Effects of current exercise and diet on late-life cognitive health of former college football players

Effect of a plant-based diet on oxidative stress biomarkers in male footballers

Proper nutrition plays a vital role in modulating oxidative status. There is an increasing popularity of plant-based dietary patterns among athletes. Therefore, the present study aimed to determine the plant-based diet index (PDI) score among male footballers and their non-athlete controls, as well as its relationship with oxidative biomarkers by evaluating the urinary excretion of F2alpha-isoprostane (F2a-IP) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). A group of footballers (n = 45) and a healthy non-athlete group (n = 45) were selected. The two groups were matched based on body mass index (BMI) and age. The mean (standard deviation (SD)) age of the subjects was 22.88 (2.41) years, and their BMI was 22.08 (1.35) kg/m2. Anthropometric indices were evaluated, and fasting morning urine samples were analyzed to measure oxidative biomarkers. The PDI, unhealthy plant-based diet index (uPDI), and healthy plant-based diet index (hPDI) were calculated using valid food frequency questionnaire data. Generalized estimating equation models were used for all analyses. Compared to the non-athlete group, the PDI score was significantly greater in the footballer group (β = 9.8; P < 0.001), while the differences between the two groups in uPDI and hPDI scores were not significant. Overall, footballers consumed more plant-based foods. By examining the relationship between dietary indices and oxidative biomarkers, only a negative association was observed between PDI score and F2a-IP level (β = -1.25; P = 0.03). Based on the results, footballers were more adherent to a plant-based diet than non-athletes. In addition, it seems that following plant-based diets (the higher PDI) may exert beneficial effects on lowering F2a-IP levels due to improving the body's antioxidant status.

Microtemporal Dynamics of Dietary Intake, Physical Activity, and Impulsivity in Adult Attention-Deficit/Hyperactivity Disorder: Ecological Momentary Assessment Study Within Nutritional Psychiatry

BACKGROUND

Increasing attention is being paid to lifestyle factors, such as nutrition and physical activity (PA), as potential complementary treatment options in attention-deficit/hyperactivity disorder (ADHD). Previous research indicates that sugar and saturated fat intake may be linked to increased impulsivity, a core symptom of ADHD, whereas protein intake and PA may be related to reduced impulsivity. However, most studies rely on cross-sectional data that lack microtemporal resolution and ecological validity, wherefore questions of microtemporal dynamics (eg, is the consumption of foods high in sugar associated with increased impulsivity within minutes or hours?) remain largely unanswered. Ecological momentary assessment (EMA) has the potential to bridge this gap.

OBJECTIVE

This study is the first to apply EMA to assess microtemporal associations among macronutrient intake, PA, and state impulsivity in the daily life of adults with and without ADHD.

METHODS

Over a 3-day period, participants reported state impulsivity 8 times per day (signal-contingent), recorded food and drink intake (event-contingent), and wore an accelerometer. Multilevel 2-part models were used to study the association among macronutrient intake, PA, and the probability to be impulsive as well as the intensity of impulsivity (ADHD: n=36; control: n=137).

RESULTS

No association between macronutrient intake and state impulsivity was found. PA was not related to the intensity of impulsivity but to a higher probability to be impulsive (ADHD: β=-.09, 95% CI -0.14 to -0.04; control: β=-.03, 95% CI -0.05 to -0.01). No evidence was found that the combined intake of saturated fat and sugar amplified the increase in state impulsivity and that PA alleviated the positive association between sugar or fat intake and state impulsivity.

CONCLUSIONS

Important methodological considerations are discussed that can contribute to the optimization of future EMA protocols. EMA research in the emerging field of nutritional psychiatry is still in its infancy; however, EMA is a highly promising and innovative approach as it offers insights into the microtemporal dynamics of psychiatric symptomology, dietary intake, and PA in daily life.

