Brain samples from Alzheimer's patients have elevated levels of loosely bound iron.

The amount of loosely bound iron was measured in frontal cortex and cerebellum from autopsy brain samples from Alzheimer's patients and from non-demented, age matched controls. It was found that the amount of total iron and of ferric iron in Alzheimer's brain tissues was significantly higher compared to control samples in both regions studied. Neither the ferrous nor the ferrous to ferric ratio were found to be changed. Since it is the loosely bound iron that is responsible for free radical reactions in vivo, these results are consistent with an increased free radical burden in Alzheimer's disease that leads to the progressive neurodegeneration seen in this disorder.