A head injury can happen to anyone — from a fall, a car accident, or a hit to the head while playing sports. Sometimes, it causes a concussion or even loss of consciousness. While many people recover fully, researchers have been asking an important question:
Can head injuries increase the risk of dementia later in life? Based on current evidence, the answer is yes — especially when the injury is moderate or severe. Even mild injuries, if repeated over time, may raise the risk.
Dementia is a general term for memory loss, confusion, and problems with thinking that make daily life difficult. Alzheimer’s disease is the most common type, but there are others, including vascular dementia and a condition called chronic traumatic encephalopathy (CTE), which has been linked to repeated head injuries.
Many studies have looked at the long-term effects of traumatic brain injuries (TBIs). A 2018 study published in The Lancet Psychiatry followed nearly three million people in Denmark and found that individuals who had experienced a head injury were more likely to develop dementia than those who hadn’t.
The risk was highest in the first six months after the injury, but it remained higher than average for years afterward. The more severe the injury, the higher the risk.
Another major study published in JAMA Neurology in 2021 found that veterans with a history of head injury had a significantly increased risk of dementia, even after adjusting for other health issues. This included both single serious head injuries and multiple mild ones.
The study showed that the brain does not always bounce back fully from trauma, and some damage may slowly build up over time.
In the case of athletes, especially those in contact sports like boxing, football, or rugby, repeated blows to the head can lead to CTE.
This condition has symptoms similar to Alzheimer’s disease, including memory problems, mood swings, and confusion, often beginning years after the person stops playing. CTE has been seen in former professional athletes, but it may also affect others who experience repeated head trauma.
Scientists believe that head injuries may trigger changes in the brain that increase the buildup of abnormal proteins, like tau and beta-amyloid, which are involved in diseases like Alzheimer’s and CTE. Injuries may also reduce blood flow to the brain or lead to long-term inflammation, both of which can harm brain cells and increase the risk of cognitive decline.
However, it’s important to remember that not everyone who has a head injury will get dementia. Many factors play a role, including age, genetics, overall brain health, and lifestyle. For example, people who exercise regularly, eat a healthy diet, avoid smoking, and stay socially and mentally active may lower their overall risk — even if they’ve had a head injury in the past.
In summary, research clearly shows that head injuries — especially moderate to severe ones, or repeated mild ones — can increase the risk of dementia later in life. Protecting your head, whether through wearing helmets, preventing falls, or managing sports injuries properly, is an important step in protecting your brain health for the future.
If you’ve had a head injury and are concerned about memory or thinking problems, talk to your doctor. Early support and a healthy lifestyle can go a long way in keeping your brain strong as you age.
If you care about brain health, please read studies about how the Mediterranean diet could protect your brain health, and Omega-3 fats and carotenoid supplements could improve memory.
For more information about brain health, please see recent studies about antioxidants that could help reduce dementia risk, and higher magnesium intake could help benefit brain health.
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