The effect of omega-3 fatty acids on a biomarker of head trauma in NCAA football athletes: a multi-site, non-randomized study.

BACKGROUND: American-style football (ASF) athletes are at risk for cardiovascular disease (CVD) and exhibit elevated levels of serum neurofilament light (Nf-L), a biomarker of axonal injury that is associated with repetitive head impact exposure over the course of a season of competition. Supplementation with the w-3 fatty acid (FA) docosahexaenoic acid (DHA) attenuates serum Nf-L elevations and improves aspects of CVD, such as the omega-3 index (O3I). However, the effect of combining the w-3 FA eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) with DHA on, specifically, serum Nf-L in ASF athletes is unknown. Therefore, this study assessed the effect of supplemental w-3 FA (EPA+DPA+DHA) on serum Nf-L, plasma w-3 FAs, the O3I, and surrogate markers of inflammation over the course of a season. METHODS: A multi-site, non-randomized design, utilizing two American football teams was employed. One team (n = 3 1) received supplementation with a highly bioavailablew-3 FA formulation (2000mg DHA, 560mg EPA, 320mg DPA, Mindset®, Struct Nutrition, Missoula, MT) during pre-season and throughout the regular season, while the second team served as the control (n = 35) and did not undergo supplementation. Blood was sampled at specific times throughout pre- and regular season coincident w ith changes in intensity, physical contact, and changes in the incidence and severity of head impacts. Group differences were determined via a mixed-model between-within subjects ANOVA. Effect sizes were calculated using Cohen's dfor all between-group differences. Significance was set a priori at p< .05. RESULTS: Compared to the control group, ASF athletes in the treatment group experienced large increases in plasma EPA (p < .001, d = 1.71) and DHA (p < .001, d = 2.10) which contributed to increases in the O3I (p < .001, d = 2.16) and the EPA:AA ratio (p = .001, d = 0.83) and a reduction in the w-6: w-3 ratio (p < .001, d = 1.80). w-3 FA supplementation attenuated elevations in Nf-L (p = .024). The control group experienced a significant increase in Nf-L compared to baseline at several measurement time points (T2, T3, and T4 [p range < .001 - .005, drange = 0.59-0.85]). CONCLUSIONS: These findings suggest a cardio- and neuroprotective effect of combined EPA+DPA+DHA w-3 FA supplementation in American-style football athletes. TRIAL REGISTRATION: This trial was registered with the ISRCTN registry ( ISRCTN90306741 ).

CSF and Blood Neurofilament Levels in Athletes Participating in Physical Contact Sports: A Systematic Review.

OBJECTIVE: To evaluate whether participating in physical contact sports is associated with a release of neurofilaments and whether such release is related to future clinical neurologic and/or psychiatric impairment. METHODS: We performed a systematic review of the PubMed, MEDLINE, and Cochrane Library databases using a combination of the search terms neurofilament(s)/intermediate filament and sport(s)/athletes. Original studies, written in English, reporting on neurofilaments in CSF and/or serum/plasma of contact sport athletes were included. This review was conducted following the Preferred Reporting Items for Systematic Review and Analyses guidelines. RESULTS: Eighteen studies in 8 different contact sports (i.e., boxing, American football, ice hockey, soccer, mixed martial arts, lacrosse, rugby, and wrestling) matched our criteria. Elevated light chain neurofilament (NfL) levels were described in 13/18 cohorts. Most compelling evidence was present in boxing and American football, where exposure-related increases were appreciable at the intraindividual level (up to 4.1- and 2.0-fold, respectively) in well-defined groups. Differences in exposure severity (including previous cumulative effects), sampling/measurement time points (with regard to expected peak values), and definitions of the baseline setting are considered as main contributors to the variability in findings. No studies were encountered that have investigated the relationship with the targeted clinical end points; therefore no NfL cutoffs exist that are associated with a poor outcome. CONCLUSION: NfL release can be seen, as a potential marker of neuronal brain damage, in participants of physical contact sports, particularly boxing and American football. The exact significance regarding the risk for future clinical impairment remains to be elucidated.

Vitamin D and athletes.

While it is well recognized that vitamin D is necessary for optimal bone health, emerging evidence is finding that adequate vitamin D intake reduces risk for conditions such as stress fracture, total body inflammation, infectious illness, and impaired muscle function. Studies in athletes have found that vitamin D status is variable and is dependent on outdoor training time (during peak sunlight), skin color, and geographic location. Although research has found that athletes generally do not meet the U.S. dietary reference intake for vitamin D, inadequate endogenous synthesis is the most probable reason for insufficient/deficient status. Given the recent findings, it is imperative that sports dietitians and physicians routinely assess vitamin D status and make recommendations to help athletes achieve a serum 25(OH)D concentration of >or=32 and preferably >or=40 ng.mL(-1). Further research is needed to determine the effect of vitamin D status on injury, training, and performance in athletes.

