promoting recovery from muscle damaging exercise ( Pasiakos et al., 2014 ). Given the anti-inflammatory properties of long chain n-3 polyunsaturated fatty acids (n-3PUFA) ( DiLorenzo et al., 2014 ), an alternative nutritional strategy is dietary supplementation with fish oil–derived n-3PUFA ( Gray et
Jordan D. Philpott, Chris Donnelly, Ian H. Walshe, Elizabeth E. MacKinley, James Dick, Stuart D.R. Galloway, Kevin D. Tipton and Oliver C. Witard
Patrick Gray, Andrew Chappell, Alison McE Jenkinson, Frank Thies and Stuart R. Gray
Due to the potential anti-inflammatory properties of fish-derived long chain n-3 fatty acids, it has been suggested that athletes should regularly consume fish oils—although evidence in support of this recommendation is not clear. While fish oils can positively modulate immune function, it remains possible that, due to their high number of double bonds, there may be concurrent increases in lipid peroxidation. The current study aims to investigate the effect of fish oil supplementation on exercise-induced markers of oxidative stress and muscle damage. Twenty males underwent a 6-week double-blind randomized placebo-controlled supplementation trial involving two groups (fish oil or placebo). After supplementation, participants undertook 200 repetitions of eccentric knee contractions. Blood samples were taken presupplementation, postsupplementation, immediately, 24, 48, and 72 hr postexercise and muscle soreness/maximal voluntary contraction (MVC) assessed. There were no differences in creatine kinase, protein carbonyls, endogenous DNA damage, muscle soreness or MVC between groups. Plasma thiobarbituric acid reactive substances (TBARS) were lower (p < .05) at 48 and 72 hr post exercise and H2O2 stimulated DNA damage was lower (p < .05) immediately postexercise in the fish oil, compared with the control group. The current study demonstrates that fish oil supplementation reduces selected markers of oxidative stress after a single bout of eccentric exercise.
Vinicius Coneglian Santos, Adriana Cristina Levada-Pires, Sâmia Rocha Alves, Tânia Cristina Pithon-Curi, Rui Curi and Maria Fernanda Cury-Boaventura
To investigate the effects of docosahexaenoic-(DHA)-rich fish oil (FO) supplementation on lymphocyte function before and after a marathon race.
Twenty-one athletes participated in this study. Eight marathon runners were supplemented with 3 g of FO daily for 60 d (FO group), and 13 athletes were not supplemented (C group). The following measures of lymphocytes were taken before and after the marathon: cell proliferation, cytokine production (IL-2, IL-10, TNF-α, and IL-4), and signs of cell death.
In the C group, the marathon had no effect on lymphocyte proliferation, DNA fragmentation, or mitochondrial membrane polarization; however, the marathon increased phosphatidylserine externalization (by 2.5-fold), induced a loss of plasma membrane integrity (by 20%), and decreased IL-2, TNF-α, and IL-10 production (by 55%, 95%, and 50%, respectively). FO supplementation did not prevent lymphocyte death induced by the marathon, as indicated by cell viability, DNA fragmentation, and phosphatidylserine externalization. However, FO supplementation increased lymphocyte proliferation before and after the marathon, and before the race, FO supplementation decreased IL-2, TNF-α, and IL-10 production in concanavalin-A-stimulated lymphocytes (by 55%, 95%, and 58%, respectively) compared with cells from the C group. The production of cytokines was not altered before or after the race in the FO group.
DHA-rich FO supplementation increased lymphocyte proliferation and prevented a decrease in cytokine production, but it did not prevent lymphocyte death induced by participation in the marathon. Overall, DHA rich-FO supplementation has beneficial effects in preventing some of the changes in lymphocyte function induced by marathon participation.
Lachlan Hingley, Michael J. Macartney, Marc A. Brown, Peter L. McLennan and Gregory E. Peoples
Dietary fish oil, providing docosahexaenoic acid (DHA) modulates oxygen consumption and fatigue in animal models. However, in humans predominately supplemented with high eicosapentaenoic acid (EPA), there is no evidence of endurance performance enhancement. Therefore, this study examined if DHA-rich fish oil could improve repeated bouts of physiologically stressful cycling and a subsequent time trial in a state of fatigue. Twenty-six trained males took part in a double-blind study and were supplemented with either 2 × 1g/day soy oil, Control) or DHA-rich tuna fish oil (Nu-Mega) (FO) (560mg DHA / 140mg eicosapentaenoic acid (EPA), for 8 weeks. Maximal cycling power (3 × 6s), isometric quadriceps strength (MVC), Wingate cycling protocol (6 × 30s) and a 5min cycling time-trial were assessed at baseline and eight weeks. The Omega-3 Index was not different at baseline (Control: 4.2 ± 0.2; FO: 4.7 ± 0.2%) and increased in the FO group after eight weeks (Control: 3.9 ± 0.2; FO: 6.3 ± 0.3%, p < .01). There was no effect of DHA-rich fish oil on power output of maximal 6s cycle sprinting (Control: Pre 1100 ± 49 Post 1067 ± 51; FO: Pre 1070 ± 46 Post 1042 ± 46W), during 5min time trail (Control: Pre 267 ± 19 Post 278 ± 20; FO: Pre 253 ± 16 Post 265 ± 16 W) or maximal voluntary contraction force (Control: Pre 273 ± 19 Post 251 ± 19; FO: Pre 287 ± 17 Post 283 ± 16 Nm). Nevertheless, relative oxygen consumption was reduced the FO group during the cycling time trial (Control: -23 ± 26; FO: -154 ± 59ml O2/min/100W p < .05) suggesting improved economy of cycling. We conclude that DHA-rich fish oil, successful at elevating the Omega-3 Index, and reflective of skeletal muscle membrane incorporation, can modulate oxygen consumption during intense exercise.
