Suffered a serious blow to the head? You could be at greater risk for Alzheimer’s disease—even 50 years later, finds a new study from researchers at Mayo Clinic.
The study team conducted brain scans of roughly 600 older adults, 141 of whom had the types of mild memory or thinking problems commonly associated with the early stages of Alzheimer’s. Among those who’d suffered a concussion severe enough to cause loss of memory or consciousness and who also showed signs of cognitive decline, levels of a type of brain plaque called “amyloid” were 18% higher than among people who’d never suffered a concussion.
“High levels of brain amyloid is a significant risk factor for Alzheimer's disease,” explains study coauthor Michelle Mielke, PhD, of Mayo Clinic’s epidemiology division. And so this concussion-amyloid connection suggests a link between head trauma and Alzheimer’s. That said, some people without a history of concussion also had elevated amyloid levels—which means a previous head trauma will not definitely result in memory problems or Alzheimer’s disease later in life, says Dr. Mielke.
This new research builds on previous studies that have found correlations between head injuries and Alzheimer’s, Dr. Mielke and her coauthors say. It’s possible that concussions increase the buildup up amyloid plaques, which in turn contribute to Alzheimer’s disease risk.
“This study is a step forward in helping us to understand the mechanisms by which head trauma is associated with risk of Alzheimer's disease,” Dr. Mielke says. They hope that their research will inform future studies and the development of more-effective Alzheimer’s treatments.
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