Dementia Support Line
Head injury, sport and the risk of dementia
Repeated or severe head injuries that cause damage to the brain may increase the risk of dementia. These injuries can happen while playing sport.
Do head injuries increase the risk of dementia?
A head injury that causes damage to the brain is known as a traumatic brain injury. Repeated or severe traumatic brain injuries increase the risk of dementia.
More research needs to be done to understand how the type and frequency of the injury, and age of the individual influences the risk of dementia.
Contact sports such as football (soccer), American football and rugby have all been associated with dementia. There is some evidence that brain injuries and/or head impacts from playing contact sports may increase the risk of dementia.
This must be considered in the bigger picture of dementia risk. Physical activity is one of the best things to do when it comes to reducing the risk of dementia and a range of other health conditions.
What are traumatic brain injuries?
Traumatic brain injuries (TBIs) occur when the brain is damaged after a head injury or serious jolt to the head. TBIs are classified as mild, moderate or severe based on a person’s responsiveness after the injury, any amnesia they may experience and the length of time a person is knocked unconscious – if at all. Serious TBIs are mostly caused by:
- falls
- road traffic accidents
- assaults
It is important that people wear protective headgear in situations where there is a higher-than-normal risk of head injury – for example, riding a bike, working on a building site or horse riding.
Alzheimer’s Society’s advice for contact sports
Sports like football and rugby are loved by millions across the UK and enable people to keep active. We would not discourage anyone from playing football or rugby.
However, while researchers work to understand this important issue, contact sports must be played as safely as possible.
We must strike a balance between ensuring people play the sports they love to keep fit and active with many health benefits and doing so in a safe way.
Sports’ governing bodies should make every effort to reduce head injury risk. They also need to make sure that when head injuries occur, they are managed appropriately. It’s important that coaching staff know how to deal with concussions and other head injuries. They should also have a plan in place to make sure players get medical attention when they need it.
The general advice in concussion management across sports and activities is: ‘if in doubt, sit them out'.
Is heading a football linked to dementia?
Traumatic brain injuries in football are less common compared to some other sports. But head impacts are common in football through heading the ball.
We don’t know all the factors that might contribute to a professional sports player’s potential high risk of dementia in later life. However, there have been calls by many to explore the role of brain injury and head impacts as possible risk factors.
Researchers believe that reducing exposure to head impacts when playing football might reduce risk. This is one reason why football associations have been reviewing heading in youth football.
Although much more work is required to demonstrate the exact link between heading and head impacts in football, evidence to date supports this could be a contributing factor.
Acknowledgements: With particular thanks to Professor William Stewart, Consultant Neuropathologist at Queen Elizabeth University Hospital and Dr Neil Graham, Consultant Neurologist and Clinical Lecturer at Imperial College London, for their support in developing this resource.
How to reduce the risk of dementia
A lifelong approach to good health is the best way to lower your risk of dementia.
There are some lifestyle behaviours with enough evidence to show that changing them will reduce your risk of dementia.
Dementia: Reducing your risk
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- Reduce your risk of dementia
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- Diabetes and the risk of dementia
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- Obesity and dementia risk
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- Depression and dementia risk
- You are here: Head injury, sport and the risk of dementia
- Air pollution and the risk of dementia
A group of world-leading researchers reviewed the highest quality research into the link between different factors and dementia risk.
Traumatic brain injuries were included in this list of risk factors we can modify or reduce by a group of international experts. The researchers called for measures to reduce brain injuries as this could potentially help reduce dementia.
In 2023, researchers analysed over 30 previously published studies looking at the risk of dementia after traumatic brain injuries. This study is the most comprehensive of its kind to date. They identified that someone who has had a traumatic brain injury is 1.6 times more likely to develop dementia than someone who hasn’t.
Although there is an association between traumatic brain injuries and increased risk of dementia, it’s also clear that not everyone who has experienced a brain injury or repeated brain injuries will go on to develop dementia.
We need much more research to better understand the nature of the association between traumatic brain injuries and risk of dementia, accurately predict who is likely to go on to develop dementia after a traumatic brain injury and how this is influenced by the nature, number and severity of injury and the age that it occurs.
Research has shown a connection between playing football (soccer) and dementia risk in professional players. This work, although very important, hasn’t yet pinpointed why this is the case.
Other research into professional rugby players found they have a two times increased risk of developing dementia later on in life.
Similar studies in former professional American football and ice hockey players reported similar increased risk of death from dementia in that population. However, whether this risk is repeated across other sports and in non-professional athletes is less well understood.
It is clear that there is an urgent need to accurately gather data relating to traumatic brain injuries (from mild to severe) in sport over time. We also need to see more research to understand any link between the number and type of injuries sustained during contact sport and developing dementia and what the underlying mechanism may be.
Chronic traumatic encephalopathy is a form of degenerative brain disease similar to Alzheimer’s disease. An abnormal form of the protein called tau accumulates in the brain, alongside other brain changes and, like in Alzheimer’s disease, people often have different brain changes.
There is currently no way to diagnose CTE in life. It can only be recognised after someone has passed away and their brain has been examined at a post-mortem examination. There are also no disease modifying treatments available for CTE.
CTE was first described as ‘punch drunk’ in former boxers almost a century ago and can lead to memory loss, changes in mood, confusion, disorientation and difficulty with thinking. It is uniquely associated with history of repetitive head impacts. While some people who sustain repeated head impacts will develop CTE, others will not and the reasons for this are unclear.
Microscopic changes in the brain associated with CTE can lead to dementia. Many studies have shown these changes in the brain in former footballers and rugby players who developed dementia.
There are various severity stages of CTE, ranging from small amounts of tau build up in specific areas in the brain, to large amounts of build-up affecting most areas of the brain. It’s thought the severity of CTE impacts the dementia symptoms someone might experience.
However, dementia is complex and there are also often other changes in the brain present alongside those associated with CTE, such as Alzheimer’s disease pathologies, and the final dementia diagnosis in these former athletes can be a range of disorders, not just CTE.
CTE pathology is uniquely linked to repeated head impact exposure so it’s likely a key factor in dementia risk in former athletes.
It is important to note that only some people who sustain repeated traumatic brain injuries will develop CTE. Others will not and the reasons for this are unclear. More research is needed to understand the risk of CTE, how it develops, who it affects and to develop treatments to slow or stop its progression.