ω-3 fatty acid supplementation as a potential therapeutic aid for the recovery from mild traumatic brain injury/concussion

n-3 PUFA ameliorate functional outcomes following repetitive mTBI in the fat-1 mouse model

Purpose

Repeated mild traumatic brain injuries (mTBI) are a continuing healthcare concern worldwide, given its potential for enduring adverse neurodegenerative conditions. Past research suggests a potential protective effect of n-3 polyunsaturated fatty acids (PUFA) in experimental models of mTBI. The aim of this study was to investigate whether the neuroprotective benefits of n-3 PUFA persist following repetitive weight drop injury (WDI).

Methods

Male fat-1 mice (n = 12), able to endogenously convert n-6 PUFA to n-3 PUFA, and their wild type (WT) counterparts (n = 12) were maintained on a 10% w/w safflower diet. At 9-10 weeks of age, both groups received one mild low-impact WDI on the closed cranium daily, for three consecutive days. Following each WDI, time to righting reflex and seeking behaviour were measured. Neurological recovery, cognitive, motor, and neurobehavioural outcomes were assessed using the Neurological Severity Score (NSS) over 7 days (168 h) post-last WDI. Brains were assessed for cerebral microhemorrhages by Prussian blue and cellular damage by glial fibrillary acidic protein (GFAP) staining.

Results

Fat-1 mice exhibited significantly faster righting reflex and seeking behaviour time, and lower mean NSS scores and at all post-WDI time points (p ≤ 0.05) compared to WT mice. Immunohistochemistry showed no significant difference in presence of cerebral microhemorrhage however, fat-1 mice had significantly lower GFAP staining in comparison to WT mice (p ≤ 0.05).

Conclusion

n-3 PUFA is effective in restoring cognitive, motor, and behavioural function after repetitive WDI, which may be mediated through reduced cellular damage of the brain.

What are the Protocols and Resources for Sport-Related Concussion Among Top National Collegiate Athletic Association Football Programs? A Cross-Sectional Survey of A5 Schools

OBJECTIVE

This study summarizes findings from a cross-sectional survey conducted among National Collegiate Athletic Association (NCAA) Division 1 football programs, focusing on sport-related concussion (SRC) protocols for the 2018 season.

DESIGN

Cross-sectional survey study.

SETTING

65 football programs within the Autonomy Five (A5) NCAA conferences.

PARTICIPANTS

Athletic trainers and team physicians who attended a football safety meeting at the NCAA offices June 17 to 18, 2019, representing their respective institutions.

INTERVENTION

Electronic surveys were distributed on June 14, 2019, before the football safety meeting.

MAIN OUTCOME MEASURES

Results for 16 unique questions involving SRC protocols and resources were summarized and evaluated.

RESULTS

The survey garnered responses from 46 of 65 programs (response rate = 71%). For baseline testing, 98% measured baseline postural stability and balance, 87% used baseline neurocognitive testing, while only 61% assessed baseline vestibular and/or ocular function. Regarding concussion prevention, 51% did not recommend additional measures, while 4% and 24% recommended cervical compression collars and omega-3 supplementation, respectively. In postconcussion treatment, 26% initiated aerobic exercise 1 day postconcussion if symptoms were stable, 24% waited at least 48 hours, 4% waited for the athlete to return to baseline, 11% waited until the athlete became asymptomatic, and 35% determined procedures on a case-by-case basis.

CONCLUSIONS

Most institutions assessed postural stability/balance and neurocognitive functioning at baseline and introduced light aerobic exercise within 48 h postconcussion. There was variation in baseline assessment methods and concussion prevention recommendations. These survey findings deepen our understanding of diverse SRC protocols in NCAA football programs.

Impact of fish oil supplementation on plasma levels of highly unsaturated fatty acid-containing lipid classes and molecular species in American football athletes

BACKGROUND

Previous studies have linked sports-related concussions and repeated subconcussive head impacts in contact sport athletes to elevated brain injury biomarkers. Docosahexaenoic acid (DHA), the primary omega-3 (n-3) highly unsaturated fatty acid (HUFA) in the brain, has shown neuroprotective effects in animal models after brain injury, but clinical research has shown mixed results.

METHODS

We conducted a randomized, double-blind, placebo-controlled study on 29 Division 1 collegiate American football players, exploring the impact of DHA (2.5 g) and eicosapentaenoic acid (EPA) (1.0 g) supplied as ethyl esters, on levels of plasma lipids shown to cross the blood-brain barrier. Dietary intake data was collected using food frequency questionnaires (FFQ). Complex lipids and unesterified fatty acids were isolated from plasma, separated via reversed-phase liquid chromatography and analyzed by targeted lipidomics analysis.

RESULTS

FFQ results indicated that participants had low dietary n-3 HUFA intake and high omega-6 (n-6):n-3 polyunsaturated fatty acids (PUFA) and HUFA ratios at baseline. After DHA + EPA supplementation, plasma lysophosphatidylcholine (LPC) containing DHA and EPA significantly increased at all timepoints (weeks 17, 21, and 26; p < 0.0001), surpassing placebo at Weeks 17 (p < 0.05) and 21 (p < 0.05). Phosphatidylcholine (PC) molecular species containing DHA or EPA, PC38:6 PC36:6, PC38:7, PC40:6, and PC40:8, increased significantly in the DHA + EPA treatment group at Weeks 17 (and 21. Plasma concentrations of non-esterified DHA and EPA rose post-supplementation in Weeks 17 and 21.

CONCLUSIONS

This study demonstrates that n-3 HUFA supplementation, in the form of ethyl esters, increased the DHA and EPA containing plasma lipid pools the have the capacity to enrich brain lipids and the potential to mitigate the effects of sports-related concussions and repeated subconcussive head impacts.

TRIAL REGISTRATION

All deidentified data are available at ClinicalTrials.gov #NCT0479207.

Time-Dependent Long-Term Effect of Memantine following Repetitive Mild Traumatic Brain Injury

Repetitive mild traumatic brain injury (rmTBI, e.g., sports concussions) may be associated with both acute and chronic symptoms and neurological changes. Despite the common occurrence of these injuries, therapeutic strategies are limited. One potentially promising approach is N-methyl-D-aspartate receptor (NMDAR) blockade to alleviate the effects of post-injury glutamatergic excitotoxicity. Initial pre-clinical work using the NMDAR antagonist, memantine, suggests that immediate treatment following rmTBI improves a variety of acute outcomes. It remains unclear (1) whether acute memantine treatment has long-term benefits and (2) whether delayed treatment following rmTBI is beneficial, which are both clinically relevant concerns. To test this, animals were subjected to rmTBI via a weight drop model with rotational acceleration (five hits in 5 days) and randomized to memantine treatment immediately, 3 months, or 6 months post-injury, with a treatment duration of one month. Behavioral outcomes were assessed at 1, 4, and 7 months post-injury. Neuropathological outcomes were characterized at 7 months post-injury. We observed chronic changes in behavior (anxiety-like behavior, motor coordination, spatial learning, and memory), as well as neuroinflammation (microglia, astrocytes) and tau phosphorylation (T231). Memantine treatment, either immediately or 6 months post-injury, appears to confer greater rescue of neuroinflammatory changes (microglia) than vehicle or treatment at the 3-month time point. Although memantine is already being prescribed chronically to address persistent symptoms associated with rmTBI, this study represents the first evidence of which we are aware to suggest a small but durable effect of memantine treatment in mild, concussive injuries. This effect suggests that memantine, although potentially beneficial, is insufficient to treat all aspects of rmTBI alone and should be combined with other therapeutic agents in a multi-therapy approach, with attention given to the timing of treatment.

