The Acute Effect of Ingesting a Quercetin-Based Supplement On Exercise-Induced Inflammation In Runners

Abstract

PURPOSE: This study tested the acute anti-inflammatory influence of a quercetin-based supplement consumed by endurance athletes 15-min prior to an intense 2-h run. Design: In this randomized, crossover study, 20 long distance runners (N=11 males, N=9 females, age 38.4±2.1 y, VO2max 52.6±2.0) completed two 2-h treadmill runs at 70% VO2max (3 weeks apart) that incorporated a closing 15-min time trial. In double-blinded fashion, subjects ingested either four Q-chews or placebo chews (PL) 15 min prior to the treadmill runs. The four Q-chews provided 1000 mg quercetin, 120 mg epigallocatechin 3-gallate (EGCG), 400 mg isoquercetin, 400 mg eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), 1000 mg vitamin C, and 40 mg niacinamide. Subjects provided blood samples 30 min before, immediately following and 1-h post-exercise, and were analyzed for plasma quercetin concentration, total blood leukocytes (WBC), and nine inflammatory cytokines (IL-6, TNFα, GM-CSF, IFNγ, IL-1B, IL-2, IL-8, IL-10, IL-12p70) using an electrochemiluminescence based solid-phase sandwich immunoassay (Meso Scale Discovery, Gaithersburg, MD, USA). RESULTS: Plasma quercetin was elevated from 80.0±26.0 μg/L (pre-exercise) to 6,337±414 (post-exercise) and 4,324±310 μg/L (1-h post-exercise) after ingestion of Q-chews compared to no change in PL (interaction effect, P<0.001). No difference was measured between Q-chew and PL conditions in the distance run during the 15-min time trial (3.08±0.11 and 3.13±0.11 km, respectively, P=0.370). Exercise caused significant increases in WBCs, GM-CSF, IL-10, IL-1B, IL-2, IL-6, IL-8, and TNFα, but no differences in the pattern of change were measured between Q-chew and PL trials. CONCLUSIONS: Acute ingestion of Q-chews 15 min before heavy exertion caused a strong increase in plasma quercetin levels but did not counter post-exercise inflammation relative to placebo. These data are in contrast to the anti-inflammatory effect measured with this same quercetin-based supplement when consumed for two weeks prior to a 3-day period of intensified exercise (Med Sci Sports Exerc. 2009;41:1467-75). Taken together, these data imply that a prolonged Q-chew supplementation period is needed before anti-inflammatory effects can be achieved.