Low Hemoglobin and Anemia Linked to Increased Dementia Risk: Study
Sweden: Researchers have found in a new study that lower hemoglobin levels are associated with a progressively higher risk of dementia over long-term follow-up. In the instant Swedish cohort study, anemia was also linked to elevated levels of Alzheimer’s disease biomarkers, including p-tau217 and neurofilament light chain. The risk of dementia was highest in individuals who had both anemia and abnormal Alzheimer ’s-related biomarkers, suggesting a potential combined effect on neurodegeneration.
The findings, published in JAMA Network Open, come from a large population-based cohort led by Martina Valletta and colleagues from the Aging Research Center at Karolinska Institutet and Stockholm University, Sweden. The study explored whether anemia in older adults is associated not only with dementia risk but also with circulating biomarkers that reflect Alzheimer’s disease pathology, neuronal damage, and glial activation.
For this purpose, the researchers analysed data from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K), including adults aged 60 years and older. A total of 2,282 dementia-free participants were included after exclusions. The median age was 72.2 years, with nearly two-thirds being women. Baseline hemoglobin levels were measured, and anemia was defined using World Health Organization criteria. Participants were followed for over nine years to track incident dementia cases.
The key findings of the study were as follows:
- At baseline, individuals with anemia had significantly elevated levels of blood biomarkers linked to neurodegeneration and Alzheimer’s disease, including phosphorylated tau 217 (p-tau217), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP).
- Higher p-tau217 levels indicated increased tau pathology, while elevated NfL reflected neuronal injury and higher GFAP levels suggested astroglial activation.
- These findings indicate that anemia may be associated with underlying neuropathological changes even before the onset of clinical dementia symptoms.
- During follow-up, a total of 362 participants developed dementia.
- Individuals with anemia had a significantly higher risk of developing dementia compared to those with normal hemoglobin levels.
- The risk of dementia was further increased when anemia was accompanied by elevated levels of Alzheimer’s-related biomarkers.
- Participants with both anemia and high NfL levels had more than a threefold higher risk of dementia compared to those without these combined factors.
These findings suggest a possible link between anemia and neurodegenerative processes, with low hemoglobin and abnormal Alzheimer’s-related biomarkers identifying individuals at particularly high risk. This indicates that anemia may contribute to or worsen underlying brain pathology.
The authors emphasize the need for routine hemoglobin monitoring in older adults as part of dementia risk assessment. Managing anemia may be a modifiable approach to delay or reduce cognitive decline, although further research is required to clarify the causality.
Overall, the study highlights the interplay between hematological health and neurodegeneration, offering valuable insights for early detection and prevention of dementia.
Reference:
Valletta M, Vetrano DL, Qiu C, et al. Anemia and Blood Biomarkers of Alzheimer Disease in Dementia Development. JAMA Netw Open. 2026;9(4):e264029. doi:10.1001/jamanetworkopen.2026.4029
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