The Physiological Requirements of and Nutritional Recommendations for Equestrian Riders

Equestrian sport is under-researched within the sport science literature, creating a possible knowledge vacuum for athletes and support personnel wishing to train and perform in an evidence-based manner. This review aims to synthesise available evidence from equitation, sport, and veterinary sciences to describe the pertinent rider physiology of equestrian disciplines. Estimates of energy expenditure and the contribution of underpinning energy systems to equestrian performance are used to provide nutrition and hydration recommendations for competition and training in equestrian disciplines. Relative energy deficiency and disordered eating are also considered. The practical challenges of the equestrian environment, including competitive, personal, and professional factors, injury and concussion, and female participation, are discussed to better highlight novelty within equestrian disciplines compared to more commonly studied sports. The evidence and recommendations are supported by example scenarios, and future research directions are outlined.

Towards early detection of neurodegenerative diseases: A gut feeling

The gastrointestinal tract communicates with the nervous system through a bidirectional network of signaling pathways called the gut-brain axis, which consists of multiple connections, including the enteric nervous system, the vagus nerve, the immune system, endocrine signals, the microbiota, and its metabolites. Alteration of communications in the gut-brain axis is emerging as an overlooked cause of neuroinflammation. Neuroinflammation is a common feature of the pathogenic mechanisms involved in various neurodegenerative diseases (NDs) that are incurable and debilitating conditions resulting in progressive degeneration and death of neurons, such as in Alzheimer and Parkinson diseases. NDs are a leading cause of global death and disability, and the incidences are expected to increase in the following decades if prevention strategies and successful treatment remain elusive. To date, the etiology of NDs is unclear due to the complexity of the mechanisms of diseases involving genetic and environmental factors, including diet and microbiota. Emerging evidence suggests that changes in diet, alteration of the microbiota, and deregulation of metabolism in the intestinal epithelium influence the inflammatory status of the neurons linked to disease insurgence and progression. This review will describe the leading players of the so-called diet-microbiota-gut-brain (DMGB) axis in the context of NDs. We will report recent findings from studies in model organisms such as rodents and fruit flies that support the role of diets, commensals, and intestinal epithelial functions as an overlooked primary regulator of brain health. We will finish discussing the pivotal role of metabolisms of cellular organelles such as mitochondria and peroxisomes in maintaining the DMGB axis and how alteration of the latter can be used as early disease makers and novel therapeutic targets.

A Pilot Randomized Controlled Trial of Docosahexaenoic Acid for the Treatment of Sport-Related Concussion in Adolescents

The objective was to examine the use of docosahexaenoic acid (DHA) for the treatment of sport-related concussion (SRC) in adolescent athletes. We hypothesize that participants who intake 2 g of DHA daily will not experience differences in recovery compared with participants who take a placebo. This double-blind, randomized controlled pilot trial was performed in a tertiary pediatric sports medicine clinic from 2013 to 2017 in adolescents (14-18 years) presenting with diagnosed SRC within 4 days of injury. Forty participants were randomized into DHA or PLACEBO group and were instructed to take 2 capsules twice daily for 12 weeks. Participants in the DHA group were symptom-free earlier than the PLACEBO group (11.0 vs 16.0 days, P = .08) and were cleared to begin the Return to Sport progression (14.0 vs 19.5 days, P = .12) sooner. The use of 2 g/day of DHA was well-tolerated and did not significantly affect recovery times in adolescent athletes following SRC.Clinical Trial Registration: ClincalTrials.gov, NCT01903525.

Nutritional interventions to support acute mTBI recovery

When mild traumatic brain injury (mTBI) occurs following an impact on the head or body, the brain is disrupted leading to a series of metabolic events that may alter the brain's ability to function and repair itself. These changes may place increased nutritional demands on the body. Little is known on whether nutritional interventions are safe for patients to implement post mTBI and whether they may improve recovery outcomes. To address this knowledge gap, we conducted a systematic review to determine what nutritional interventions have been prescribed to humans diagnosed with mTBI during its acute period (<14 days) to support, facilitate, and result in measured recovery outcomes.

Methods

Databases CINAHL, PubMed, SPORTDiscus, Web of Science, and the Cochrane Library were searched from inception until January 6, 2021; 4,848 studies were identified. After removing duplicates and applying the inclusion and exclusion criteria, this systematic review included 11 full papers.

Results

Patients that consumed enough food to meet calorie and macronutrient (protein) needs specific to their injury severity and sex within 96 h post mTBI had a reduced length of stay in hospital. In addition, patients receiving nutrients and non-nutrient support within 24-96 h post mTBI had positive recovery outcomes. These interventions included omega-3 fatty acids (DHA and EPA), vitamin D, mineral magnesium oxide, amino acid derivative N-acetyl cysteine, hyperosmolar sodium lactate, and nootropic cerebrolysin demonstrated positive recovery outcomes, such as symptom resolution, improved cognitive function, and replenished nutrient deficiencies (vitamin D) for patients post mTBI.

Conclusion

Our findings suggest that nutrition plays a positive role during acute mTBI recovery. Following mTBI, patient needs are unique, and this review presents the potential for certain nutritional therapies to support the brain in recovery, specifically omega-3 fatty acids. However, due to the heterogenicity nature of the studies available at present, it is not possible to make definitive recommendations.

Systematic review registration

The systematic review conducted following the PRISMA guidelines protocol was registered (CRD42021226819), on Prospero.

Neuro-Inflammation Modulation and Post-Traumatic Brain Injury Lesions: From Bench to Bed-Side

Head trauma is the most common cause of disability in young adults. Known as a silent epidemic, it can cause a mosaic of symptoms, whether neurological (sensory-motor deficits), psychiatric (depressive and anxiety symptoms), or somatic (vertigo, tinnitus, phosphenes). Furthermore, cranial trauma (CT) in children presents several particularities in terms of epidemiology, mechanism, and physiopathology-notably linked to the attack of an immature organ. As in adults, head trauma in children can have lifelong repercussions and can cause social and family isolation, difficulties at school, and, later, socio-professional adversity. Improving management of the pre-hospital and rehabilitation course of these patients reduces secondary morbidity and mortality, but often not without long-term disability. One hypothesized contributor to this process is chronic neuroinflammation, which could accompany primary lesions and facilitate their development into tertiary lesions. Neuroinflammation is a complex process involving different actors such as glial cells (astrocytes, microglia, oligodendrocytes), the permeability of the blood-brain barrier, excitotoxicity, production of oxygen derivatives, cytokine release, tissue damage, and neuronal death. Several studies have investigated the effect of various treatments on the neuroinflammatory response in traumatic brain injury in vitro and in animal and human models. The aim of this review is to examine the various anti-inflammatory therapies that have been implemented.

