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Open WellbeingWhat the studies actually measured

Long-term health and immunity

Zincand Age-related macular degeneration progression

Only one source here so far, and it measured lower age-related macular degeneration progression.

How sure anyone can be

Low certainty, level 2 of 4

Further research is likely to change this.

The numbers reported

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

0.70.83 odds ratio0.98

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, 2017 · 3 studies pooled · 3,790 participants

    Low certainty, level 2 of 4

    Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration.

    Cochrane Database Syst Rev. 2017;7(7):CD000254. doi:10.1002/14651858.CD000254.pub4. PMID:28756618.

    This source later carried a notice: Update in Cochrane Database Syst Rev. 2023 Sep 13;9:CD000254. doi: 10.1002/14651858.CD000254.pub5. The number below is exactly as the source gave it.

    Number reported
    0.83 odds ratio
    Which way it went
    Lower
    Likely range
    0.7 to 0.98
    Source’s own words
    odds ratio for progression to late AMD vs placebo
    Who was studied
    Older adult with AMD
    Compared with
    placebo
    Amount taken
    Not in the abstract
    For how long
    180 to 2,555 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's own appraisal reports serious study limitationsReported in the abstract
    3. Imprecision brought it down to Lowthe interval excludes no effect but spans a 15-fold range of effect size, from trivial to largeReported in the abstract
    4. Ends at Low2 steps down.
    Checked, nothing to step it down for
    indirectness
    Inconsistency
    No high disagreement reported between the 3 studies it pooled

    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

  • Amount taken — Not in the abstract.

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

Still to read for Zinc

Three of the nine things on our list for Zinc have no reading here yet:

  • Fetal heart-rate variability
  • Serum copper
  • Total testosterone

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.