INS and type 2 diabetes mellitus: This review aimed to provide a comprehensive overview of the relationship between coffee consumption and T2DM, with a particular focus on the major polyphenols found in coffee, such as chlorogenic acid and its structurally related hydroxycinnamic acids (caffeic, ferulic, p-coumaric, and sinapic acids), which influence key pathways involved in glucose homeostasis, insulin resistance, oxidative stress, and inflammation.