Defining Biological Phenotypes of Mild Traumatic Brain Injury Using Saliva MicroRNA Profiles

Concussion is a heterogeneous injury that relies predominantly on subjective symptom reports for patient assessment and treatment. Developing an objective, biological test could aid phenotypic categorization of concussion patients, leading to advances in personalized treatment. This prospective multi-center study employed saliva micro-ribonucleic acid (miRNA) levels to stratify 251 individuals with concussion into biological subgroups. Using miRNA biological clusters, our objective was to assess for differences in medical/demographic characteristics, symptoms, and functional measures of balance and cognition. The miRNAs that best defined each cluster were used to identify physiological pathways that characterized each cluster. The 251 participants (mean age: 18 ± 7 years; 57% male) were optimally grouped into 10 clusters based on 22 miRNA levels. The clusters differed in age (χ2 = 19.1, p = 0.024), days post-injury at the time of saliva collection (χ2 = 22.6; p = 0.007), and number of prior concussions (χ2 = 17.6, p = 0.040). The clusters also differed in symptom reports for fatigue (χ2 = 17.7; p = 0.039), confusion (χ2 = 22.3; p = 0.008), difficulty remembering (χ2 = 22.0; p = 0.009), and trouble falling asleep (χ2 = 17.2; p = 0.046), but not objective balance or cognitive performance (p > 0.05). The miRNAs that defined concussion clusters regulate 16 physiological pathways, including adrenergic signaling, estrogen signaling, fatty acid metabolism, GABAergic signaling, synaptic vesicle cycling, and transforming growth factor (TGF)-β signaling. These results show that saliva miRNA levels may stratify individuals with concussion based on underlying biological perturbations that are relevant to both symptomology and pharmacological targets. If validated in a larger cohort, miRNA assessment could aid individualized, biology-driven concussion treatment.

Nutritional Considerations for Injury Prevention and Recovery in Combat Sports

Sports participation is not without risk, and most athletes incur at least one injury throughout their careers. Combat sports are popular all around the world, and about one-third of their injuries result in more than 7 days of absence from competition or training. The most frequently injured body regions are the head and neck, followed by the upper and lower limbs, while the most common tissue types injured are superficial tissues and skin, followed by ligaments and joint capsules. Nutrition has significant implications for injury prevention and enhancement of the recovery process due to its effect on the overall physical and psychological well-being of the athlete and improving tissue healing. In particular, amino acid and protein intake, antioxidants, creatine, and omega-3 are given special attention due to their therapeutic roles in preventing muscle loss and anabolic resistance as well as promoting injury healing. The purpose of this review is to present the roles of various nutritional strategies in reducing the risk of injury and improving the treatment and rehabilitation process in combat sports. In this respect, nutritional considerations for muscle, joint, and bone injuries as well as sports-related concussions are presented. The injury risk associated with rapid weight loss is also discussed. Finally, preoperative nutrition and nutritional considerations for returning to a sport after rehabilitation are addressed.

Dietary lipids from body to brain

Dietary habits have drastically changed over the last decades in Western societies. The Western diet, rich in saturated fatty acids (SFA), trans fatty acids (TFA), omega-6 polyunsaturated fatty acids (n-6 PUFA) and cholesterol, is accepted as an important factor in the development of metabolic disorders, such as obesity and diabetes type 2. Alongside these diseases, nutrition is associated with the prevalence of brain disorders. Although clinical and epidemiological studies revealed that metabolic diseases and brain disorders might be related, the underlying pathology is multifactorial, making it hard to determine causal links. Neuroinflammation can be a result of unhealthy diets that may cause alterations in peripheral metabolism. Especially, dietary fatty acids are of interest, as they act as signalling molecules responsible for inflammatory processes. Diets rich in n-6 PUFA, SFA and TFA increase neuroinflammation, whereas diets rich in monounsaturated fatty acids (MUFA), omega-3 (n-3) PUFA and sphingolipids (SL) can diminish neuroinflammation. Moreover, these pro- and anti-inflammatory diets might indirectly influence neuroinflammation via the adipose tissue, microbiome, intestine and vasculature. Here, we review the impact of nutrition on brain health. In particular, we will discuss the role of dietary lipids in signalling pathways directly applicable to inflammation and neuronal function.

Management of Concussion and Persistent Post-Concussive Symptoms for Neurologists

PURPOSE OF REVIEW

Concussion is a complex injury that may present as a variety of clinical profiles, which can overlap and reinforce one another. This review summarizes the medical management of patients with concussion and persistent post-concussive symptoms (PPCS).

RECENT FINDINGS

Management of concussion and PPCS relies on identifying underlying symptom generators. Treatment options include sub-symptom threshold aerobic exercise, cervical physical therapy, vestibular therapy, vision therapy, cognitive rehabilitation, cognitive behavioral therapy, pharmacological management, or a combination of treatments. Evidence-based treatments have emerged to treat post-concussion symptom generators for sport-related concussion and for patients with PPCS.

N-3 Polyunsaturated Fatty Acids Ameliorate Neurobehavioral Outcomes Post-Mild Traumatic Brain Injury in the Fat-1 Mouse Model

Concussions and mild traumatic brain injury (m-TBI) have been identified as a consequential public health concern because of their potential to cause considerable impairments in physical, cognitive, behavioral, and social functions. Given their prominent structural and functional roles in the brain, n-3 polyunsaturated fatty acids (PUFA) have been identified as a potentially viable prophylactic agent that may ameliorate the deleterious effects of m-TBI on brain function. The purpose of the present pilot study was to investigate the effect of n-3 PUFA on neurologic function using a weight drop injury (WDI) model. Fat-1 mice, capable of synthesizing n-3 PUFA endogenously from n-6 PUFA, and their wild-type (WT) counterparts, were subjected to a mild low-impact WDI on the closed cranium, and recovery was evaluated using the neurological severity score (NSS) to assess the motor and neurobehavioral outcomes. In comparison to the WT mice, the fat-1 mice had a significantly (p ≤ 0.05) lower NSS at all time points post-WDI, and significantly greater neurological restoration measured as the time to first movement. Overall, these findings demonstrate the protective effect of n-3 PUFA against mild brain injury.

