Blood biomarkers might signal Alzheimer’s risk long before symptoms emerge, offering a possible tool for early prevention.
A study based on data from the Finnish population reveals that indicators of Alzheimer’s disease can be present in the brain as early as middle age. In the years ahead, detecting Alzheimer’s-related biomarkers through blood samples could enable earlier diagnosis and make it possible to direct preventive interventions to those most likely to benefit, while symptoms are still minimal.
With an aging population, Alzheimer’s and other forms of dementia are increasingly widespread. However, the biological changes that drive these conditions often start long before any noticeable cognitive decline, including memory loss, begins to appear.
Biomarkers increase with age and may be inherited
Researchers at the University of Turku in Finland discovered that some individuals in middle age already show elevated levels of blood biomarkers linked to Alzheimer’s disease, with concentrations tending to rise as people get older.
One notable observation was that individuals whose parents—especially mothers—had high biomarker levels were more likely to exhibit elevated levels themselves in midlife. The study also revealed a possible connection between kidney disease and increased biomarker concentrations during middle age.
While the APOE ε4 gene is known to raise the risk of Alzheimer’s, its association with higher blood-based biomarker levels was only seen in older adults, not yet in those who are middle-aged.
A blood sample will help diagnose Alzheimer’s disease in the future
Recently, it has become possible to identify biomarkers associated with Alzheimer’s disease through a blood sample. In the future, this offers a cost-effective method for identifying those at greatest risk of developing Alzheimer’s disease and prioritizing them for preventive treatments.
“In clinical practice, detecting beta-amyloid pathology associated with Alzheimer’s disease currently requires imaging studies or cerebrospinal fluid sampling. However, recently developed ultrasensitive measurement technologies now allow the detection of Alzheimer’s disease-related brain biomarkers from blood samples,” says Suvi Rovio, Senior Researcher at the Research Centre of Applied and Preventive Cardiovascular Medicine at the University of Turku, who led the study.
More research needed for reliable interpretation
It is not yet possible to definitively diagnose Alzheimer’s disease with a blood sample, as the method is still limited by the lack of well-known reference values. Additionally, it remains unclear which confounding factors influence biomarker concentrations in blood related to Alzheimer’s disease. Therefore, the interpretations of the biomarkers obtained from blood sample could lead to misdiagnosis.
“In order to reliably use blood-based biomarkers for Alzheimer’s disease diagnosis in the future, more research is needed across different population and age groups to standardize reference values,” highlights Rovio.
In the study, biomarkers associated with Alzheimer’s disease were measured from blood samples of middle-aged participants (aged 41–56) and their parents (aged 59–90), with a total sample size of 2,051 individuals.
“Until now, brain biomarkers associated with Alzheimer’s disease have mainly been studied in older individuals. Our study provides new insights into biomarker levels and associated factors starting from middle age,” says Marja Heiskanen, Senior Researcher at the Research Centre of Applied and Preventive Cardiovascular Medicine at the University of Turku.
Reference: “Factors related to blood-based biomarkers for neurodegenerative diseases and their intergenerational associations in the Young Finns Study: a cohort study” by Marja A Heiskanen, Juha Mykkänen, Katja Pahkala, Markus Juonala, Mika Kähönen, Terho Lehtimäki, Tomi P Laitinen, Eero Jokinen, Päivi Tossavainen, Anna Linko-Parvinen, Hanna-Mari Pallari, Kaj Blennow, Henrik Zetterberg, Jorma Viikari, Olli Raitakari and Suvi P Rovio, June 2025, The Lancet Healthy Longevity.
DOI: 10.1016/j.lanhl.2025.100717
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2 Comments
Thanks ive had symptoms since I came home from college at 19
Personally, not scienze related, although I am a retired R.N,. and know this has to be provenienti by siece, I will forever believe this has to be as roven here, that “A” is definitely passed down through families. My husbands mother had this disease his siser had this disease and my husand had this disease. My sister-in–la was an R.N. and lived in Washington state, I lived in R.I. as a result I had no real contact, other than the phone. She did call me and farlo often. During those conversations she would always tell me how afraid.she was that she was losing her mind. She would then go on to tell me things that she had done or trouble she she had and how afraid she was that she was going to end up just like her mother. I remember one time she got in her car drove to the end of her street and had to turn around and go home because she couldn’t remember where she was going. She lived alone, but had 6 children all nearby and involved to various degrees.