Dietary Polyphenols, Mediterranean Diet, Prediabetes, and Type 2 Diabetes: A Narrative Review of the Evidence

Figure 1

Relevant mechanisms linking dietary polyphenols and T2D risk. Polyphenols can exert a beneficial effect on type 2 diabetes by a number of mechanisms including (a) slowing carbohydrate digestion and glucose absorption by interacting with oral cavity and intestinal α-amylase and intestinal α-glucosidase and sodium-dependent glucose transporter (SLGT1); (b) stimulating insulin secretion in the pancreas via increasing 5′ adenosine monophosphate-activated protein kinase (AMPK) pathway, and insulin receptor substrate (ISRS) and decreasing β-cell oxidative damage which preserves β-cell integrity; (c) modulating liver glucose release due to increase in acyl-CoA oxidase 1 (ACO-1) and carnitine palmitoyl transferase 1-β (CPT1-β) and diminishing glucose 6 phosphatase (G6Pase) and phosphoenolpyruvate carboxylase (PEPCK); and (d) activation of glucose uptake receptors in the insulin-sensitive tissue. Additionally, the modulation of microbial metabolism can synergically benefit glucose homeostasis.