Molecular Deficits Relevant to Concussion Are Prevalent in Top-Ranked Football Players Entering the National Football League Draft

ABSTRACT

Kunces, LJ, Keenan, J, Schmidt, CM, and Schmidt, MA. Molecular deficits relevant to concussion are prevalent in top-ranked football players entering the National Football League draft. J Strength Cond Res XX(X): 000-000, 2021-Characterization of blood variants in athletes entering the highly competitive contact environment of professional football can help us understand the risk for brain injury. When coupled with longitudinal follow-up of future concussion incidence and trajectory, it may provide additional insight into factors that influence brain injury. We observed the metabolic phenotype of collegiate football players entering the 2016 National Football League (NFL) draft. The principal aims were to characterize the molecular status of individual athletes and quantify the prevalence of athletes with multiple concurrent molecular deficits. Blood was taken from 30 elite American collegiate football players 7 weeks before the NFL scouting combine and 15 weeks before entering the NFL draft. Average results revealed suboptimal values in Omega-3 Index (avg ± std, 4.66 ± 1.16%), arachidonic acid:eicosapentaenoic acid fatty acid ratio (29.13 ± 10.78), homocysteine (11.4 ± 3.4 µmol·L-1), vitamin D (30 ± 11.4 ng·ml-1), and red blood cell magnesium (4.1 ± 0.8 mg·dl-1). Using sport-optimized reference ranges from previously published research, 10% presented with 3, 40% presented with 4, and 50% of athletes presented with 5 suboptimal values at once. We conclude molecular deficits in this cohort entering the NFL draft were common, with a significant number of athletes presenting with multiple suboptimal levels. The significant commonality of the suboptimal biomarkers is relevance to brain health and function. This data warrant extensive metabolic phenotyping and consideration of prophylactic precision nutrition countermeasures by the multidisciplinary staff for athletes entering contact environments.

Concussion in the Athletic Training Room: a Team Physician Narrative

PURPOSE OF THE REVIEW

Concussion evaluation and management has changed significantly. Understanding proper recognition, evaluation, and management allows for improved provision of care to patients. This paper will approach this topic from a sideline to training room management versus the traditional clinic evaluation RECENT FINDINGS: Research is continuing to refine and examine tools to assist in proper concussion evaluation. Concussion recovery protocols are becoming more conservative as patients are taking longer to recover than previously thought. Treatment of concussion is becoming more sophisticated and patient involved. Concussion research has increased dramatically over the last 30 years changing our approach to diagnosis and treatment. The area of concussion will continue to evolve as research continues to look at effective tools and markers for diagnosis and effective treatment protocols become substantiated through research.

Rehabilitation of Concussion and Persistent Postconcussive Symptoms

Concussion and persistent postconcussive symptoms (PPCS) are encountered by clinicians in sports medicine, pediatrics, neurology, physiatry, emergency medicine, and primary care. Clinical management may require a multidisciplinary approach. This article presents a structured method for the diagnosis of concussion and PPCS in the outpatient setting, which includes a history, physical examination, and additional tests as clinically indicated to help identify underlying symptom generators. Treatment for concussion and PPCS should be individualized, based on predominant signs and symptoms, and can include subsymptom threshold aerobic exercise, cervical physical therapy, vestibulo-ocular rehabilitation, behavioral and cognitive psychotherapy, and some symptom-specific pharmacological therapies.

Nutritional Considerations and Strategies to Facilitate Injury Recovery and Rehabilitation

Nutritional interventions are not commonly a standard of care in rehabilitation interventions. A nutritional approach has the potential to be a low-cost, high-volume strategy that complements the existing standard of care. In this commentary, our aim is to provide an evidence-based, practical guide for athletes with injuries treated surgically or conservatively, along with healing and rehabilitation considerations. Injuries are a normal and expected part of exercise participation. Regardless of severity, an injury typically results in the athlete's short- or long-term removal from participation. Nutritional interventions may augment the recovery process and support optimal healing; therefore, incorporating nutritional strategies is important at each stage of the healing process. Preoperative nutrition and nutritional demands during rehabilitation are key factors to consider. The physiological response to wounds, immobilization, and traumatic brain injuries may be improved by optimizing macronutrient composition, caloric consumption, and nutrient timing and using select dietary supplements. Previous research supports practical nutrition recommendations to reduce surgical complications, minimize deficits after immobilization, and maximize the chance of safe return to play. These recommendations include identifying the individual's caloric requirements to ensure that energy needs are being met. A higher protein intake, with special attention to evenly distributed consumption throughout the day, will help to minimize loss of muscle and strength during immobilization. Dietary-supplement strategies may be useful when navigating the challenges of appropriate caloric intake and timing and a reduced appetite. The rehabilitation process also requires a strong nutritional plan to enhance recovery from injury. Athletic trainers, physical therapists, and other health care professionals should provide basic nutritional recommendations during rehabilitation, discuss the timing of meals with respect to therapy, and refer the patient to a registered dietitian if warranted. Because nutrition plays an essential role in injury recovery and rehabilitation, nutritional interventions should become a component of standard-of-care practice after injury. In this article, we address best practices for implementing nutritional strategies among patients with athletic injuries.

Creatine Supplementation and Brain Health

There is a robust and compelling body of evidence supporting the ergogenic and therapeutic role of creatine supplementation in muscle. Beyond these well-described effects and mechanisms, there is literature to suggest that creatine may also be beneficial to brain health (e.g., cognitive processing, brain function, and recovery from trauma). This is a growing field of research, and the purpose of this short review is to provide an update on the effects of creatine supplementation on brain health in humans. There is a potential for creatine supplementation to improve cognitive processing, especially in conditions characterized by brain creatine deficits, which could be induced by acute stressors (e.g., exercise, sleep deprivation) or chronic, pathologic conditions (e.g., creatine synthesis enzyme deficiencies, mild traumatic brain injury, aging, Alzheimer’s disease, depression). Despite this, the optimal creatine protocol able to increase brain creatine levels is still to be determined. Similarly, supplementation studies concomitantly assessing brain creatine and cognitive function are needed. Collectively, data available are promising and future research in the area is warranted.

Medical Therapies for Concussion

The medications used in postconcussion syndrome are typically used to help manage or minimize disruptive symptoms while recovery proceeds. These medications are not routinely used in most concussions that recover within days to weeks. However, it is beneficial to be aware of medication options that may be used in athletes with prolonged concussion symptoms or for those that have symptom burdens that preclude entry into basic concussion protocols. Medications and supplements remain a small part of the concussion treatment plan, which may include temporary academic adjustments, physical therapy, vestibular and ocular therapy, psychological support, and graded noncontact exercise.

