To understand the causal relationship between these two diseases, we investigated whether there is a mechanistic link between two key observations, namely elevated levels of D-ribose in T2DM on the one hand (Su & He, 2014) and Tau hyperphosphorylation, an early event in the development of age-related dementia during progression of AD, on the other. This evidence concerns the gene MAPT and type 2 diabetes mellitus.