Association of Playing College American Football With Long-term Health Outcomes and Mortality

IMPORTANCE

Exposure to repetitive head impacts from playing American football (including impacts resulting in symptomatic concussions and subconcussive trauma) is associated with increased risk for later-life health problems, including cognitive and neuropsychiatric decline and neurodegenerative disease. Most research on long-term health consequences of playing football has focused on former professional athletes, with limited studies of former college players.

OBJECTIVES

To estimate the prevalence of self-reported health conditions among former college football players compared with a sample of men in the general population as well as standardized mortality ratios (SMRs) among former college football players.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included data from 447 former University of Notre Dame (ND) football players aged 59 to 75 years who were seniors on the rosters from 1964 to 1980. A health outcomes survey was distributed to living players and next of kin of deceased players for whom contact information was available. The survey was completed from December 2018 to May 2019.

EXPOSURE

Participation in football at ND.

MAIN OUTCOMES AND MEASURES

Prevalence of health outcomes was compared between living former players who completed the survey and propensity score-matched participants in the Health and Retirement Study (HRS). Standardized mortality ratios of all causes and specific causes of death among all former players were compared with those among men in the general US population.

RESULTS

A total of 216 living players completed the health survey (median age, 67 years; IQR, 63-70 years) and were compared with 638 participants in the HRS (median age, 66 years; IQR, 63-70 years). Former players reported a higher prevalence of cognitive impairment (10 [5%] vs 8 [1%]; P = .02), headaches (22 [10%] vs 22 [4%]; P = .001), cardiovascular disease (70 [33%] vs 128 [20%]; P = .001), hypercholesterolemia (111 [52%] vs 182 [29%]; P = .001), and alcohol use (185 [86%] vs 489 [77%]; P = .02) and a lower prevalence of diabetes (24 [11%] vs 146 [23%]; P = .001). All-cause mortality (SMR, 0.54; 95% CI, 0.42-0.67) and mortality from heart (SMR, 0.64; 95% CI, 0.39-0.99), circulatory (SMR, 0.23; 95% CI, 0.03-0.83), respiratory (SMR, 0.13; 95% CI, 0.00-0.70), and digestive system (SMR, 0.13; 95% CI, 0.00-0.74) disorders; lung cancer (SMR, 0.26; 95% CI, 0.05-0.77); and violence (SMR, 0.10; 95% CI, 0.00-0.58) were significantly lower in the ND cohort than in the general population. Mortality from brain and other nervous system cancers was significantly higher in the ND cohort (SMR, 3.82; 95% CI, 1.04-9.77). Whereas point estimates were greater for all neurodegenerative causes (SMR, 1.42; 95% CI, 0.29-4.18), amyotrophic lateral sclerosis (SMR, 2.93; 95% CI, 0.36-10.59), and Parkinson disease (SMR, 2.07; 95% CI, 0.05-11.55), the difference did not reach statistical significance.

CONCLUSIONS AND RELEVANCE

In this cohort study of former college football players, both positive and negative health outcomes were observed. With more than 800 000 former college players living in the US, additional research appears to be needed to provide stakeholders with guidance to maximize factors that improve health outcomes and minimize factors that may increase risk for later-life morbidity and mortality.

Subjective Concerns Regarding the Effects of Sport-Related Concussion on Long-Term Brain Health among Former NFL Players: An NFL-LONG Study

BACKGROUND

Potential links between a history of sport-related concussions and later-life neurobiological and psychological brain health have been studied in former collision-sport athletes. However, empirical studies of how former athletes perceive the future of their brain health as a result of these injuries are missing.

OBJECTIVES

We aimed to (1) identify the extent to which former National Football League players currently have concerns about their long-term psychological and cognitive functioning as a result of concussions sustained while playing football; (2) examine whether current concerns are different than concerns they had while playing football; (3) examine the relationship between current brain health concerns and self-reported concussion history (SR-CHx); and (4) explore other important factors associated with these concerns.

