A new study from the University of California, San Diego, suggests a simple blood test could help predict dementia decades before symptoms appear.
Researchers analyzed blood samples from more than 2,700 women between the ages of 65 and 79 who were part of a large national memory study that began in the late 1990s. They measured a protein in the blood called p-tau217 and then followed the women for up to 25 years to see who later developed dementia.
“We sought to determine whether this blood-based biomarker plasma p-tau217 could, whether it was associated with dementia risk in people who had no symptoms, who were cognitively healthy,” said Aladdin Shadyab, lead researcher and associate professor of public health at UC San Diego's Herbert Wertheim School of Public Health and Human Longevity Science.
“What we found was that women who had elevated levels of this blood-based biomarker named Plasma p-tau217 had threefold higher risk of incident dementia,” Shadyab said.
What makes the discovery promising, he said, is how easily the biomarker can be measured.
“With a simple blood test, we can detect whether someone has changes in their brain that indicate Alzheimer's disease,” he said.
Today, doctors usually rely on more complex tests to detect these brain changes.
“A cerebral spinal fluid test, which is invasive, or what's called PET imaging,” he said. “Those are more costly approaches.”
The test is not ready for routine use in doctors’ offices just yet, he said.
“What the value of this test is, is that it can screen people to see whether they would require further follow-up testing,” Shadyab said.
Further studies are needed to confirm these findings. For now, Shayab said this blood test shows promise for research on factors that increase dementia risk.
