Tier 2 — strong

Post-160-km race illness rates and decreases in granulocyte respiratory burst and salivary IgA output are not countered by quercetin ingestion

D Henson, D Nieman, J M Davis, C Dumke, S Gross, A Murphy, M Carmichael, D P Jenkins, J Quindry, S McAnulty, L McAnulty, A Utter, E Mayer
International journal of sports medicine 2008 29(10):856

Bibliography

PubMed
PMID 18213545
DOI
10.1055/s-2007-989424
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 double-blind placebo-controlled ultramarathon trial
ModelHuman intervention research
Sample63 randomized runners; 39 finishers provided postrace samples
InterventionQuercetin 1,000 mg/day or placebo
Duration3 weeks before and 2 weeks after a 160-km race
EndpointsSource-specific outcomes described in the key findings

What the study showed, in plain terms

Published in 2008, this source examined immunity and respiratory health. Design: Randomized double-blind placebo-controlled ultramarathon trial. Sample/model: 63 randomized runners; 39 finishers provided postrace samples. The exposure or intervention was Quercetin 1,000 mg/day or placebo. Follow-up or treatment period: 3 weeks before and 2 weeks after a 160-km race.

Illness rates and exercise-related immune changes did not improve.

Same Western States cohort as related cytokine, oxidative-stress, and perceived-exertion papers. Finisher sampling and small event counts limit inference.

Continue with Quercetin Data Center

For topic-level interpretation, read Quercetin for Immune Health, Colds and COVID-19. This is a related guide; the citation panel separately identifies articles that directly cite this paper.

Key findings

  • Illness rates and exercise-related immune changes did not improve.
  • The recorded outcome domains were Source-specific outcomes described in the key findings.
  • The result applies to the tested exposure: Quercetin 1,000 mg/day or placebo; 3 weeks before and 2 weeks after a 160-km race.

What this study can and cannot tell us

  • Same Western States cohort as related cytokine, oxidative-stress, and perceived-exertion papers. Finisher sampling and small event counts limit inference.
  • An individual controlled trial must be interpreted alongside its comparator, sample size, endpoint selection and independent replication. It does not validate a different commercial formulation or a general longevity claim.
  • Companion or correction records are linked below. They should not be counted automatically as independent replications; see the individual source notes for the relationship.
  • 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.

Related papers in the corpus

Tier 2
Oral quercetin supplementation and blood oxidative capacity in response to ultramarathon competition
John C Quindry et al. · International journal of sport nutrition and exercise metabolism · 2008
Tier 2
Quercetin ingestion does not alter cytokine changes in athletes competing in the Western States Endurance Run
David C Nieman et al. · Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research · 2007
Tier 2
Quercetin does not affect rating of perceived exertion in athletes during the Western States endurance run
Alan C Utter et al. · Research in sports medicine (Print) · 2009
Tier 1
Quercetin for the treatment of COVID-19 patients: A systematic review and meta-analysis
Huzaifa Ahmad Cheema et al. · Reviews in medical virology · 2023
Tier 1
The effect of quercetin supplementation on clinical outcomes in COVID-19 patients: A systematic review and meta-analysis
Somayeh Ziaei et al. · Food science & nutrition · 2023

Editorial review

Reviewed by the Biohack Blueprint research team

Last verified

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