Study finds blood test measuring p-tau217 linked to higher risk of later cognitive decline

A Harvard-led study found that a blood test measuring p-tau217 levels may predict cognitive decline up to 10 years before symptoms appear, Fox News reported. Researchers tracked nearly 2,700 cognitively healthy adults with an average age of 70 for up to 10 years.

Individuals with very high p-tau217 levels faced an estimated 78 percent chance of developing cognitive impairment within 10 years and a roughly one-in-three chance within five years, the study showed.

Those with moderately elevated levels carried a 45 percent risk over 10 years. The study was presented at the Alzheimer's Association International Conference in London and published simultaneously in The Journal of the American Medical Association. The protein p-tau217 is a modified form of tau that forms tangles in the brain and is associated with memory loss.

The blood test supplied information beyond what standard brain scans and genetic testing can offer, according to the research team. Rachel Buckley, the study's lead author and an associate professor of neurology at Harvard Medical School, said the results offer some of the clearest evidence that dementia risk can be detected years before memory problems begin.

"Once verified, these blood tests could be used to recruit patients for clinical trials of treatments to prevent cognitive decline and dementia," Buckley said in a press release.

Maria Carrillo, chief science officer at the Alzheimer’s Association in Chicago, said identifying people at risk earlier could change how dementia is diagnosed, treated and potentially prevented. Earlier detection could allow people to begin interventions before symptoms develop, she told Fox News Digital.