A Pilot Study Assessing the Impact of rs174537 on Circulating Polyunsaturated Fatty Acids and the Inflammatory Response in Patients with Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability in persons under age 45. The hallmark secondary injury profile after TBI involves dynamic interactions between inflammatory and metabolic pathways including fatty acids. Omega-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) have been shown to provide neuroprotective benefits by minimizing neuroinflammation in rodents. These effects have been less conclusive in humans, however. We postulate genetic variants influencing PUFA metabolism in humans could contribute to these disparate findings. Therefore, we sought to (1) characterize the circulating PUFA response and (2) evaluate the impact of rs174537 on inflammation after TBI. A prospective, single-center, observational pilot study was conducted to collect blood samples from Level-1 trauma patients (N = 130) on admission and 24 h post-admission. Plasma was used to quantify PUFA levels and inflammatory cytokines. Deoxyribonucleic acid was extracted and genotyped at rs174537. Associations between PUFAs and inflammatory cytokines were analyzed for all trauma cases and stratified by race (Caucasians only), TBI (TBI: N = 47; non-TBI = 83) and rs174537 genotype (GG: N = 33, GT/TT: N = 44). Patients with TBI had higher plasma DHA levels compared with non-TBI at 24 h post-injury (p = 0.013). The SNP rs174537 was associated with both PUFA levels and inflammatory cytokines (p < 0.05). Specifically, TBI patients with GG genotype exhibited the highest plasma levels of DHA (1.33%) and interleukin-8 (121.5 ± 43.3 pg/mL), which were in turn associated with poorer outcomes. These data illustrate the impact of rs174537 on the post-TBI response. Further work is needed to ascertain how this genetic variant directly influences inflammation after trauma.

Evaluation of current post-concussion protocols

The growing number of concussions and mild traumatic brain injuries (mTBI) with the lack of evidence-based treatment options is a continuous health concern. This creates problems when evaluating and providing efficacious symptom management to patients suffering from post-concussion syndrome (PCS). Numerous pharmacological and non-pharmacological agents have been utilized in an attempt to treat PCS. Some of these approaches include physical therapy, analgesics, antidepressants, and nutraceuticals. Although these treatments have had some success, there has been inconsistent outcomes, with some examples of patients' symptoms worsening. Among pharmaceutical agents, fluoxetine has been a popular choice for the symptom management of PCS. Although some patients have had symptom resolution with the use of fluoxetine, there is still a lack of conclusive data. Of the several biochemical changes that occur in a patient's brain following a concussion, an increase in reactive oxygen species (ROS) is of particular concern. In order to counteract the responses of the brain, antioxidants, such as ascorbic acid, have been utilized to reverse the damaging cellular effects. However, this may inadvertently cause an increase in ROS, rather than a reduction. Although there is a lack of consistency in exactly when each treatment was used in the post-injury interval, it is important that we analyze the strengths and weaknesses of the most commonly used agents due to the lack of a set protocol. The studies were chosen in a non-exhaustive manner and were not consistent in patients' post-injury intervals, in addition to other baseline characteristics. However, over-arching claims that some treatments may benefit more than others can be made. This review evaluates both the pharmaceutical and non-pharmaceutical protocols that are most commonly utilized in post-concussive patients for their efficacy in treatment of post-concussive syndrome (PCS).

Reduced Reelin Expression in the Hippocampus after Traumatic Brain Injury

Traumatic brain injury (TBI) is a relatively common occurrence following accidents or violence, and often results in long-term cognitive or motor disability. Despite the high health cost associated with this type of injury, presently there are no effective treatments for many neurological symptoms resulting from TBI. This is due in part to our limited understanding of the mechanisms underlying brain dysfunction after injury. In this study, we used the mouse controlled cortical impact (CCI) model to investigate the effects of TBI, and focused on Reelin, an extracellular protein that critically regulates brain development and modulates synaptic activity in the adult brain. We found that Reelin expression decreases in forebrain regions after TBI, and that the number of Reelin-expressing cells decrease specifically in the hippocampus, an area of the brain that plays an important role in learning and memory. We also conducted in vitro experiments using mouse neuronal cultures and discovered that Reelin protects hippocampal neuronal cells from glutamate-induced neurotoxicity, a well-known secondary effect of TBI. Together our findings suggest that the loss of Reelin expression may contribute to neuronal death in the hippocampus after TBI, and raise the possibility that increasing Reelin levels or signaling activity may promote functional recovery.

Lipase Treatment of Dietary Krill Oil, but Not Fish Oil, Enables Enrichment of Brain Eicosapentaenoic Acid and Docosahexaenoic Acid

SCOPE

Currently available omega-3 fatty acid supplements do not enrich the docosahexaenoic acid (DHA) of the adult brain because they are absorbed as triacylglycerol, whereas the transporter at the blood brain barrier requires lysophosphatidylcholine (LPC)-DHA. The hypothesis that treatment of krill oil (KO), which contains DHA/eicosapentaenoic acid (EPA) at the SN2 position of phosphatidylcholine, with SN1-specific lipase will generate LPC-DHA/EPA and which can be absorbed intact and transported into the brain, is tested.

METHODS

KO and fish oil (FO) are treated with Mucor meihei lipase, incorporated into AIN 93G diet, and fed to 2-month-old mice for 30 days. Fatty acid composition is analyzed by gas chromatography/mass spectroscopy. Brain derived neurotrophic factor (BDNF) is measured by ELISA.

RESULTS

Lipase-treated (LT) KO increases brain DHA and EPA, respectively, 5-and 70-fold better than untreated (UT) KO. FO, whether lipase-treated or not, has no effect on brain DHA/EPA. LTKO is also more efficient in enriching liver DHA/EPA, but less efficient than UTKO and FO in enriching adipose tissue and heart. Brain BDNF is significantly increased by LTKO, but only marginally by other preparations.

CONCLUSIONS

Pretreatment of dietary KO with lipase enables it to efficiently increase brain DHA/EPA because of the generation of LPC-DHA/EPA.

Dietary and Biological Assessment of the Omega-3 Status of Collegiate Athletes: A Cross-Sectional Analysis

Omega-3 fatty acids (ω-3 FA) are associated with cardiovascular health, brain function, reduction of inflammation, and several other physiological roles of importance to competitive athletes. The ω-3 FA status of National Collegiate Athletic Association (NCAA) Division I athletes has not been well-described. The purpose of this study was to evaluate the ω-3 FA status of NCAA Division I athletes using dietary and biological assessment methodology. Athletes from nine NCAA Division I institutions from throughout the U.S. (n = 1,528, 51% male, 34 sports represented, 19.9 ± 1.4 years of age) completed a food frequency questionnaire (FFQ) to assess ω-3 FA from diet and supplements. Omega-3 Index (O3i) was evaluated in a sub-set of these participants (n = 298, 55% male, 21 sports represented, 20.0 ± 1.3 years of age) using dried blood spot sampling. Only 6% (n = 93) of athletes achieved the Academy of Nutrition & Dietetics’ recommendation to consume 500 mg DHA+EPA per day. Use of ω-3 FA supplements was reported by 15% (n = 229) of participants. O3i was 4.33 ± 0.81%, with no participants meeting the O3i benchmark of 8% associated with the lowest risk of cardiovascular disease. Every additional weekly serving of fish or seafood was associated with an absolute O3i increase of 0.27%. Overall, sub-optimal ω-3 FA status was observed among a large, geographically diverse group of male and female NCAA Division I athletes. These findings may inform interventions aimed at improving ω-3 FA status of collegiate athletes. Further research on athlete-specific ω-3 FA requirements is needed.

