Not any direct connection, but somehow all connected.. Bad Diet = Brain Damage

Here's an interesting quote:

Some work has suggested that cardiovascular risk factors such as type 2 diabetes and high blood pressure also could be risk factors for dementia and Alzheimer's disease. Specifically with regard to type 2 diabetes, insulin resistance and inflammation may be the mechanisms underlying the association, the researchers said.

Other cardiovascular risk factors, such as homocysteine, lipoprotein-associated phospholipase (Lp-PLA2), and C-reactive protein (CRP), also have been suggested as potential mediating factors in the relationship.