New research from the University of Eastern Finland explores the role of diabetes in the cellular and molecular changes underlying Alzheimer’s disease (AD). In an AD mouse model, diabetes induced through a diet rich in fats and sugars weakened the accumulation of microglial cells around amyloid plaques and increased the formation of neuritic plaques with prominent tau pathology. Besides the mouse model, a similar observation was also made in hydrocephalus patients with type 2 diabetes, who had fewer microglia around amyloid plaques than patients without diabetes. The findings provide valuable new insight into the cellular mechanisms by which type 2 diabetes contributes to the risk and development of AD.