Sports Supplements: Pearls and Pitfalls

Sports supplements can be generally divided into 3 categories: sports foods (foods/drinks containing macronutrients), medical supplements (vitamins/minerals used to treat deficiencies), and ergogenic supplements (used to benefit performance). Supplements are not regulated by the US Food and Drug Administration. They may get to the market and be contaminated with substances banned in sport or dangerous to health; and the contents may not contain what is listed on the label. When choosing to use a supplement, the safest practice is to choose a certified brand, which tests and authenticates label verification, quality, and lack of contaminants and banned substances for sport.

Contribution of Connexin Hemichannels to the Decreases in Cell Viability Induced by Linoleic Acid in the Human Lens Epithelial Cells (HLE-B3)

Connexin (Cx) proteins form gap junction channels (GJC) and hemichannels that a allow bidirectional flow of ions and metabolites between the cytoplasm and extracellular space, respectively. Under physiological conditions, hemichannels have a very low probability of opening, but in certain pathologies, hemichannels activity can increase and induce and/or accelerate cell death. Several mechanisms control hemichannels activity, including phosphorylation and oxidation (i.e., S-nitrosylation). Recently, the effect of polyunsaturated fatty acids (PUFAs) such as linoleic acid (LA), were found to modulate Cxs. It has been seen that LA increase cell death in bovine and human lens cells. The lens is a structure allocated in the eye that highly depends on Cx for the metabolic coupling between its cells, a condition necessary for its transparency. Therefore, we hypothesized that LA induces lens cells death by modulating hemichannel activity. In this work, we characterized the effect of LA on hemichannel activity and survival of HLE-B3 cells (a human lens epithelial cell line). We found that HLE-B3 cells expresses Cx43, Cx46, and Cx50 and can form functional hemichannels in their plasma membrane. The extracellular exposure to 10–50 μM of LA increases hemichannels activity (dye uptake) in a concentration-dependent manner, which was reduced by Cx-channel blockers, such as the Cx-mimetic peptide Gap27 and TATGap19, La³⁺, carbenoxolone (CBX) and the Akt kinase inhibitor. Additionally, LA increases intracellular calcium, which is attenuated in the presence of TATGap19, a specific Cx43-hemichannel inhibitor. Finally, the long exposure of HLE-B3 cells to LA 20 and 50 μM, reduced cell viability, which was prevented by CBX. Moreover, LA increased the proportion of apoptotic HLE-B3 cells, effect that was prevented by the Cx-mimetic peptide TAT-Gap19 but not by Akt inhibitor. Altogether, these findings strongly suggest a contribution of hemichannels opening in the cell death induced by LA in HLE-B3 cells. These cells can be an excellent tool to develop pharmacological studies in vitro.

Reduced Neuroinflammation and Improved Functional Recovery after Traumatic Brain Injury by Prophylactic Diet Supplementation in Mice

Currently, there are no approved therapeutic drugs for the treatment of traumatic brain injury (TBI), and new targets and approaches are needed to provide relief from the long-term effects of TBI. Recent studies suggest that nutrition plays a critical role in improving the outcome from TBI in both civilians and military personnel. We have previously shown that GrandFusion^® (GF) diets improved recovery from cerebral ischemia and enhanced physical activity and endurance in rodent models. We, therefore, sought to determine the impact of a prophylactic diet enriched in fruits and vegetables on recovery from TBI in the controlled cortical impact rodent model. Results demonstrated that mice fed the diets had improved neuromotor function, reduced lesion volume, increased neuronal density in the hippocampus and reduced inflammation. As previously shown, TBI increases cathepsin B as part of the inflammasome complex resulting in elevated inflammatory markers like interleukin-1β (IL-1β). Consumption of the GF diets attenuated the increase in cathepsin B levels and prevented the increase in the proapoptotic factor Bax following TBI. These data suggest that prior consumption of diets enriched in fruits and vegetables either naturally or through powdered form can provide protection from the detrimental effects of TBI.

Sport-Related Concussion in Children and Adolescents

Sport-related concussion is an important topic in nearly all sports and at all levels of sport for children and adolescents. Concussion knowledge and approaches to management have progressed since the American Academy of Pediatrics published its first clinical report on the subject in 2010. Concussion's definition, signs, and symptoms must be understood to diagnose it and rule out more severe intracranial injury. Pediatric health care providers should have a good understanding of diagnostic evaluation and initial management strategies. Effective management can aid recovery and potentially reduce the risk of long-term symptoms and complications. Because concussion symptoms often interfere with school, social life, family relationships, and athletics, a concussion may affect the emotional well-being of the injured athlete. Because every concussion has its own unique spectrum and severity of symptoms, individualized management is appropriate. The reduction, not necessarily elimination, of physical and cognitive activity is the mainstay of treatment. A full return to activity and/or sport is accomplished by using a stepwise program while evaluating for a return of symptoms. An understanding of prolonged symptoms and complications will help the pediatric health care provider know when to refer to a specialist. Additional research is needed in nearly all aspects of concussion in the young athlete. This report provides education on the current state of sport-related concussion knowledge, diagnosis, and management in children and adolescents.

Mild Traumatic Brain Injury in Mice Beneficially Alters Lung NK1R and Structural Protein Expression to Enhance Survival after Pseudomonas aeruginosa Infection

Mild traumatic brain injury (mTBI) in a murine model increases survival to a bacterial pulmonary challenge compared with blunt tail trauma (TT). We hypothesize substance P and its receptor, the neurokinin 1 receptor (NK1R; official name TACR1), play a role in the increased survival of mTBI mice. Mice were subjected to mTBI or TT, and 48 hours after trauma, the levels of NK1R mRNA and protein were significantly up-regulated in mTBI lungs. Examination of the lung 48 hours after injury by microarray showed significant differences in the expression of 433 gene sets between groups, most notably genes related to intercellular proteins. Despite down-regulated gene expression of connective proteins, the presence of an intact pulmonary vasculature was supported by normal histology and bronchoalveolar lavage protein levels. To determine whether these mTBI-induced lung changes benefited in vivo responses, two chemotactic stimuli (a CXCL1 chemokine and a live Pseudomonas aeruginosa infection) were administered 48 hours after trauma. For both stimuli, mTBI mice recruited more neutrophils to the lung 4 hours after instillation (CXCL1: mTBI = 6.3 ± 1.3 versus TT = 3.3 ± 0.7 neutrophils/mL; Pseudomonas aeruginosa: mTBI = 9.4 ± 1.4 versus TT = 5.3 ± 1.1 neutrophils/mL). This study demonstrates that the downstream consequences of mTBI on lung NK1R levels and connective protein expression enhance neutrophil recruitment to a stimulus that may contribute to increased survival.

