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Open WellbeingWhat the studies actually measured

Heart and blood pressure

Sodiumand Systolic blood pressure

Only one source here so far, and it measured lower systolic blood pressure.

How sure anyone can be

High certainty, level 4 of 4

Further research is very unlikely to change this.

The numbers reported

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

-6.67-5.71 mmHg-4.74

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

One source, newest first

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 · 88 studies pooled · 3,998 participants

    High certainty, level 4 of 4

    Effects of low sodium diet versus high sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride.

    Cochrane Database Syst Rev. 2020;12(12):CD004022. doi:10.1002/14651858.CD004022.pub5. PMID:33314019.

    This source later carried a notice: Update of Cochrane Database Syst Rev. 2017 Apr 09;4:CD004022. doi: 10.1002/14651858.CD004022.pub4. The number below is exactly as the source gave it.

    Number reported
    -5.71 mmHg
    Which way it went
    Lower
    Likely range
    -6.67 to -4.74
    Source’s own words
    mmHg systolic BP, mean difference on a low-sodium versus high-sodium diet
    Who was studied
    Adult with hypertension
    Compared with
    high sodium diet
    Amount taken
    65 to 203 mmol/d sodium (reduced from 203 to 65 mmol/day)
    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, and nothing brought it down
    1. Starts at High
    2. Ends at HighNothing brought this one down a step.
    Checked, nothing to step it down for
    risk of bias, indirectness and imprecision
    Inconsistency
    No high disagreement reported between the 88 studies it pooled

    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

  • For how long — Not in the abstract.

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

Still to read for Sodium

Nine of the 18 things on our list for Sodium have no reading here yet:

  • All-cause mortality
  • Bone mineral density
  • Estimated GFR
  • Hydration Tracking
  • Kidney Stone Risk
  • LDL cholesterol
  • Left ventricular mass
  • Muscle soreness
  • Urinary calcium (24-hour)

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.