○ Evidence tier 3 — Human RCT — functional endpoint

Record verify: primary source pending

DesignRandomized, double-blind, placebo-controlled trial (functional/biomarker)
DOI10.1001/jamanetworkopen.2021.44279
Citation statusdoi verified via Crossref 2026-07-12 (JAMA Netw Open 2022;5(1):e2144279, Liu et al., 'Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults'). PMID + NCT: needs_primary_fulltext.

Five-qualifier claim

Species / populationOlder adults aged 65-90 (randomized, placebo-controlled trial).
Exposure, route, scheduleOral urolithin A (1000 mg/day) for 4 months.
Comparator / durationPlacebo-controlled, randomized, double-blind; 4-month intervention.
Endpoint / numeric resultImproved a muscle-endurance measure and some plasma mitochondrial biomarkers; several endpoints (e.g. 6-minute walk distance, muscle ATP) did NOT reach statistical significance.
What it did NOT establishMixed functional/biomarker result; no lifespan, disease-outcome, or healthy-aging-longevity claim is supported.

Primary reference

https://doi.org/10.1001/jamanetworkopen.2021.44279

Exact identifier confirmed against the primary record via Crossref/ClinicalTrials.gov where stated in the citation status; anything marked needs_primary_fulltext is not yet confirmed.