Neuroinflammation and blood-brain barrier disruption following traumatic brain injury: Pathophysiology and potential therapeutic targets

Traumatic Brain Injury (TBI) is the most frequent cause of death and disability in young adults and children in the developed world, occurring in over 1.7 million persons and resulting in 50,000 deaths in the United States alone. The Centers for Disease Control and Prevention estimate that between 3.2 and 5.3 million persons in the United States live with a TBI-related disability, including several neurocognitive disorders and functional limitations. Following the primary mechanical injury in TBI, literature suggests the presence of a delayed secondary injury involving a variety of neuroinflammatory changes. In the hours to days following a TBI, several signaling molecules and metabolic derangements result in disruption of the blood-brain barrier, leading to an extravasation of immune cells and cerebral edema. The primary, sudden injury in TBI occurs as a direct result of impact and therefore cannot be treated, but the timeline and pathophysiology of the delayed, secondary injury allows for a window of possible therapeutic options. The goal of this review is to discuss the pathophysiology of the primary and delayed injury in TBI as well as present several preclinical studies that identify molecular targets in the potential treatment of TBI. Additionally, certain recent clinical trials are briefly discussed to demonstrate the current state of TBI investigation.

Beyond muscle: the effects of creatine supplementation on brain creatine, cognitive processing, and traumatic brain injury

The ergogenic and therapeutic effects of increasing muscle creatine by supplementation are well-recognized. It appears that similar benefits to brain function and cognitive processing may also be achieved with creatine supplementation, however research in this area is more limited, and important knowledge gaps remain. The purpose of this review is to provide a comprehensive overview of the current state of knowledge about the influence of creatine supplementation on brain function in healthy individuals. It appears that brain creatine is responsive to supplementation, however higher, or more prolonged dosing strategies than those typically used to increase muscle creatine, may be required to elicit an increase in brain creatine. The optimal dosing strategy to induce this response, is currently unknown, and there is an urgent need for studies investigating this. When considering the influence of supplementation strategies on cognitive processes, it appears that creatine is most likely to exert an influence in situations whereby cognitive processes are stressed, e.g. during sleep deprivation, experimental hypoxia, or during the performance of more complex, and thus more cognitively demanding tasks. Evidence exists indicating that increased brain creatine may be effective at reducing the severity of, or enhancing recovery from mild traumatic brain injury, however, only limited data in humans are available to verify this hypothesis, thus representing an exciting area for further research.

IOC consensus statement: dietary supplements and the high-performance athlete

Nutrition usually makes a small but potentially valuable contribution to successful performance in elite athletes, and dietary supplements can make a minor contribution to this nutrition programme. Nonetheless, supplement use is widespread at all levels of sport. Products described as supplements target different issues, including (1) the management of micronutrient deficiencies, (2) supply of convenient forms of energy and macronutrients, and (3) provision of direct benefits to performance or (4) indirect benefits such as supporting intense training regimens. The appropriate use of some supplements can benefit the athlete, but others may harm the athlete's health, performance, and/or livelihood and reputation (if an antidoping rule violation results). A complete nutritional assessment should be undertaken before decisions regarding supplement use are made. Supplements claiming to directly or indirectly enhance performance are typically the largest group of products marketed to athletes, but only a few (including caffeine, creatine, specific buffering agents and nitrate) have good evidence of benefits. However, responses are affected by the scenario of use and may vary widely between individuals because of factors that include genetics, the microbiome and habitual diet. Supplements intended to enhance performance should be thoroughly trialled in training or simulated competition before being used in competition. Inadvertent ingestion of substances prohibited under the antidoping codes that govern elite sport is a known risk of taking some supplements. Protection of the athlete's health and awareness of the potential for harm must be paramount; expert professional opinion and assistance is strongly advised before an athlete embarks on supplement use.

IOC Consensus Statement: Dietary Supplements and the High-Performance Athlete

Nutrition usually makes a small but potentially valuable contribution to successful performance in elite athletes, and dietary supplements can make a minor contribution to this nutrition program. Nonetheless, supplement use is widespread at all levels of sport. Products described as supplements target different issues, including the management of micronutrient deficiencies, supply of convenient forms of energy and macronutrients, and provision of direct benefits to performance or indirect benefits such as supporting intense training regimens. The appropriate use of some supplements can offer benefits to the athlete, but others may be harmful to the athlete's health, performance, and/or livelihood and reputation if an anti-doping rule violation results. A complete nutritional assessment should be undertaken before decisions regarding supplement use are made. Supplements claiming to directly or indirectly enhance performance are typically the largest group of products marketed to athletes, but only a few (including caffeine, creatine, specific buffering agents and nitrate) have good evidence of benefits. However, responses are affected by the scenario of use and may vary widely between individuals because of factors that include genetics, the microbiome, and habitual diet. Supplements intended to enhance performance should be thoroughly trialed in training or simulated competition before implementation in competition. Inadvertent ingestion of substances prohibited under the anti-doping codes that govern elite sport is a known risk of taking some supplements. Protection of the athlete's health and awareness of the potential for harm must be paramount, and expert professional opinion and assistance is strongly advised before embarking on supplement use.

Monitoring changes of docosahexaenoic acid-containing lipids during the recovery process of traumatic brain injury in rat using mass spectrometry imaging

Brain lipid homoeostasis is critical during recovery process after traumatic brain injury (TBI). In this study, we integrated liquid extraction and electrosonic spray ionization technology to develop an ionization device coupled with a Fourier transform ion cyclotron resonance mass spectrometer for imaging of docosahexaenoic acid (DHA)-containing lipids on rat brain tissues. The ion images of the brain tissue sections from the normal rats and the rats after TBI at acute phase (0 and 1 day) and chronic phase (3, 5, and 7 days) were obtained. The imaging results indicate that the levels of DHA and lyso-phosphatidylethanolamine (22:6) in the injury area of TBI rats increased significantly at the acute phase and subsequently decreased at the chronic phase. But the levels of DHA-containing phospholipids including phosphatidylethanolamine (PE)(P-18:0/22:6), PE(18:0/22:6), and phosphatidylserine (18:0/22:6) decreased at the acute phase and gradually increased at the chronic phase in the injury area accompanied by the morphogenesis and wound healing. These findings indicate that the DHA may participate in the recovery process of brain injury. This is the first report to in situ detect the changes in the levels of DHA and DHA-containing lipids in the TBI model.

Erythrocyte Omega-3 Fatty Acid Content in Elite Athletes in Response to Omega-3 Supplementation: A Dose-Response Pilot Study

Introduction

Supplementation of Omega-3 fatty acids (n-3FA) in athletes is related to the anti-inflammatory and/or antioxidant effect and consequently its action on all the processes of tissue restoration and adaptation to physical stress.

Objective

Evaluate the Omega-3 Index (O3Ix) response, in red blood cells, to supplemental EPA + DHA intake in the form of high purity and stable composition gums (G), in elite summer athletes.

Method

Twenty-four summer sport athletes of both sexes, pertaining to the Olympic Training Center in Spain, were randomized to two groups (2G = 760 or 3G = 1140 mg of n-3 FA in Omegafort OKids, Ferrer Intl.) for 4 months. Five athletes and four training staff volunteers were control group.

Results

The O3Ix was lower than 8% in 93.1% of all the athletes. The supplementation worked in a dose-dependent manner: 144% for the 3G dose and 135% for the 2G, both p < 0.001, with a 3% significant decrease of Omega-6 FAs. No changes were observed for the control group.

