Sport and dementia

Existing evidence

Alzheimer’s Research UK collaborated with the Health Policy Partnership (HPP) in 2022 to undertake a landscape review in the field to understand the current evidence base, as part of a project to identify research gaps in the area of sport as it relates to brain health and dementia risk reduction. This is an area where the research evidence is still emerging, and where data is incomplete or relies on self-reporting. This means that current findings are not always clear cut and can be open to a range of interpretations. While further research is clearly needed, it is important that where there is evidence of risk, this is used constructively in relevant sports to minimise risk.

Most existing research in this field has focused on elite male athletes, but other groups may be at different risk of long-term neurological damage. Hundreds of millions of people are actively involved in sports around the world, of whom elite males represent only a small proportion. There are important health benefits from participating in sport which may not confer the same risk as for elite athletes. It is becoming increasingly clear that females and adolescents display different risk, injury and recovery patterns to adult males, and therefore require dedicated research, support and policy interventions in the future. Furthermore, each sport has a unique risk profile that needs to be better understood.

Based on our evidence review (in preparation for peer review publication), we summarise the findings for the three sports with the greatest amount of evidence into the relationship between head injury and long-term neurological impact:

Rugby

Rugby has the highest rate of concussion in comparison with other sports at all levels, and there is growing evidence for the association between rugby-related concussions and associated longer-term cognitive conditions. Male Scottish former international rugby union players are over 2.5 times more likely to develop neurodegenerative disease (which includes diseases that cause dementia, motor neuron disease and Parkinson’s disease) than the general population[6].

Other studies have shown poorer cognitive function for people over 80 years old who had more than three concussions during their rugby career. A study which tested for cognitive impairment found a prevalence of 2-17% among rugby players compared to 3% in a comparison group.

Boxing

Men who have boxed have more than twice the risk of developing Alzheimer-like impairment than those who have never boxed. A history of boxing was associated with developing dementia an estimated 4.8 years earlier, and men in the Caerphilly Prospective Study who had boxed seriously when they were younger were more than twice as likely to display cognitive impairment compared to men with no history of boxing[7].

Different types or styles of boxing may confer different risk due to varying length of rounds and approach. Many studies combine multiple combat or fighting sports and do not break down analysis by discipline or subdiscipline, and so further research into the risk of different types of boxing is required.

Football

A study of former Scottish professional football players found a 3.5 times increased risk of death from neurodegenerative diseases and 4.9 times more frequent prescriptions of dementia medications in comparison with a control group. Studies have found that retired footballers are more likely to have neurodegenerative disease, including Alzheimer’s disease, be prescribed dementia medications, have mild cognitive impairment and have higher mortality from neurodegenerative disease than their non-footballer peers. There have also been several post-mortem diagnoses of CTE in former professional football players.