Tier 2 — strong

Comparison of the urinary excretion of quercetin glycosides from red onion and aglycone from dietary supplements in healthy subjects: a randomized, single-blinded, cross-over study

Yuanlu Shi, Gary Williamson
Food & function 2015 6(5):1443

Bibliography

PubMed
PMID 25832541
DOI
10.1039/c5fo00155b
Funding
Funding was not specified in the indexed record or the disclosure metadata available for this entry.
Competing interests
A competing-interest declaration was not available in the indexed record or the disclosure metadata used for this entry.

Study snapshot

DesignRandomized single-blind crossover pharmacokinetic study
ModelHuman intervention research
Sample6 healthy nonsmoking men
InterventionRed-onion soup providing about 47 mg quercetin versus supplement providing about 544 mg
DurationSingle-dose periods; 24-hour urine collection
EndpointsExposure and pharmacokinetics

What the study showed, in plain terms

Published in 2015, this source examined forms, absorption and food sources. Design: Randomized single-blind crossover pharmacokinetic study. Sample/model: 6 healthy nonsmoking men. The exposure or intervention was Red-onion soup providing about 47 mg quercetin versus supplement providing about 544 mg. Follow-up or treatment period: Single-dose periods; 24-hour urine collection.

The onion meal produced similar urinary quercetin excretion despite a much smaller ingested amount.

Very small study using urinary excretion as an exposure proxy. The comparison is not a universal dose-conversion rule or an efficacy comparison.

Continue with Quercetin Data Center

For topic-level interpretation, read Foods High in Quercetin: Practical Sources and Portions. This is a related guide; the citation panel separately identifies articles that directly cite this paper.

Key findings

  • The onion meal produced similar urinary quercetin excretion despite a much smaller ingested amount.
  • The recorded outcome domains were Exposure and pharmacokinetics.
  • The result applies to the tested exposure: Red-onion soup providing about 47 mg quercetin versus supplement providing about 544 mg; Single-dose periods; 24-hour urine collection.

What this study can and cannot tell us

  • Very small study using urinary excretion as an exposure proxy. The comparison is not a universal dose-conversion rule or an efficacy comparison.
  • A change in blood exposure or a metabolic marker is not a demonstrated improvement in symptoms, disease events or lifespan. The tested formulation and co-administered medicines matter.
  • Source basis: Source check: PubMed abstract and indexed metadata; full methods were not independently confirmed for this entry. Missing method details, funding information or participant denominators are not inferred.

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Editorial review

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Dr. Khaled Mahmoud, MBBChCritical Care Medicine, Longevity Science & Editorial Direction Dr. Amr Yasser, PhDCardiometabolic, Musculoskeletal, Gut & Bioavailability Dr. Abdulla Mostafa, PhDCellular Senescence, Neurological, Mitochondrial & Brain-Ageing Biology