Neurodegenerative Disease and Association Football (NDAF): Systematic Review and Meta-Analysis.

There is increasing concern that head injuries in Association Football (or soccer) may lead to adverse health outcomes. The aim of this study was to determine whether head impacts or injuries are associated with an increased risk of neurodegenerative disease. We performed a systematic search using PubMed, Embase, and Ovid (up to April 2025). Studies included investigated neurodegenerative diseases in football in comparison to control athletic and general populations. Data were extracted according to PRISMA guidelines. Studies with an odds ratio (OR) were included in the meta-analysis. A total of ten studies were included in this review, of which nine were suitable for meta-analysis from eight cohorts. The risk for developing any neurodegeneration was 1.69 OR (95%CI 1.11 to 2.59; p = 0.01); for Dementia, it was 2.16 OR (95%CI 1.60 to 2.93; p < 0.01; for Motor Neurone Disease (MND), it was 1.39 OR (95%CI 0.67 to 2.53; p = 0.21); for Parkinson's Disease (PD), it was 1.14 OR (95%CI 0.55 to 2.89; p = 0.79). Heterogeneity was reduced following the removal of two studies and the revised risk scores for any neurodegenerative disease; Dementia increased, with that for MND reaching significance, 1.81 OR (95%CI 1.22 to 2.30; p = 0.01), but there remained no association with PD. Evidence suggests that professional football significantly increases the odds of neurodegenerative disease.