This was found in a recent longitudinal study on people aged 75 and above. It was also seen that there is a dose- response relationship between Hb levels and risk of dementia. Or in other words, the lower the Hb concentration the higher the risk for developing dementia. The researchers suggest that a chronic hypo-oxygenation of the brain due to a decreased oxygen carrying capacity of the blood could be the biological mechanism behind their findings.

It was only in persons with an initially good cognitive function that anemia increased the risk of dementia. No such association was found in persons with lower cognitive function at the start of the study. This suggests that anemia only plays a role in the initial stages of the disease. It also supports the idea that anemia is a cause of dementia and not an effect of it.

The relationship between anemia and dementia seems to be independent of other chronic conditions potentially related to anemia and dementia since this was adjusted for in the study.