Timothy D. Mickleborough
Increased muscle oxidative stress and inflammatory responses among athletes have been reported consistently. In addition, it is well known that exhaustive or unaccustomed exercise can lead to muscle fatigue, delayed-onset muscle soreness, and a decrement in performance. Omega-3 polyunsaturated fatty acids (PUFAs) have been shown to decrease the production of inflammatory eicosanoids, cytokines, and reactive oxygen species; have immunomodulatory effects; and attenuate inflammatory diseases. While a number of studies have assessed the efficacy of omega-3 PUFA supplementation on red blood cell deformability, muscle damage, inflammation, and metabolism during exercise, only a few have evaluated the impact of omega-3 PUFA supplementation on exercise performance. It has been suggested that the ingestion of EPA and DHA of approximately 1–2 g/d, at a ratio of EPA to DHA of 2:1, may be beneficial in counteracting exercise-induced inflammation and for the overall athlete health. However, the human data are inconclusive as to whether omega-3 PUFA supplementation at this dosage is effective in attenuating the inflammatory and immunomodulatory response to exercise and improving exercise performance. Thus, attempts should be made to establish an optimal omega-3 fatty-acid dosage to maximize the risk-to-reward ratio of supplementation. It should be noted that high omega-3 PUFA consumption may lead to immunosuppression and prolong bleeding time. Future studies investigating the efficacy of omega-3 PUFA supplementation in exercise-trained individuals should consider using an exercise protocol of sufficient duration and intensity to produce a more robust oxidative and inflammatory response.
Marco Malaguti, Marta Baldini, Cristina Angeloni, Pierluigi Biagi and Silvana Hrelia
The authors evaluated the role of a high-protein, low-calorie, polyunsaturated fatty-acid (PUFA) -supplemented diet on anthropometric parameters, erythrocytemembrane fatty-acid composition, and plasma antioxidant defenses of nonprofessional volleyball athletes. The athletes were divided in two groups: One (n = 5) followed the Mediterranean diet, and the other (n = 6) followed a high-protein, low-calorie diet with a 3-g/day fish-oil supplementation. All the athletes had anthropometric measurements taken, both at the beginning and at the end of the study, which lasted for 2 months. Body-mass index and total body fat were significantly diminished in the second group, while they remained unchanged in the first. Plasma total antioxidant activity (TAA) was significantly increased in the plasma of both groups, with no differences between the groups, suggesting that physical activity, not the different diets, is the main contributor to the increase of plasma TAA. The second group showed a significant increase in erythrocytemembrane PUFA content and in the unsaturation index value (UI) because of the fish-oil supplementation. A high-protein, low-carbohydrate, fish-oil-supplemented diet seems to be useful only when the aim of the diet is to obtain weight loss in a short-term period. The significant increase in the UI of erythrocyte membranes indicates the potential for harm, because a high intake of PUFA might increase susceptibility to lipid peroxidation not counterbalanced by a higher increase in TAA. Adherence to the Mediterranean diet seems to be the better choice.
David C. Nieman, Dru A. Henson, Steven R. McAnulty, Fuxia Jin and Kendra R. Maxwell
The purpose of this study was to test the influence of 2.4 g/d fish oil n-3 polyunsaturated fatty acids (n-3 PUFA) over 6 wk on exercise performance, inflammation, and immune measures in 23 trained cyclists before and after a 3-d period of intense exercise. Participants were randomized to n-3 PUFA (n = 11; 2,000 mg eicosapentaenoic acid [EPA], 400 mg docosahexaenoic acid [DHA]) or placebo (n = 12) groups. They ingested supplements under double-blind methods for 6 wk before and during a 3-d period in which they cycled for 3 hr/d at ~57% Wmax with 10-km time trials inserted during the final 15 min of each 3-hr bout. Blood and saliva samples were collected before and after the 6-wk supplementation period, immediately after the 3-hr exercise bout on the third day, and 14 hr postexercise and analyzed for various immune-function and inflammation parameters. Supplementation with n-3 PUFA resulted in a significant increase in plasma EPA and DHA but had no effect on 10-km time-trial performance; preexercise outcome measures; exercise-induced increases in plasma cytokines, myeloperoxidase, blood total leukocytes, serum C-reactive protein, and creatine kinase; or the decrease in the salivary IgA:protein ratio. In conclusion, 6 wk supplementation with a large daily dose of n-3 PUFAs increased plasma EPA and DHA but had no effect on exercise performance or in countering measures of inflammation and immunity before or after a 3-d period of 9 hr of heavy exertion.
Julien Louis, Fabrice Vercruyssen, Olivier Dupuy and Thierry Bernard
synthesis and avoid muscle protein catabolism, respectively, especially during the immobilization and rehabilitation phase ( Hespel et al., 2001 ; Wilkinson et al., 2013 ). Recently, attention has also been brought to the potential of fish-oil–derived omega-3 fatty acids to increase postexercise muscle
Eric S. Rawson, Mary P. Miles and D. Enette Larson-Meyer
preservation of lean mass in older adults ingesting HMB during 10 days of bed rest. Omega-3 Fatty Acids Omega-3 polyunsaturated fatty acids are essential fatty acids that are consumed in the diet and concentrated in foods such as cold-water fatty fish and fish oils. Fish oil and, in particular
promise as an efficacious intervention that could benefit EIMD in older adults and warrants exploration in future studies. Another supplement that has recently shown positive effects on EIMD in young adults and aged muscle in general is fish-oil-derived omega-3 fatty acids. Indeed, studies have shown that