The idea that Alzheimer’s disease might be a kind of diabetes has been floating around the research community for a number of years. Now it’s beginning to garner some media attention. Here is a 2008 paper that explains the hypothesis:
‘For nearly three decades of relatively intense research on AD, the inability to interlink this constellation of abnormalities under a single primary pathogenic mechanism resulted in the emergence and propagation of various heavily debated theories, each of which focused on how one particular component of AD could trigger a cascade that contributes to the development of all other known abnormalities. However, reevaluation of the older literature revealed that impairments in cerebral glucose utilization and energy metabolism represent very early abnormalities that precede or accompany the initial stages of cognitive impairment1 and led us to the concept that impaired insulin signaling has an important role in the pathogenesis of AD and the proposal that AD represents “type 3 diabetes.”’
This suggests that the behaviors that protect against diabetes may also protect Alzheimer’s disease.