Is the mortality rate caused by neurodegenerative diseases actually increased in professional football players? This was the conclusion of a retrospective cohort study recently published in The New England Journal. How can the risk be explained medically?
7676 former professional football players were compared with over 23,000 controls from the general population. During the observation period, which averaged 18 years, 1180 of the professionals (15.4%) and 3807 (16.5%) of the controls died. The evaluation of the causes of death provided interesting insights: up to the age of 70, the overall mortality was lower in the soccer group – but thereafter higher than in the general population. Cardiovascular mortality was significantly lower and lung cancer was also significantly less frequent. However, the rate of neurodegenerative diseases such as Parkinson’s disease, motor neuron disease, Alzheimer’s disease, and other dementias was significantly higher. Overall, 1.7% of the former football players had a neurodegenerative principal diagnosis recorded on the death certificate, but only 0.5% of the control group (p<0.001). The main diagnosis was Alzheimer’s disease. In the comparison group, the rate of Alzheimer’s-related deaths was 0.2%, whereas in the former footballers it was four times higher (0.8%). Accordingly, these also took more dementia medications than controls from the general population. Field players were prescribed these more frequently than goalkeepers. In contrast, in terms of mortality, gambling status made no difference.
If the lower overall mortality at younger ages and the lower rate of ischemic heart disease can still be explained by the protective effect of the sport on the cardiovascular system, on the other hand, no medical explanation can be found for the higher rates of neurodegenerative diseases. The hypothesis that head impacts and traumatic brain injury could lead to an increased risk of neurodegenerative diseases has been discussed in the past. In fact, Chronic Traumatic Encephalopathy (CTE) resulting from repetitive mild head injury in various sports (boxing, American football, Australian football, rugby, soccer, ice hockey) has already been described. This could be a possible explanation. This is because tauopathy is found in CTE just as it is in neurodegenerative diseases. However, further research is needed here to draw any actual conclusions.
Source: “Do professional football players have an increased risk of dementia?”, Oct. 30, 2019, German Neurological Society.
InFo NEUROLOGY & PSYCHIATRY 2019; 17(6): 5.
