Tier 2 — strong

Absorption and antioxidant effects of quercetin from onions, in man

G T McAnlis, J McEneny, J Pearce, I S Young
European journal of clinical nutrition 1999 53(2):92-6

Bibliography

PubMed
PMID 10099940
DOI
10.1038/sj.ejcn.1600682
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

DesignAcute dietary absorption and antioxidant pilot
ModelHuman intervention research
Sample5 healthy volunteers
InterventionFried onions 225 g
DurationBlood sampling through 48 hours
EndpointsLipid measurements; Oxidative-stress measures; Exposure and pharmacokinetics

What the study showed, in plain terms

Published in 1999, this source examined forms, absorption and food sources. Design: Acute dietary absorption and antioxidant pilot. Sample/model: 5 healthy volunteers. The exposure or intervention was Fried onions 225 g. Follow-up or treatment period: Blood sampling through 48 hours.

Plasma quercetin and one antioxidant-capacity measure increased, but LDL oxidation susceptibility did not improve.

Uncontrolled whole-food experiment with five participants. Increased plasma antioxidant capacity is not proof of cardiovascular protection.

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

  • Plasma quercetin and one antioxidant-capacity measure increased, but LDL oxidation susceptibility did not improve.
  • The recorded outcome domains were Lipid measurements; Oxidative-stress measures; Exposure and pharmacokinetics.
  • The result applies to the tested exposure: Fried onions 225 g; Blood sampling through 48 hours.

What this study can and cannot tell us

  • Uncontrolled whole-food experiment with five participants. Increased plasma antioxidant capacity is not proof of cardiovascular protection.
  • 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