PARIS -- Head injuries may more than double the risk of dementia in military veterans, a study found.
The dementia risk was 15.3 percent among U.S. veterans who had sustained a traumatic brain injury, compared with 6.8 percent for those who didn't suffer head trauma, over a seven-year period. The risk was significant for all forms of traumatic brain injury, or TBI, according to researchers, who reviewed medical records of 281,540 veterans ages 55 and older.
The findings, presented at the Alzheimer's Association International Conference in Paris on Monday, highlight another potential hazard of war. Traumatic brain injury is a "signature wound" of the conflicts in Iraq and Afghanistan, accounting for 22 percent of casualties overall and 59 percent of blast-related injuries, said Kristine Yaffe, director of the Memory Disorders Program at the San Francisco Veterans Affairs Medical Center and a professor of psychiatry at the University of California, San Francisco, who led the research.
"This issue is important because TBI is very common," Yaffe said in a statement. "The data suggest that TBI in older veterans may predispose them toward development of symptomatic dementia. And they raise concern about the potential long-term consequences of TBI in younger veterans."
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Soldiers increasingly suffer from serious head injuries as a result of changes in warfare technology, said William Thies, chief medical and scientific officer of the Alzheimer's Association.
A separate study, also presented Monday, found that former players in the National Football League were at higher risk for mild cognitive impairment, according to the Alzheimer's group.
"It's pretty conclusive that there is an association between serious head injury and dementia," Thies said in an interview in Paris.
"What we can anticipate is that in all those soldiers coming back from Iraq and Afghanistan, 20 years from now we are going to see a big increase in the amount of Alzheimer's that's going to develop."
The incidence of dementia in younger soldiers means patients may live longer with the memory-robbing illness.
"If they have certain kinds of behavioral problems because they are younger and more functional they will actually become more dangerous patients to handle," Thies said.
The study of former NFL players found that retired athletes were clearly impaired compared with a similar group of non- athletes, according to a statement from the Alzheimer's Association.
Retired players with mild cognitive impairment were also significantly younger on average than non-athletes with impairment, according to the statement.
Further studies are needed to confirm the finding, he said in the statement.
More than 5 million Americans have Alzheimer's disease, which disrupts memory, learning and mental function, according to the Alzheimer's Association. By 2050, as many as 16 million Americans will have the disease, said the advocacy organization, which is based in Chicago.