Your Dementia Risk Doubles If You've Had This, New Study Says
Experiencing this one thing has been found to have serious long-term effects on the brain.
The idea of coping with dementia as we age can weigh heavily on someone with a family history or another known risk factor of the condition. Unfortunately, it's a growing problem: According to the Centers for Disease Control and Prevention (CDC), the number of people diagnosed with cognitive decline is expected to increase from a 2014 estimated count of 5 million to nearly 14 million by 2060. But through planning with your doctor, it's possible to address the immediate health issues that could increase your likelihood of developing the condition, such as high blood pressure, high cholesterol, or a smoking habit. But according to new research, having experienced one thing can automatically double your dementia risk. Read on to see what could be a culprit in causing cognitive decline.
Having had a mild brain injury or concussion could double the risk of developing dementia.
In 2018, a team of researchers working with the U.S. Department of Veterans Affairs (VA) set out to better understand the connection between traumatic brain injury (TBI) and dementia in veterans, focusing in particular on how even mild TBI that didn't result in a loss of consciousness could affect the likelihood of developing the condition. The team analyzed data from the Veterans Health Administration health care system from October 1, 2001, to September 30, 2014, carefully matching 178,779 veterans who had been diagnosed with having suffered TBI with 178,779 who had not, of which 90.3 percent overall were men with an average age of about 49.5 years old. The study also excluded any patients who had already been diagnosed with dementia at its outset.
Results found that 4,698 veterans who had not experienced TBI—or 2.6 percent—developed dementia compared with 10,835—or 6.1 percent—of those who had suffered a mild head injury. When adjustments were made for medical histories or complications, the researchers concluded that "even mild TBI without loss of consciousness was associated with more than a 2-fold increase in the risk of dementia diagnosis."
Experts have been trying to better understand the connection between head injuries and dementia.
The relationship between brain injuries and dementia is one that is becoming more closely studied. According to the Alzheimer's Association, about 775,000 seniors are living with a TBI-related disability, which can commonly be caused by events ranging from a simple fall to a car accident. However, over the past three decades, the organization says that mounting research has drawn a connection between head trauma patients and the development of dementia later in life.
One study cited by the organization found that "older adults with a history of moderate traumatic brain injury had a 2.3 times greater risk of developing Alzheimer's than seniors with no history of head injury, and those with a history of severe traumatic brain injury had a 4.5 times greater risk." And in another study published in the online edition of the Journal of Neurology on March 23, 2016, it was found that "a history of [TBI] may accelerate the age of onset of cognitive impairment by two or more years," seeing similar results to other studies on the timeline between TBI and dementia.
Repeated mild brain injuries may be more likely to cause dementia than one larger trauma.
Researchers also point out that while there has been no research that links suffering one significant brain injury with an increased likelihood of dementia, some have found evidence that multiple mild TBI could play a factor. A form of dementia known as chronic traumatic encephalopathy (CTE)—described by the Mayo Clinic as "brain degeneration likely caused by repeated head traumas"—has recently gained attention, especially as it relates to people who regularly play high contact sports such as American football, boxing, soccer, and hockey.
The Alzheimer's Association reports that research on the condition in boxers—originally called dementia pugilistica or "punch-drunk syndrome"—has found that the incidence of dementia later in life was more correlated to the number of rounds boxed overall rather than the number of traumatic brain injuries suffered when knocked out unconscious during a fight. According to the Mayo Clinic, symptoms of CTE include cognitive issues such as memory loss or brain fog and behavioral changes that can affect aggression or impulsive decision making. It can also cause mood disorders such as depression or apathy, suicidal thoughts, or emotional instability, as well as motor-related symptoms similar to Parkinson's disease.
The original study's authors are advocating for more research and for patients to monitor their symptoms.
In the press release accompanying the original VA published research, the study's authors conclude that more work must be done to understand the relationship between brain injuries and dementia. They cite other work that has found TBI could be related to an increase in "toxic and abnormal proteins" in the brain over time, leading to developing cognitive decline.
Ultimately, the researchers say that while they can't conclusively establish that a single brain injury can be linked to an increased risk for dementia, they suggest that anyone who has had a recent head injury, a head injury in the past, or is concerned about a sudden change in their memory should contact their doctor.
"TBI is only one of many risk factors for dementia, including genetic markers, that are being studied," they conclude. "No matter what risk factors you may have, it's important to maintain an overall healthy lifestyle, monitor your heart health, and try to remain mentally and physically active."