Evidence map›Paper›PMID 20478383›Full record

Trial reportPharmacological research2010

Quercetin supplementation and upper respiratory tract infection: A randomized community clinical trial.

Serena A Heinz, Dru A Henson, Melanie D Austin, Fuxia Jin, David C Nieman

Abstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Pharmacological research, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 59 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
59citing papers in PubMed, 2 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

59 citing papers in PubMed, 2 syntheses or guidelines pooled it.

  1. Pooled it
  2. Immunostimulants for preventing respiratory tract infection in children.The Cochrane database of systematic reviews · 2006
    Pooled it
  3. Trial
  4. Trial
  5. Trial
  6. Trial
  7. Review
  8. Quercetin Hybrids and their Biological Potential.Mini reviews in medicinal chemistry · 2026
    Review
  9. Article
  10. Article
  11. Review
  12. Review
  13. Potential Use of Selected Natural Compounds with Anti-Biofilm Activity.International journal of molecular sciences · 2025
    Review
  14. Review
  15. Article
  16. Article
  17. Review
  18. Review
  19. Review
  20. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Serena A HeinzDepartment of Biology, Appalachian State University, Boone, NC 28608, USA.
Dru A Henson
Melanie D Austin
Fuxia Jin
David C Nieman

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Quercetin in culture with target cells and pathogens exerts anti-pathogenic activities against a wide variety of viruses and bacteria. A few small-scale human quercetin supplementation studies have produced conflicting results regarding quercetin's effects on upper respiratory tract infection rates, and little is known regarding the appropriate human dose. The purpose of this randomized, double-blinded, placebo-controlled trial was to measure the influence of two quercetin doses (500 and 1000 mg/day) compared to placebo on upper respiratory tract infection (URTI) rates in a large community group (N=1002) of subjects varying widely in age (18-85 years). Subjects ingested supplements for 12 weeks and logged URTI symptoms on a daily basis using the Wisconsin Upper Respiratory Symptom Survey (WURSS). No significant group differences were measured for URTI outcomes for all subjects combined, or when analyzing separately by gender, body mass index, and age categories. Regression analysis revealed that the strongest interaction effect with group status was self-reported fitness level. A separate analysis of subjects 40 years of age and older rating themselves in the top half of the entire group for fitness level (N=325) showed lower URTI severity (36% reduction, P=0.020) and URTI total sick days (31% reduction, P=0.048) for the Q-1000 group compared to placebo. In summary, for all subjects combined, quercetin supplementation over 12 weeks had no significant influence on URTI rates or symptomatology compared to placebo. A reduction in URTI total sick days and severity was noted in middle aged and older subjects ingesting 1000 mg quercetin/day for 12 weeks who rated themselves as physically fit.

Indexed as

AdolescentAdultAgedAged, 80 and overAnti-Bacterial AgentsFemaleHumansMaleMiddle AgedPlacebosQuercetinRespiratory Tract InfectionsYoung AdultAnti-Bacterial AgentsPlacebosQuercetin

Identifiers

PMID20478383
PMCPMC7128946

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.