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Open WellbeingWhat the studies actually measured

Long-term health and immunity

Seleniumand All-cause mortality

Only one source here so far, and it found no clear difference in all-cause mortality.

How sure anyone can be

Moderate certainty, level 3 of 4

Further research may change this.

The numbers reported

No number has been put on this yet. One source recorded only which way the numbers went — for now, that is all we have here.

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 · 43 studies pooled

    Moderate certainty, level 3 of 4

    Selenium, antioxidants, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials.

    Am J Clin Nutr. 2020;112(6):1642-1652. doi:10.1093/ajcn/nqaa245. PMID:33053149.

    Number reported
    Not in the abstract
    Which way it went
    No clear difference
    Likely range
    Not in the abstract
    Source’s own words
    risk ratio for all-cause mortality vs control (no pooled estimate reported for selenium alone)
    Who was studied
    Adult
    Compared with
    control
    Amount taken
    Not in the abstract
    For how long
    168 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 abstract reports no confidence interval for the estimateNot 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 43 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

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

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

Still to read for Selenium

11 of the 20 things on our list for Selenium have no reading here yet:

  • Depression
  • Estimated VO2max
  • Free thyroxine (fT4)
  • Free triiodothyronine (fT3)
  • High-sensitivity CRP
  • HOMA-IR
  • Mood
  • Oxidative stress (F2-isoprostanes)
  • Plasma Selenium
  • Thyroglobulin Antibodies (TgAb)
  • Total sperm motility

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.