Quercetin Ingestion Does Not Alter Cytokine Changes in Athletes Competing in the Western States Endurance Run

J Interferon Cytokine Res. 2007 Dec;27(12):1003-11. doi: 10.1089/jir.2007.0050.

Abstract

The purpose of this study was to measure the influence of quercetin on plasma cytokines, leukocyte cytokine mRNA, and related variables in ultramarathoners competing in the 160-km Western States Endurance Run (WSER). Sixty-three runners were randomized to quercetin and placebo groups and under double-blinded methods ingested 1000 mg/day quercetin for 3 weeks before the WSER. Thirty-nine of the 63 subjects (n = 18 for quercetin, n = 21 for placebo) finished the race and provided blood samples the morning before the race and 15-30 min postrace. Significant prerace to postrace WSER increases were measured for nine proinflammatory and anti-inflammatory plasma cytokines, cortisol (quercetin = 94%, placebo = 96%), serum C-reactive protein (CRP) (mean +/- SE absolute increase, quercetin = 31.8 +/- 4.2, placebo = 38.2 +/- 5.0 mg/L), and creatine kinase (CK) (quercetin = 21,575 +/- 3,977, placebo = 19,455 +/- 3,969 U/L), with no significant group differences. Interleukin-6 (IL-6) mRNA did not change post-WSER, with a significant decrease measured for leukocyte IL-8 mRNA (0.21 +/- 0.03-fold and 0.25 +/- 0.04-fold change from rest, quercetin and placebo, respectively) and significant increases for IL-1Ra mRNA (1.43 +/- 0.18-fold and 1.40 +/- 0.16-fold change, quercetin and placebo, respectively) and IL-10 mRNA (12.9 +/- 3.9-fold and 17.2 +/- 6.1-fold change, quercetin and placebo, respectively), with no significant differences between groups. In conclusion, quercetin ingestion (1 g/day) by ultramarathon athletes for 3 weeks before a competitive 160-km race significantly increased plasma quercetin levels but failed to attenuate muscle damage, inflammation, increases in plasma cytokine and hormone levels, and alterations in leukocyte cytokine mRNA expression.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Cytokines / blood*
  • Cytokines / genetics
  • Double-Blind Method
  • Female
  • Humans
  • Leukocytes / metabolism*
  • Male
  • Middle Aged
  • Physical Endurance*
  • Quercetin / administration & dosage*
  • Quercetin / analysis
  • Quercetin / blood
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Running*

Substances

  • Cytokines
  • RNA, Messenger
  • Quercetin