Answer

Are biological age tests accurate?

Biological Age Testing biological-age epigenetic-clock testing longevity

By Arun AgrahriLast reviewed 3 timecoded sources

Short answer

The sources split. Two studies Precis read in full link an older biological age to higher death risk in groups. In one, which followed people for a median of over 15 years, death risk rose 39% per standard step up in GrimAge. A counted source on tape says one result does not tell you your years left.

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Based on what researchers say in public interviews on YouTube. Educational only, not medical advice. Ask a qualified clinician before changing a supplement, medication, treatment, or testing plan.

What the evidence says

positive partly neutral negative Each researcher and each study counts once per claim, however often they come up.

  1. Conflicting

    Biological age tests do not predict how long a person will live.

    3 sources: 1 positive, 2 negative.

    Researchers say

    1 positive

    Studies show

    2 negative

    2 papers we read

    27 more not counted · see why
    The study is not yet read in full. 11
    We could not tell what position it takes on this claim. 8
    We could not confirm who is speaking. 4
    The study cited could not be identified. 2
    We could not tell where the evidence comes from. 1
    A host's remark inside an interview. 1
    Show the receipts from 3 sources

    1. Peter Attia, on The Drive, at 02:58 Video · positive · Opinion

      “if you get a biological test at the age of 50 that says you are 25 before you give yourself high fives ask yourself the following question does that really mean that you're going to live another 55 years”

    2. Pooled analysis, Clin Epigenetics, 2019, PMID 30975202 Study · negative

      Both reported a significant association between increased DNAmAge and mortality risk.

    3. Other primary study, Elife, 2020, PMID 32041686 Study · negative

      During a median follow-up time of more than 15 years, we observed statistically significant BA-mortality associations for DNAmAges (GrimAge, PhenoAge, and Horvath) and functional BAs (FI, FAI, and cognitive function), where a one-SD increase of BAcorresponded to a change in mortality risk by 39, 26, 17, 32, 27, and 15%, respectively.

Where the sources disagree

Conflicting

Biological age tests do not predict how long a person will live.

Supports it 1 source
Against it 2 sources

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Detailed Answer

Three sources count, and they split. One is on tape and says a test result does not forecast one person's years left. Two are studies Precis has read in full, and both link an older biological age to a higher risk of death. The studies measure groups, while the tape talks about one person.

What the counted source on tape says

Peter Attia, on his own show, says he doesn't believe any single blood-based biomarker can predict future years of life very well. A test that tells a 50-year-old they are 25 doesn't mean another 55 years. He points people to physical performance instead: VO2 max, strength and balance, where people of the same age differ enormously.

What the counted studies found

A 2019 review pooled the research on epigenetic clocks, which read age from chemical tags on DNA. Both earlier pooled analyses it covered linked an older clock age to a higher risk of death. Its authors warn of publication bias: studies that find a link get printed more often.

A 2020 study followed people for a median of more than 15 years and tested nine measures of biological age. Every one but telomere length tracked death beyond calendar age. For each standard step up (one standard deviation, the usual spread between people), the risk of death rose 39% for GrimAge, 26% for PhenoAge and 17% for the original Horvath clock.

Studies not counted yet

Eleven more studies do not count yet. The nine Precis has read past the abstract all link an older biological age to earlier death in groups. One checked how well a blood-chemistry age picks out who will die. It was barely better than calendar age alone.

What tape outside the count adds

Steve Horvath, who developed the epigenetic clocks, was a guest on Rhonda Patrick's show (50:34). He said: "please do not translate that age estimate in your mind into an estimate when you will die… if your grim age is 10 years younger than your calendar age, it does not mean you will now live 10 years longer than the average person". Derya Unutmaz, an immunologist and guest on Patrick's show, says a blood clock reflects only the cells in your blood sample.

Mark Hyman, hosting an interview, said his own methylation age went from 43 at 62 to 39 at 64, then asked whether the clocks are reliable enough to trust that. None of these counts.

What no study here has tested

No study Precis has read tests the point made on tape: whether one person's result tells that person how many years are left. Whether you can trust your own trend across repeat tests is untested here too.

Related Questions

Can a biological age test tell you how long you will live?
Not for one person, says the counted source on tape. The two counted studies find that groups with an older biological age have a higher risk of death, but neither tests a forecast for one person. Steve Horvath, who developed the GrimAge clock, asks people not to read a result that way, in an interview that is not counted. He describes GrimAge as your risk of dying in the next year compared with people of the same age and sex.
Why might a blood-based clock mislead you?
Derya Unutmaz, in an uncounted interview, says the result reflects the mix of older and naive T cells in your blood sample. It says nothing about your skin, liver or brain.
What can you measure instead?
Physical performance. Attia points to VO2 max, strength and balance because they separate people of the same age enormously. Unutmaz, uncounted, also names physical tests, down to whether an older person can walk 100 meters better than before.
Is there any use for an epigenetic age test?
Some people use it as a trend line on themselves. Hyman, in an uncounted host remark, reported his methylation age moving from 43 to 39 while he aged two years, then asked whether the clocks are reliable enough to trust it. No study Precis has read tests that use.

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