The hypoglycemic potential of phenolics from functional foods and their mechanisms

Long-term postprandial hyperglycemia is a primary risk factor for developing chronic metabolic diseases such as obesity, type 2 diabetes, and cardiovascular disease. Chronic hyperglycemia induces the glycation of proteins, oxidative stress, inflammation and increases plasma insulin and lipid concentrations. Insulin resistance is the primary cause of postprandial excursions of blood glucose and lipids. Hyperglycemia can be treated by lowering dietary carbohydrates intake, digestion, and absorption. Various functional foods improve glucose metabolism by increasing insulin sensitivity and inhibiting α-glucosidase in the small intestine. Natural phytochemicals, especially active phenolics are good antioxidants and show anti-inflammatory action and regulate blood glucose. This review aimed to report on hypoglycemic properties of active phenolics from functional foods and their proposed anti-diabetic mechanisms. Nevertheless, further clinical trials are required to confirm the bioavailability, safety, and efficacy of phenolics, especially the dosage and duration of treatment, to avoid adverse effects and give better dietary recommendations.