Conclusions

Supplementation with n-3FA increases the content of EPA DHA in the red blood cells at 4 months in a dose-dependent manner. Athletes with lower basal O3Ix were more prone to increment their levels. The study is registered with Protocol Registration and Results System (ClinicalTrials.gov) number NCT02610270.

Nutrition practices and knowledge among NCAA Division III football players

Background

Participation in collegiate American football is physically demanding and may have long-term health implications, particularly in relation to cardiovascular and neurological health. National Collegiate Athletic Association (NCAA) Division III (DIII) football players are a relatively unstudied population, particularly in terms of their dietary habits and knowledge. The aim of the present study was to descriptively evaluate the dietary intake of DIII football players including a subset of linemen and assess the nutritional knowledge and sources of information of these athletes.

Methods

The study sample was 88 DIII football players including a subset of nine linemen. All participants completed a food frequency questionnaire, and a nutritional knowledge questionnaire that included a quiz and questions about their main sources of nutrition information. Heights and body masses were also recorded. The linemen submitted written 3-day diet records for assessment of their dietary intake.

Results

Of the 88 participants, >50% reported consuming starches/grains, meat and dairy daily, but <50% reported consuming fruits and vegetables daily. Protein powders were the most commonly used supplements (33% reported daily use). Compared to dietary recommendations, linemen consumed high amounts of total fat, saturated fat, dietary cholesterol, sodium, and potassium, but were low in carbohydrates, fiber, and essential fats. The mean nutrition knowledge quiz score for the 88 participants was 55.2%. Those who had taken a nutrition or health course in college scored significantly higher on the quiz than those who had not. Participants reported relying primarily on coaches, websites, and athletic trainers (ATs) for nutritional guidance; ATs were the most trusted source.

Conclusions

DIII football players had dietary habits that may both mitigate and increase their risk of chronic diseases. These athletes have room to improve their nutrition knowledge. Their reliance on athletic team staff for nutrition guidance highlights the importance of nutrition education for both athletes and staff and the potential role of a registered dietitian nutritionist.

Electronic supplementary material

The online version of this article (doi:10.1186/s12970-017-0170-2) contains supplementary material, which is available to authorized users.

Fatty acid requirements for the preterm infant

Fatty acids are critical nutrient regulators of intracellular signaling and influence key pathways including inflammatory responses, hemostasis as well as central nervous system development and function. Preterm birth interrupts the maternal-fetal transfer of essential fatty acids including docosahexaenoic and arachidonic acids, which occurs during the third trimester. Postnatal deficits of these nutrients accrue in preterm infants during the first week and they remain throughout the first months. Due to the regulatory roles of these fatty acids, such deficits contribute an increased risk of developing prematurity-related morbidities including impaired growth and neurodevelopment. The fatty acid contents of parenteral and enteral nutrition are insufficient to meet current recommendations. This chapter summarizes the regulatory roles of fatty acids, current recommendations and limitations of parenteral and enteral nutrition in meeting these recommendations in preterm infants. Suggested areas for research on the roles of fatty acids in preterm infant health are also provided.

Nutritional Support for Exercise-Induced Injuries

Nutrition is one method to counter the negative impact of an exercise-induced injury. Deficiencies of energy, protein and other nutrients should be avoided. Claims for the effectiveness of many other nutrients following injuries are rampant, but the evidence is equivocal. The results of an exercise-induced injury may vary widely depending on the nature of the injury and severity. Injuries typically result in cessation, or at least a reduction, in participation in sport and decreased physical activity. Limb immobility may be necessary with some injuries, contributing to reduced activity and training. Following an injury, an inflammatory response is initiated and while excess inflammation may be harmful, given the importance of the inflammatory process for wound healing, attempting to drastically reduce inflammation may not be ideal for optimal recovery. Injuries severe enough for immobilization of a limb result in loss of muscle mass and reduced muscle strength and function. Loss of muscle results from reductions in basal muscle protein synthesis and the resistance of muscle to anabolic stimulation. Energy balance is critical. Higher protein intakes (2-2.5 g/kg/day) seem to be warranted during immobilization. At the very least, care should be taken not to reduce the absolute amount of protein intake when energy intake is reduced. There is promising, albeit preliminary, evidence for the use of omega-3 fatty acids and creatine to counter muscle loss and enhance hypertrophy, respectively. The overriding nutritional recommendation for injured exercisers should be to consume a well-balanced diet based on whole, minimally processed foods or ingredients made from whole foods. The diet composition should be carefully assessed and changes considered as the injury heals and activity patterns change.

Effect of dietary docosahexaenoic acid (DHA) in phospholipids or triglycerides on brain DHA uptake and accretion

Tracer studies suggest that phospholipid DHA (PL-DHA) more effectively targets the brain than triglyceride DHA (TAG-DHA), although the mechanism and whether this translates into higher brain DHA concentrations are not clear. Rats were gavaged with [U-(3)H]PL-DHA and [U-(3)H]TAG-DHA and blood sampled over 6h prior to collection of brain regions and other tissues. In another experiment, rats were supplemented for 4weeks with TAG-DHA (fish oil), PL-DHA (roe PL) or a mixture of both for comparison to a low-omega-3 diet. Brain regions and other tissues were collected, and blood was sampled weekly. DHA accretion rates were estimated using the balance method. [U-(3)H]PL-DHA rats had higher radioactivity in cerebellum, hippocampus and remainder of brain, with no differences in other tissues despite higher serum lipid radioactivity in [U-(3)H]TAG-DHA rats. TAG-DHA, PL-DHA or a mixture were equally effective at increasing brain DHA. There were no differences between DHA-supplemented groups in brain region, whole-body, or tissue DHA accretion rates except heart and serum TAG where the PL-DHA/TAG-DHA blend was higher than TAG-DHA. Apparent DHA β-oxidation was not different between DHA-supplemented groups. This indicates that more labeled DHA enters the brain when consumed as PL; however, this may not translate into higher brain DHA concentrations.

Plasma non-esterified docosahexaenoic acid is the major pool supplying the brain

Despite being critical for normal brain function, the pools that supply docosahexaenoic acid (DHA) to the brain are not agreed upon. Using multiple kinetic models in free-living adult rats, we first demonstrate that DHA uptake from the plasma non-esterified fatty acid (NEFA) pool predicts brain uptake of DHA upon oral administration, which enters the plasma NEFA pool as well as multiple plasma esterified pools. The rate of DHA loss by the brain is similar to the uptake from the plasma NEFA pool. Furthermore, upon acute iv administration, although more radiolabeled lysophosphatidylcholine (LPC)-DHA enters the brain than NEFA-DHA, this is due to the longer plasma half-life and exposure to the brain. Direct comparison of the uptake rate of LPC-DHA and NEFA-DHA demonstrates that uptake of NEFA-DHA into the brain is 10-fold greater than LPC-DHA. In conclusion, plasma NEFA-DHA is the major plasma pool supplying the brain.