METHODS

In this cross-sectional study, former National Football League players with a SR-CHx of one or more concussions (n = 1514; aged mean [standard deviation] = 52.3 [15.7] years) completed a general health questionnaire. Participants reported their lifetime concussion history, as well as both their current concerns and concerns while playing football (i.e., retrospective concerns) regarding the long-term effects of concussions on their memory, thinking skills, and risk of developing chronic traumatic encephalopathy. Current and retrospective concerns were self-reported on a five-point Likert scale. Four concussion history categories were created based on SR-CHx: 1-2 (n = 309); 3-5 (n = 413); 6-9 (n = 356); and 10 + (n = 436) lifetime concussions. Proportions of participants reporting each level of current and retrospective concerns were examined to identify whether concerns presently exist in these former players, and whether their current concerns are different than retrospective concerns. Next, we explored associations between current concerns and SR-CHx.

RESULTS

More than one-third of participants reported being currently "extremely concerned" about memory problems (36.9%), thinking skills (37.8%), and developing chronic traumatic encephalopathy (39.5%). In contrast, when asked about concerns while playing, most reported being "not at all concerned" regarding memory = 61.2%, thinking skills = 56.1%, and developing chronic traumatic encephalopathy = 71.2%. Of those who retrospectively endorsed being "not at all" or "slightly" concerned regarding memory (n = 1159/1514), thinking skills (n = 1080/1514), and developing chronic traumatic encephalopathy (n = 1219/1514), approximately half reported being currently "moderately" or "extremely" concerned about those same issues (n = 586/1159; n = 534/1080; n = 619/1219, respectively). Current concerns regarding memory (χ²₁₆ = 316.61; p < 0.001; V = 0.264), thinking skills (χ²₁₆ = 333.17; p < 0.001; V = 0.271), and developing chronic traumatic encephalopathy (χ²₁₆ = 280.85; p < 0.001; V = 0.249) were significantly related to SR-CHx, with more concussions being associated with greater current concerns.

CONCLUSIONS

Former National Football League players reported significant concerns regarding the potential effects of their prior concussions on long-term brain health, and these concerns are more prevalent now than when they were playing football. Cognitive and mental health concerns are readily identifiable targets for clinical intervention. Clinicians working with former players may wish to explore the extent to which individual players experience these concerns, the nature and depth of these concerns, and the impact of these concerns on the player's functioning and well-being.

The impact of dietary macronutrient intake on cognitive function and the brain

Macronutrients - carbohydrates, fats, and proteins - supply the nutrients required for optimal functioning. Inadequate intake compromises both physical and brain health. We synthesized research on macronutrients from whole meals on cognitive function in healthy adults and identified underlying mechanisms. Intake of simple carbohydrates ('sugars') is consistently associated with decreased global cognition whereas consumption of complex carbohydrates correlates with successful brain aging and improved memory both in the short- and long-term. Saturated fatty acid intake correlates with decreased memory and learning scores whereas omega-3 intake correlates positively with memory scores. Protein intake boosts executive function and working memory when task-demands are high. Individual differences affecting the macronutrient-cognition relationship are age, physical activity, and glucose metabolism. Neural correlates reflect findings on cognitive functions: cortical thickness and cerebral amyloid burden correlate with sugar intake, inflammatory status and cerebral glucose metabolism correlate with fatty acid intake. Key mechanisms by which dietary macronutrients affect the brain and cognition include glucose and insulin metabolism, neurotransmitter actions, and cerebral oxidation and inflammation. In conclusion, macronutrient intake affects cognitive function both acutely and in the long-term, involving peripheral and central mechanisms. A healthy diet supports brain integrity and functionality, whereas inadequate nutrition compromises it. Studying diet can be key to nutritional recommendations, thereby improving the landscape of mental health and healthy brain aging.

Individual and cumulative health afflictions are associated with greater impairment in physical and mental function in former professional American style football players

BACKGROUND

Former American style football players (ASF players) have recognized health concerns associated with prior sport participation. It remains unknown whether categorizations of current health conditions, referred to in this report as afflictions (conceptually framed as neurocognitive, cardiovascular, cardiometabolic, sleep apnea, and chronic pain) are associated with physical and mental function.

