The Effects of Dha Supplementation on Markers of Inflammation and Muscle Damage Following an Acute Eccentric Exercise Bout

Aim: The purpose of this study was to investigate the influence of docosahexaenoic acid (DHA) on muscle damage and inflammation following an acute eccentric exercise bout. Methods: A double-blind placebo-controlled, study was performed using 41 healthy, untrained males aged 18-28 y who consumed either 2 g/d DHA or placebo (PL, corn oil) for 32 days. Supplements were consumed for 28 days prior to exercise. Participants completed an eccentric exercise procedure of the elbow flexors at 140% of 1-RM (6 sets x 10 repetitions). The time under tension (TUT) for each set of eccentric contractions was recorded manually from the investigators voice commands. Fasted blood samples for prostaglandin E2 (PGE2), interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL1-ra), C-reactive protein and creatine kinase (CK) were assessed on days 1, 2 and 4. Fasted serum DHA was measured at baseline (day -28) and on day 1. Peak isometric strength of the elbow flexors, delayed-onset muscle soreness, and range of motion were measured on day 1 prior to exercise and days 2, 3, and 4 following exercise. Results: DHA significantly reduced natural log of CK (p<0.05) response over 4 d. Additionally, IL-6 area under the curve (AUC) was reduced for DHA compared to PL (3.6 ± 2.5 pg/mL vs. 5.3 ± 2.7 pg/mL) (p<0.05). TUT/set was higher in the DHA group compared to placebo (p<0.05). There were no other significant differences between treatments. Conclusion: DHA supplementation produced lower indicators of muscle damage (CK) and inflammation (IL-6 AUC). DHA supplementation resulted in greater TUT/set.