Blood Test Predicts Dementia Risk Decades Early

A significant advancement in early dementia detection may be on the horizon, with a recent study suggesting that a blood test can predict the risk in women up to 25 years in advance. Published in the Journal of the American Medical Association, the research focused on the protein plasma phosphorylated tau 217 (p-tau217), a known biomarker for Alzheimer's disease.

The study, which followed 2,766 women aged 65 to 79 for up to 25 years, found a clear association between elevated baseline levels of p-tau217 and the subsequent development of mild cognitive impairment or dementia. This suggests a potential for identifying high-risk individuals long before cognitive symptoms manifest.

Interestingly, the predictive power of p-tau217 was found to be greater in women undergoing estrogen plus progestin hormone therapy compared to a placebo. Larger associations were also observed in women over 70 and those carrying the APOE ε4 gene, a known risk factor for Alzheimer's.

Despite these promising findings, the study acknowledged certain limitations. The research cohort consisted solely of older women, and dementia was not analyzed by specific subtypes. Furthermore, the smaller sample size of Black women compared to white women may have influenced the results, with p-tau217 associations showing differences between racial groups.

Experts suggest that while this blood test shows great potential for early risk assessment in specific populations, it may not be a universal solution. Further research is needed to identify subgroups for whom these plasma markers are most predictive and to address potential disparities across different demographics. The study concluded in 2021.