OBJECTIVE

To evaluate the association of afflictions to physical and mental function. It was hypothesized that former National Football League players with any affliction would have worse function compared to unafflicted participants. It was anticipated that multiple afflictions would result in cumulative loss of function.

DESIGN

Cross-sectional retrospective design.

SETTING

Academic medical multisite hospital system.

PARTICIPANTS

A total of 3913 of 15,611 former ASF players who played professionally from 1960 to 2019 (response rate 25%). Assessment of Risk Factors Self-report survey.

MAIN OUTCOME MEASURES

Each participant completed the Patient Reported Outcomes Measurement Information System (PROMIS) Global Health Scale and Physical Function questionnaires. Responses were used to generate two physical function and one mental function subscale scores. Raw scores were converted to T-scores categorized as impaired (T-score < 40) or unimpaired (T-score ≥ 40). Primary analyses measured the association of affliction to function (impaired or unimpaired).

RESULTS

After adjusting for confounders (age, race, position, number of seasons, age of first exposure to football, alcohol use, smoking history, and current body mass index), each affliction was associated with reduced physical function on the Global physical function subscale (risk ratio [RR] = 1.23-2.45, all P < .005), physical function scale (RR = 1.24-2.75, all P < .01), and mental function scale (RR = 1.34-2.87, all P < .001), except that cardiovascular affliction was not associated with mental function (RR = 1.15, P = .15). The lowest functional measures were observed in those afflicted by chronic pain. Cumulative afflictions were associated with worse function.

CONCLUSIONS

Afflictions are associated with cumulative reduction of function. Research evaluating how afflictions interact may help elucidate mechanisms for illness and develop interventions to optimize function.

Health-promoting behaviours and concussion history are associated with cognitive function, mood-related symptoms and emotional-behavioural dyscontrol in former NFL players: an NFL-LONG Study

OBJECTIVES

To examine the relationships among self-reported sport-related concussion (SRC) history and current health-promoting behaviours (exercise frequency, diet quality and sleep duration) with self-reported measures of brain health (cognitive function, symptoms of depression and anxiety and emotional-behavioural dyscontrol) in former NFL players.

METHODS

In this cross-sectional study, a questionnaire was sent to former NFL players. Respondents reported SRC history (categorical: 0; 1-2; 3-5; 6-9; 10+ concussions), number of moderate-to-vigorous aerobic and resistance exercise sessions per week, diet quality (Rapid Eating Assessment for Participants-Shortened) and average nightly sleep duration. Outcomes were Patient-Reported Outcomes Measurement Information System Cognitive Function, Depression, and Anxiety, and Neuro-QoL Emotional-Behavioral Dyscontrol domain T-scores. Multivariable linear regression models were fit for each outcome with SRC history, exercise frequency, diet quality and sleep duration as explanatory variables alongside select covariates.

RESULTS

Multivariable regression models (n=1784) explained approximately 33%-38% of the variance in each outcome. For all outcomes, SRC history (0.144≤|β|≤0.217) was associated with poorer functioning, while exercise frequency (0.064≤|β|≤0.088) and diet quality (0.057≤|β|≤0.086) were associated with better functioning. Sleeping under 6 hours per night (0.061≤|β|≤0.093) was associated with worse depressive symptoms, anxiety and emotional-behavioural dyscontrol.

CONCLUSION

Several variables appear to be associated with mood and perceived cognitive function in former NFL players. SRC history is non-modifiable in former athletes; however, the effects of increasing postplaying career exercise frequency, making dietary improvements, and obtaining adequate sleep represent important potential opportunities for preventative and therapeutic interventions.

History of Sport-Related Concussion and Long-Term Clinical Cognitive Health Outcomes in Retired Athletes: A Systematic Review

BACKGROUND

Sport-related concussions (SRCs) are known to have short-term effects on cognitive processes, which can result in diverse clinical presentations. The long-term effects of SRC and repeated exposure to head impacts that do not result in SRC on specific cognitive health outcomes remain unclear.

