Scientists from the University of Washington School of Medicine in St. Louis have found a possible explanation for why African-Americans appear to be more vulnerable to Alzheimer’s disease than white Americans. They published their findings in JAMA Neurology, a peer-reviewed medical journal.
The study of 1,255 people, including 173 African-Americans, found cerebrospinal fluid from African-Americans tended to have lesser amounts of tau protein, which is associated with Alzheimer’s. In healthy neurons, tau proteins bind to and stabilize microtubules, which help maintain the structure of cells. With Alzheimer’s, tau detaches from those microtubules and attach to other tau, forming tangles that block communication between neurons.
Curiously, though, lower levels of tau don’t seem to protect African-Americans from Alzheimer’s. According to Alzheimer’s Association, older African-Americans are more likely than white Americans to develop the disease. This leads to a natural question: If tau isn’t as prevalent in African-Americans, what’s causing Alzheimer’s?
“That is the million-dollar question right there,” said Dr. Liana Apostolova, a neurologist at IU Health.
Most of what scientists know about Alzheimer’s comes from studies of white Americans, limiting the scope of understanding for minorities. Apostolova said similar studies in the future will have to go further in finding out what causes the disease’s prevalence in African-Americans.
Even though the study doesn’t conclude what exactly is causing more dementia cases in African-Americans, Apostolova said it could still have consequences for how doctors handle diseases like Alzheimer’s. The approach traditionally involves decreasing the presence of tau, but that may not be as relevant for African-Americans if they already have a decreased level of the protein.
“It might have a huge impact on how we approach diagnosis in that population and how we treat those individuals,” Apostolova said.
Contact staff writer Tyler Fenwick at 317-762-7853. Follow him on Twitter @Ty_Fenwick.