Effect of 830 nm low-level laser therapy applied before high-intensity exercises on skeletal muscle recovery in athletes.

Our aim was to investigate the immediate effects of bilateral, 830 nm, low-level laser therapy (LLLT) on high-intensity exercise and biochemical markers of skeletal muscle recovery, in a randomised, double-blind, placebo-controlled, crossover trial set in a sports physiotherapy clinic. Twenty male athletes (nine professional volleyball players and eleven adolescent soccer players) participated. Active LLLT (830 nm wavelength, 100 mW, spot size 0.0028 cm(2), 3-4 J per point) or an identical placebo LLLT was delivered to five points in the rectus femoris muscle (bilaterally). The main outcome measures were the work performed in the Wingate test: 30 s of maximum cycling with a load of 7.5% of body weight, and the measurement of blood lactate (BL) and creatine kinase (CK) levels before and after exercise. There was no significant difference in the work performed during the Wingate test (P > 0.05) between subjects given active LLLT and those given placebo LLLT. For volleyball athletes, the change in CK levels from before to after the exercise test was significantly lower (P = 0.0133) for those given active LLLT (2.52 U l(-1) +/- 7.04 U l(-1)) than for those given placebo LLLT (28.49 U l(-1) +/- 22.62 U l(-1)). For the soccer athletes, the change in blood lactate levels from before exercise to 15 min after exercise was significantly lower (P < 0.01) in the group subjected to active LLLT (8.55 mmol l(-1) +/- 2.14 mmol l(-1)) than in the group subjected to placebo LLLT (10.52 mmol l(-1) +/- 1.82 mmol l(-1)). LLLT irradiation before the Wingate test seemed to inhibit an expected post-exercise increase in CK level and to accelerate post-exercise lactate removal without affecting test performance. These findings suggest that LLLT may be of benefit in accelerating post-exercise recovery.

Effects of intermittent exposure to hyperbaric oxygen for the treatment of an acute soft tissue injury.

OBJECTIVE: To assess the hypothesis that subjects exposed to intermittent hyperbaric oxygen treatments would recover from signs and symptoms indicative of delayed-onset muscle soreness faster than subjects exposed to normoxic air. DESIGN: Randomized, double-blinded study with a 4-day treatment protocol. SETTING: University-based sports medicine clinic. PARTICIPANTS: Sixteen sedentary female university students. INTERVENTIONS: All subjects performed 300 maximal voluntary eccentric contractions (30 sets of 10 repetitions per minute) of their nondominant leg (110 to 35 degrees of knee flexion) at a slow speed (30 degrees per second) on a dynamometer to elicit muscle damage and injury. Hyperbaric oxygen treatments consisted of 100% oxygen for 60 minutes at 2.0 atmospheres absolute (ATA), while the control group received 21% oxygen at 1.2 ATA for the same amount of time. Both groups received treatment immediately after the induction of delayed-onset muscle soreness and each day thereafter for a period of 4 days (day 1 postexercise through day 4 postexercise). MAIN OUTCOME MEASURES: Dependent variables (perceived muscle soreness, isokinetic strength, quadriceps circumference, creatine kinase, and malondialdehyde) were assessed at baseline (preexercise, day 0), 4 hours postexercise (day 1), 24 hours postexercise (day 2), 48 hours postexercise (day 3), and 72 hours postexercise (day 4). Magnetic resonance images (T2 relaxation time/short tip inversion recovery) were assessed at baseline (day 0), 24 hours postexercise (day 3), and 72 hours postexercise (day 5). RESULTS: Repeated-measures analysis of variance was performed on all of the dependent variables to assess differences between treatment and control groups. Analyses revealed no significant differences between groups for treatment effects for any of the dependent variables (pain, strength, quadriceps circumference, creatine kinase, malondialdehyde, or magnetic resonance images). CONCLUSIONS: The findings of this study suggest that hyperbaric oxygen therapy is not effective in the treatment of exercise-induced muscle injury as indicated by the markers evaluated.

Effects of huangqi jianzhong tang on hematological and biochemical parameters in judo athletes.

AIM: The purpose of the study was to investigate the effects of Huangqi Jianzhong Tang (HQJZT) on hematological and biochemical parameters in judo athletes. METHODS: Sixteen male and eight female judo athletes in Hsin-Ming senior high school were randomly and stratified divided into control and experimental group, which received placebo and HQJZT respectively during the five-week training program. The measurement of the hematological and biochemical parameters was performed twice, just before and after the training. The data was analyzed with paired-t test and ANOVA. RESULTS: The values of RBC, Hb, and Hct were obvious decreased after intervention, while the value of GOT, GPT, BUN, and CK was elevated. CONCLUSION: The results indicated the hematological and biochemical changes were caused by the physical training but not the effects of HQJZT. The HQJZT had no adverse effects on the judo athletes in our study.