OBJECTIVES

To synthesize and appraise the evidence base regarding cognitive health in living retired athletes with a history of head-impact exposure or SRC.

DATA SOURCES

A systematic search of the EMBASE, PsycINFO, MEDLINE/PubMed, CINAHL, Cochrane Central Register of Controlled Trials, and Web of Science databases was conducted from inception to April 2018 using common key words and medical subject headings related to 3 components: (1) the participant (eg, retired athlete), (2) the primary outcome measure (eg, cognitive test used), and (3) the secondary outcome measure (eg, history of sport concussion).

STUDY SELECTION

Cross-sectional studies of living retired male or female athletes in which at least 1 cognitive test was used as an outcome measure were included. Two reviewers independently screened studies.

DATA EXTRACTION

Data extraction was performed using Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Methodologic quality was assessed independently by 2 reviewers using the Downs and Black tool.

DATA SYNTHESIS

The search yielded 46 cross-sectional observational studies that were included in a qualitative synthesis. Most included studies (80%, n = 37) were published in the 5 years before our review. A large proportion of these studies (n = 20) included retired American National Football League players. The other research investigated professional, university, high school, and amateur retired athletes participating in sports such as American and Australian football, boxing, field and ice hockey, rugby, and soccer. The total sample consisted of 13 975 participants: 7387 collision-sport athletes, 662 contact-sport athletes, 3346 noncontact-sport athletes, and 2580 participants classified as controls. Compared with control participants or normative data, retired athletes displayed worse performance in 17 of 31 studies (55%) of memory, 6 of 11 studies (55%) of executive function, and 4 of 6 studies (67%) of psychomotor function and increased subjective concerns about cognitive function in 11 of 14 studies (79%). The authors of 13 of 46 investigations (28%) reported a frequency-response relationship, with poorer cognitive outcomes in athletes who had greater levels of exposure to head impacts or concussions. However, these results must be interpreted in light of the lack of methodologic rigor and moderate quality assessment of the included studies.

CONCLUSIONS

Evidence of poorer cognitive health among retired athletes with a history of concussion and head-impact exposure is evolving. Our results suggest that a history of SRC may more greatly affect the cognitive domains of memory, executive function, and psychomotor function. Retired athletes appeared to have increased self-reported cognitive difficulties, but the paucity of high-quality, prospective studies limited the conclusions that could be drawn regarding a cause-and-effect relationship between concussion and long-term health outcomes. Future researchers should consider a range of cognitive health outcomes, as well as premorbid ability, in diverse samples of athletes with or without a history of concussion or head-impact exposure to delineate the long-term effects of sport participation on cognitive functioning.

Long-Term Cognitive Performance of Retired Athletes with Sport-Related Concussion: A Systematic Review and Meta-Analysis

Objective: The purpose of this systematic review is to quantitatively estimate (or invest) the impacts of sports-related concussions (SRCs) on cognitive performance among retired athletes more than 10 years after retirement. Methods: Six databases including (MEDLINE, Scopus, Web of Science, SPORTDiscus, CINAHL, and PsycArtilces) were employed to retrieve the related studies. Studies that evaluate the association between cognitive function and the SRC of retired athletes sustaining more than 10 years were included. Results: A total of 11 studies that included 792 participants (534 retired athletes with SRC) were identified. The results indicated that the retired athletes with SRCs, compared to the non-concussion group, had significant cognitive deficits in verbal memory (SMD = -0.29, 95% CI -0.59 to -0.02, I² = 52.8%), delayed recall (SMD = -0.30, 95% CI -0.46 to 0.07, I² = 27.9%), and attention (SMD = -0.33, 95% CI -0.59 to -0.06, I² = 0%). Additionally, meta-regression demonstrated that the period of time between testing and the last concussion is significantly associated with reduced verbal memory (β = -0.03681, p = 0.03), and increasing age is significantly associated with the verbal memory (β = -0.03767, p = 0.01), immediate recall (β = -0.08684, p = 0.02), and delay recall (β = -0.07432, p = 0.02). Conclusion: The retired athletes who suffered from SRCs during their playing career had declined cognitive performance in partial domains (immediate recall, visuospatial ability, and reaction time) later in life.

