(Portland, OR) -- Researchers have found a new cause of Alzheimer's Disease and vascular dementia. A new study led by scientists Oregon Health and Science University found that iron-rich cells in the brain destroy cells that are supposed to help clean connections between nerves. Researchers say it's surprising this wasn't found during previous research. They found it using a new technique to isolate the cells. The hope is that pharmaceutical manufacturers can now use this information to create drugs that can prevent that type of damage.