Effects of quercetin supplementation on markers of muscle damage and inflammation after eccentric exercise.
The flavonoid quercetin is purported to have potent antioxidant and anti-inflammatory properties. This study examined if quercetin supplementation attenuates indicators of exercise-induced muscle damage in a double-blind laboratory study. Thirty healthy subjects were randomized to quercetin (QU) or placebo (PL) supplementation and performed 2 separate sessions of 24 eccentric contractions of the elbow flexors. Muscle strength, soreness, resting arm angle, upper arm swelling, serum creatine kinase (CK) activity, plasma quercetin (PQ), interleukin-6 (IL-6), and C-reactive protein (CRP) were assessed before and for 5 d after exercise. Subjects then ingested nutrition bars containing 1,000 mg/d QU or PL for 7 d before and 5 d after the second exercise session, using the opposite arm. PQ reached 202 ± 52 ng/ml after 7 d of supplementation and remained elevated during the 5-d postexercise recovery period (p < .05). Subjects experienced strength loss (peak = 47%), muscle soreness (peak = 39 ± 6 mm), reduced arm angle (-7° ± 1°), CK elevations (peak = 3,307 ± 1,481 U/L), and arm swelling (peak = 11 ± 2 mm; p < .0001), indicating muscle damage and inflammation; however, differences between treatments were not detected. Eccentric exercise did not alter plasma IL-6 (peak = 1.9 pg/ml) or CRP (peak = 1.6 mg/L) relative to baseline or by treatment. QU supplementation had no effect on markers of muscle damage or inflammation after eccentric exercise of the elbow flexors.
Dept of Kinesiology, University of Massachusetts, Amherst, MA, USA.
Kevin S
KS
O'Fallon
Diksha
D
Kaushik
Bozena
B
Michniak-Kohn
C Patrick
CP
Dunne
Edward J
EJ
Zambraski
Priscilla M
PM
Clarkson
D000293:Adolescent; D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D000975:Antioxidants / Q000009:adverse effects / Q000032:analysis / Q000627:therapeutic use*; D001132:Arm; D015415:Biomarkers / Q000097:blood; D004311:Double-Blind Method; D004487:Edema / Q000209:etiology / Q000517:prevention & control; D005260:Female; D019648:Foods, Specialized / Q000009:adverse effects; D006801:Humans; D008297:Male; D053580:Muscle Strength; D063806:Myalgia / Q000209:etiology / Q000517:prevention & control; D009220:Myositis / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D011794:Quercetin / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D055070:Resistance Training / Q000009:adverse effects*; D062410:Snacks; D064133:Sports Nutritional Physiological Phenomena; D055815:Young Adult
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000975:Antioxidants; D015415:Biomarkers; D011794:Quercetin