A systematic review of potential long-term effects of sport-related concussion

Objective

Systematic review of possible long-term effects of sports-related concussion in retired athletes.

Data sources

Ten electronic databases.

Study selection

Original research; incidence, risk factors or causation related to long-term mental health or neurological problems; individuals who have suffered a concussion; retired athletes as the subjects and possible long-term sequelae defined as >10 years after the injury.

Data extraction

Study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, neuroimaging findings and neuropathology results. Risk of bias and level of evidence were evaluated by two authors.

Results

Following review of 3819 studies, 47 met inclusion criteria. Some former athletes have depression and cognitive deficits later in life, and there is an association between these deficits and multiple prior concussions. Former athletes are not at increased risk for death by suicide (two studies). Former high school American football players do not appear to be at increased risk for later life neurodegenerative diseases (two studies). Some retired professional American football players may be at increased risk for diminishment in cognitive functioning or mild cognitive impairment (several studies), and neurodegenerative diseases (one study). Neuroimaging studies show modest evidence of macrostructural, microstructural, functional and neurochemical changes in some athletes.

Conclusion

Multiple concussions appear to be a risk factor for cognitive impairment and mental health problems in some individuals. More research is needed to better understand the prevalence of chronic traumatic encephalopathy and other neurological conditions and diseases, and the extent to which they are related to concussions and/or repetitive neurotrauma sustained in sports.

Division III Collision Sports Are Not Associated with Neurobehavioral Quality of Life

We sought to determine whether the exposure to the sub-concussive blows that occur during division III collegiate collision sports affect later life neurobehavioral quality-of-life measures. We conducted a cross-sectional study of alumni from four division III colleges, targeting those between the ages of 40-70 years, using several well-validated quality-of-life measures for executive function, general concerns, anxiety, depression, emotional and behavior dyscontrol, fatigue, positive affect, sleep disturbance, and negative consequences of alcohol use. We used multivariable linear regression to assess for associations between collision sport participation and quality-of-life measures while adjusting for covariates including age, gender, race, annual income, highest educational degree, college grades, exercise frequency, and common medical conditions. We obtained data from 3702 alumni, more than half of whom (2132) had participated in collegiate sports, 23% in collision sports, 23% in non-contact sports. Respondents with a history of concussion had worse self-reported health on several measures. When subjects with a history of concussion were removed from the analyses in order to assess for any potential effect of sub-concussive blows alone, negative consequences of alcohol use remained higher among collision sport athletes (β-coefficient 1.957, 95% CI 0.827-3.086). There were, however, no other significant associations between exposure to collision sports during college and any other quality-of-life measures. Our results suggest that, in the absence of a history of concussions, participation in collision sports at the Division III collegiate level is not a risk factor for worse long-term neurobehavioral outcomes, despite exposure to repeated sub-concussive blows.

Head trauma in sport and neurodegenerative disease: an issue whose time has come?

A number of small studies and anecdotal reports have been suggested that sports involving repeated head trauma may have long-term risks of neurodegenerative disease. There are now plausible mechanisms for these effects, and a recognition that these problems do not just occur in former boxers, but in a variety of sports involving repeated concussions, and possibly also in sports in which low-level head trauma is common. These neurodegenerative effects potentially include increased risks of impaired cognitive function and dementia, Parkinson's disease, and amyotrophic lateral sclerosis. Many would argue for taking a precautionary approach and immediately banning or restricting sports such as boxing. However, there are important public health issues in terms of how wide the net should be cast in terms of other sports, and what remedial measures could be taken? This in turn requires a major research effort involving both clinical and basic research to understand the underlying mechanisms, leading from head trauma to neurodegenerative disease and epidemiologic studies to assess the long-term consequences.