JAMA Netw Open
Anemia linked to elevated dementia risk, biomarkers
Clinical takeaway: Low hemoglobin may be a clinically relevant risk signal in cognitive assessment for older adults at risk for dementia.
Anemia is common in later life, but its relationship to Alzheimer-related biology has been unclear. Prior studies have also linked anemia to higher dementia risk, but whether it tracks with blood-based markers of Alzheimer pathology and neurodegeneration has been less clear.
This study was designed to test whether low hemoglobin is associated not just with later dementia, but also with biomarker evidence of underlying brain pathology before dementia develops.
Investigators studied 2,282 dementia-free adults aged 60 years or older in a Swedish population-based cohort. They measured baseline hemoglobin and blood biomarkers tied to Alzheimer pathology, neurodegeneration, and glial activation, then tracked incident dementia over a mean follow-up of 9.3 years.
The main signal was a 66% higher dementia risk in participants with anemia vs. those with normal hemoglobin after adjustment for comorbidities and other factors. Anemia was also associated with higher baseline levels of phosphorylated tau 217, neurofilament light chain, and glial fibrillary acidic protein. Dementia risk was highest when anemia and elevated biomarkers coexisted, reaching an adjusted hazard ratio of 3.64 for anemia plus high neurofilament light chain.
The findings suggest anemia may track underlying neurodegenerative or Alzheimer-related processes rather than acting only as a general marker of poor health. It remains unclear whether correcting anemia would alter biomarker trajectories or lower dementia risk.
“Taken together, our findings suggest anemia is a clinically relevant factor in the context of dementia risk stratification and is possibly a modifiable target in dementia prevention strategies,” the authors conclude.
Source: Valletta M. JAMA Netw Open. 2026 Apr 17. Anemia and blood biomarkers of Alzheimer disease in dementia development