A NEW study has revealed that anaemia in later life was strongly associated with biological markers of Alzheimer’s disease and a significantly increased risk of developing dementia.
Anaemia, characterised by low haemoglobin levels, has long been linked to poorer cognitive outcomes, but its relationship with underlying Alzheimer’s pathology has remained unclear.
The latest findings suggest that anaemia may not only be a risk factor but could also interact with key neurodegenerative processes that drive dementia progression.
Anaemia, Dementia Risk, and Alzheimer’s Biomarkers
In this large cohort study of 2,282 dementia-free adults aged ≥60 years, researchers analysed blood samples alongside long-term cognitive outcomes. Participants were followed for a mean of 9.3 years, during which 15.9% developed dementia.
Individuals with anaemia showed significantly higher levels of key Alzheimer-related blood biomarkers at baseline, including phosphorylated tau 217 (p-tau217), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP).
Crucially, anaemia was associated with a 66% higher risk of developing dementia compared with normal haemoglobin levels (hazard ratio: 1.66; 95% CI: 1.21–2.28).
The risk was even more pronounced when anaemia coexisted with elevated biomarkers, with some groups showing more than a threefold increase in dementia risk.
Long-Term Data Strengthens Clinical Relevance
The study drew on data from a well-established population-based ageing cohort, with repeated follow-ups and robust diagnostic criteria for dementia. Researchers used advanced statistical models to assess both cross-sectional biomarker associations and longitudinal dementia risk.
These findings suggest a potential biological pathway linking reduced oxygen-carrying capacity to neurodegeneration. Reduced haemoglobin may contribute to cerebral hypoxia, a mechanism that has been proposed to accelerate neuronal injury and pathological protein accumulation.
Implications for Prevention and Future Research
The results highlight anaemia as a potentially modifiable risk factor in dementia prevention strategies. Routine screening and management of low haemoglobin in older adults could offer a simple avenue to reduce long-term cognitive decline.
Future research is needed to determine whether treating anaemia can directly lower dementia risk or slow disease progression.
Nonetheless, the study provides compelling evidence that systemic health factors such as anaemia may play a more central role in neurodegenerative disease than previously recognised.
Reference
Valletta M et al. Anemia and blood biomarkers of Alzheimer disease in dementia development. JAMA Netw Open. 2026;DOI:10.1001/jamanetworkopen.2026.4029.
Featured image: SewcreamStudio on Adobe Stock
