US study of war veterans ties brain injury to dementia risk
PARIS - A large study in older veterans raises fresh concern about mild brain injuries that hundreds of thousands of troops have suffered from explosions in recent wars. Even concussions seem to raise the risk of developing Alzheimer’s disease or other dementia later in life, researchers found.
Closed-head, traumatic brain injuries are a legacy of the Afghanistan and Iraq wars. Body armor is helping troops survive bomb blasts, but the long-term effects of their head injuries are unknown.
Other research found a possibly high rate of mild cognitive impairment, or “pre-Alzheimer’s,’’ in some retired pro football players, who take many hits to the head in their careers.
The studies, reported yesterday at the Alzheimer’s Association International Conference in France, challenge the current view that only moderate or severe brain injuries predispose people to dementia.
“Even a concussion or a mild brain injury can put you at risk,’’ said Dr. Laurie Ryan, a neuropsychiatrist who oversees Alzheimer’s grants at the US National Institute on Aging.
This doesn’t mean that every soldier or student athlete who has had a concussion is in danger. Pro football players and boxers “are almost a different species from us’’ in terms of the repeated blows they take to the head, said William Thies, the Alzheimer’s Association’s scientific director.
It does mean you should try to avoid one, by fall-proofing your home and wearing helmets and seat belts, he said. About 1.7 million brain injuries occur each year in the United States.
Troops need to prevent further harm, said Dr. David Cifu, national director of physical medicine and rehabilitation for the Veterans Health Administration.
“What the people who have had a head injury and read this should do is to exercise and eat right and take their medicines and take their aspirin and do meditation to reduce stress - reduce risk factors that are modifiable,’’ he said.
The new study is “a great start,’’ but limitations in its methods mean that it can’t prove a brain injury-dementia link, he said. More definitive studies are starting now but will take many years to give results.
The veterans study was led by Dr. Kristine Yaffe, a University of California professor and director of the Memory Disorders Clinic at the San Francisco VA Medical Center. The Department of Defense and the National Institutes of Health paid for the work.
“It’s by far the largest’’ study of brain injury and dementia risk, she said. “It’s never been looked at in veterans specifically.’’
Researchers reviewed medical records on 281,540 veterans who got care at Veterans Health Administration hospitals from 1997 to 2000 and had at least one follow-up visit from 2001-2007. All were at least 55. This older group was chosen because dementia grows more common with age, and researchers needed enough cases to compare those with and without brain injuries.
Records showed that 4,902 of the veterans had suffered a traumatic brain injury, or TBI, ranging from concussions to skull fractures. Researchers don’t know how long ago the injuries occurred. Many participants were Vietnam War vets and their injuries were during active duty.