Abstract: Repeated head trauma sustained in early life through collision sports like football have prompted increased efforts from the public health and scientific communities to understand the long-term implications of adolescent participation in collision sports on later life cognitive health. To date, literature has focused on professional athletes and/or concussions whereas fewer studies have examined how adolescent participation in collision sports may shape trajectories of cognitive health in later life. We examined the association between early-life participation in collision sports and later life cognitive health among a sample of Swedish twins aged 50 years. Cognitive measures included the Mini-Mental State Examination and performance across multiple cognitive domains (e.g., global cognition, verbal ability, spatial ability, memory, processing speed). Among a sample of 660 adults who contributed 9,431 person-years of follow-up, there were 450 cases of dementia (crude rate: 47.7/1,000 person-years). Early-life participation in collision sports was not significantly associated with dementia at baseline nor its onset over a 28-year period. Furthermore, early-life participation in collision sports was not significantly associated with the level of or change in trajectories of cognition across multiple domains. We discuss the long-term implications of adolescent participation in collision sports on cognitive health. —
A pre-analysis protocol for this work is available at arXiv:1807.10558.