Epidemiology of neurodegeneration in American-style professional football players

Abstract

The purpose of this article is to review the history of head injuries in relation to American-style football play, summarize recent research that has linked football head injuries to neurodegeneration, and provide a discussion of the next steps for refining the examination of neurodegeneration in football players. For most of the history of football, the focus of media reports and scientific studies on football-related head injuries was on the acute or short-term effects of serious, traumatic head injuries. Beginning about 10 years ago, a growing concern developed among neurologists and researchers about the long-term effects that playing professional football has on the neurologic health of the players. Autopsy-based studies identified a pathologically distinct neurodegenerative disorder, chronic traumatic encephalopathy, among athletes who were known to have experienced concussive and subconcussive blows to the head during their playing careers. Football players have been well represented in these autopsy findings. A mortality study of a large cohort of retired professional football players found a significantly increased risk of death from neurodegeneration. Further analysis found that non-line players were at higher risk than line players, possibly because of an increased risk of concussion. Although the results of the studies reviewed do not establish a cause effect relationship between football-related head injury and neurodegenerative disorders, a growing body of research supports the hypothesis that professional football players are at an increased risk of neurodegeneration. Significant progress has been made in the last few years on detecting and defining the pathology of neurodegenerative diseases. However, less progress has been made on other factors related to the progression of those diseases in football players. This review identifies three areas for further research: (a) quantification of exposure - a consensus is needed on the use of clinically practical measurements of blows to the head among football players; (b) genetic susceptibility factors - a more rigorous set of unbiased epidemiological and clinical studies is needed before any causal relationships can be drawn between suspected genetic factors, head injury, and neurodegeneration; and (c) earlier detection and prevention of neurodegenerative diseases.

Clinical Features of Repetitive Traumatic Brain Injury and Chronic Traumatic Encephalopathy

“…It is not yet clear whether the pathology in these cases represents a variant of CTE or CTE with overlapping comorbid disease. Recent data suggest that professional American football players have more than four times the risk of dying from amyotrophic lateral sclerosis (ALS) MND than age-and gender-matched controls (47). Our recent review of the world's literature (61) uncovered the first case of CTE MND ever reported (57) with pathological evidence to support the link between sport-related RTBI and atypical ALS.…”

Hypolipidaemic and antioxidant capacities of polysaccharides obtained from Laminaria japonica by different extraction media in diet‐induced mouse model

“…Diet and lifestyle are major factors that influence the susceptibility to diseases especially heart disease, stroke, obesity and type II diabetes (Lehman, 2013;Parish, 2013). A fast-moving lifestyle and continuous exposure to environmental pollution along with an unhealthy diet lead to increased psychological and physical stress causing excessive reactive oxygen species (ROS) and reactive nitrogen species (RNS) that overwhelm the natural antioxidant defence system of the human body.…”

Alzheimer’s disease and chronic traumatic encephalopathy: Distinct but possibly overlapping disease entities

“…40 As has been previously reported, professional football players have a 3-fold increase in neurodegenerative mortality, and are at the highest risk for developing modern CTE (excluding boxers diagnosed with dementia pugilistica ). 41,42 In addition, upwards of a quarter of military service personnel are exposed to blast waves during training and active duty. 43 The duration of repetitive exposure to head injury is closely correlated to injury severity.…”