A new study has shown that levels of certain proteins in the blood may carry early signals of memory decline and cognitive deterioration years before obvious symptoms appear. This finding could open a pathway for developing simpler tests to identify people who are at higher risk of cognitive problems related to Alzheimer’s disease and dementia.
Researchers at the Miller School of Medicine at the University of Miami found in this study that higher levels of a protein called “p-tau181” were associated with poorer performance on memory and cognitive tests six years later, although no clear association between this protein and memory was observed at the start of the study. This finding is particularly important given scientists’ belief that biological changes related to Alzheimer’s may begin years or even decades before symptoms such as memory loss emerge.
Study details and blood markers
This study, published in the journal “Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring,” included approximately 1,170 people with an average age of 73. The researchers examined four blood biomarkers in this research: p-tau181, Aβ42/40, GFAP and NfL. These markers are linked to various processes including Alzheimer-related proteins, activity of the brain’s supporting cells, and damage to nerve fibers. In contrast, the cognitive tests used in this study included measures of memory, language, executive functions and visuospatial skills.
Results six years later
The results of this research showed that NfL and GFAP proteins had the strongest association with cognitive performance at the study’s outset. But after six years, a different picture emerged; p-tau181 became more prominent, and higher levels of it were associated with lower scores in memory and overall cognition. Meanwhile, GFAP remained associated with poor memory, executive functions and general cognitive abilities.
Deirdre O’Shea, one of the study’s researchers, said that p-tau181 was not associated with memory performance at the first measurement, but this association appeared six years later. According to her, this suggests that some blood markers may provide information about future cognitive changes that are not observable in concurrent tests.
Tau protein accumulation; a known feature of Alzheimer’s
Abnormal accumulation of the “tau” protein is a known feature in the brains of patients with Alzheimer’s. This fact in recent years has prompted scientists to explore whether forms of this protein in the blood can be used to detect changes related to the disease. This research was conducted within that framework and attempts to show whether blood markers can be used as a low-cost, accessible tool to monitor cognitive health.
Can this test predict dementia?
Researchers caution against interpreting the results to mean that a blood test can definitively predict developing Alzheimer’s or dementia. This study primarily focused on declines in memory and cognition rather than directly predicting a future Alzheimer’s diagnosis. However, the results indicate that combining indicators such as p-tau181 and GFAP may in the future help identify people who are likely to experience cognitive decline in the coming years.
Clinical importance and future outlook
These findings could be an important step toward developing early diagnostic tools. Preclinical detection offers an opportunity for therapeutic interventions, lifestyle changes and management of risk factors. However, experts emphasize that there is still a long way to go before these markers become standard clinical tests and that longer-term studies are necessary to validate the reliability and accuracy of these methods. If ultimately confirmed, such tests could become part of routine examinations for older adults and help physicians identify at-risk individuals early.