized controlled trials.

    PLoS One. 2017;12(4):e0174967. doi:10.1371/journal.pone.0174967. PMID:28419159.

    Number reported
    -4.25 mmHg
    Which way it went
    Lower
    Likely range
    -5.96 to -2.53
    Source’s own words
    mmHg systolic blood pressure mean difference vs placebo
    Who was studied
    Adult with hypertension
    Compared with
    placebo
    Amount taken
    Not in the abstract
    For how long
    28 days (upper bound: Not in the abstract)
    Disagreement between studies
    I2 = 41%
    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-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, 2013

    Low certainty, level 2 of 4

    Effect of increased potassium intake on cardiovascular risk factors and disease: systematic review and meta-analyses.

    BMJ. 2013;346:f1378. doi:10.1136/bmj.f1378. PMID:23558164.

    Number reported
    -3.49 mmHg
    Which way it went
    Lower
    Likely range
    -5.15 to -1.82
    Source’s own words
    mmHg systolic blood pressure mean difference vs control
    Who was studied
    Adult
    Compared with
    control
    Amount taken
    Not in the abstract
    For how long
    Not in the abstract
    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-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

What is still missing from these readings

  • One give no number at all, only which way it went.
  • One gives no likely range, so how precise that number is is unknown.
  • Three do not say how many people took part.
  • Amount taken — Two of Three readings: Not in the abstract.
  • For how long — One of Three readings: Not in the abstract.

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

Still to read for Potassium

One of the seven things on our list for Potassium has no reading here yet:

  • Potassium

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.