The Study
Plasma biomarker trajectories across Alzheimer’s clinical onset: a 17-year prospective study
This study watched people for many years and noticed that certain blood markers started changing about 10–15 years before they started having memory problems. It doesn’t prove those markers cause the problems, but they’re like early warning signs that show up before the symptoms do.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Scientists tracked blood markers in people who later got Alzheimer’s and found that certain proteins change in the blood many years before memory problems start.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 564 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this means a simple blood test could one day identify people at risk for Alzheimer’s long before they feel any memory issues, helping doctors start treatments earlier.
- 2p-tau181/Aβ42 changes first — 13 years before symptoms.
- 3GFAP changes at 12 years.
- 4Aβ42/Aβ40 changes at 11.5 years.
- 5NfL changes only at 5 years.
- 6GFAP also rises in other types of memory loss.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Alzheimer's Research & Therapy
Year
2026
Authors
Siqi Xie, Yumei Liang, Yana Pang, Ying Li, Shuman Cao, Yan Li, Qi Wang, A. Moghekar, Marilyn S. Albert, J. Jia, Barbara Rodzon, A. Soldan, C. Pettigrew, L. Farrington, M. Grega, Michael Miller, Susumu Mori, T. Ratnanather, Anthony Kolasny, Hanzhang Lu, Kenichi Oishi, Laurent Younes, Sara Ho, D. Shade, A. Ervin, Jennifer L. Jones, Hamadou Coulibaly, Meilun Wang, Yuxin Zhu, Jiangxia Wang, Juan C. Troncoso, David W. Nauen
Related Content
Claims (6)
Blood levels of neurofilament light chain rise 9 to 10 years before a person is diagnosed with Alzheimer's disease, indicating that nerve cell damage is already occurring.
In people who will later develop Alzheimer’s disease, the ratio of p-tau181 to Aβ42 in blood plasma starts to change more than 13 years before any symptoms of memory loss appear.
In people who will later develop Alzheimer’s disease, the ratio of two amyloid proteins in the blood drops about 11.5 years before memory problems appear. This change does not occur in people who develop other types of cognitive decline.
Specific proteins in the blood can identify Alzheimer’s brain changes more than ten years before memory problems appear, and the pattern of these protein changes is different in Alzheimer’s compared to other types of cognitive decline.
Plasma GFAP levels rise about 12 years before cognitive symptoms appear in people who eventually develop Alzheimer’s disease, and also rise in people who develop other forms of cognitive decline, showing that this biomarker is linked to general neuroinflammation, not Alzheimer’s-specific brain changes.
In people who will eventually develop Alzheimer’s disease, levels of neurofilament light chain in the blood rise about five years before they show signs of memory problems, and this change is linked to advanced nerve cell damage, not the earliest disease triggers.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.