Diet low in advanced glycation end products increases insulin sensitivity in healthy overweight individuals: A double-blind, randomized, crossover trial

Background: The consumption of advanced glycation end products (AGEs) has increased because of modern food processing and has been linked to the development of type 2 diabetes in rodents. Objective: We determined whether changing dietary AGE intake could modulate insulin sensitivity and secretion in healthy, overweight individuals. Design: We performed a double-blind, randomized, crossover trial of diets in 20 participants [6 women and 14 men; mean ± SD body mass index (in kg/m²): 29.8 ± 3.7]. Isoenergetic- and macronutrient matched diets that were high or low in AGE content were alternately consumed for 2 wk and separated by a 4-wk washout period. At the beginning and end of each dietary period, a hyperinsulinemic euglycemic clamp and an intravenous glucose tolerance test were performed. Dietary, plasma and urinary AGEs N^V-(carboxymethyl) lysine (CML), N^V-(carboxyethyl)lysin (CEL), and methylglyoxal derived hydroimadazolidine (MG-H1) were measured with the use of mass spectrometry. Results: Participants consumed less CML, CEL, and MG-H1 during the low-AGE dietary period than during the high-AGE period (all P < 0.05), which was confirmed by changes in urinary AGE excretion. There was an overall difference in insulin sensitivity of 22.1 mg · kg^-1 · min^-1 between diets (P = 0.001). Insulin sensitivity increased by 1.3 mg · kg^-1 · min^-1 after the low-AGE diet (P = 0.004), whereas it showed a tendency to decrease by 0.8 mg · kg^-1 · min^-1 after the high-AGE diet (P = 0.086). There was no difference in body weight or insulin secretion between diets (P = NS). Conclusions: A diet that is low in AGEs may reduce the risk of type 2 diabetes by increasing insulin sensitivity. Hence, a restriction in dietary AGE content may be an effective strategy to decrease diabetes and cardiovascular disease risks in overweight individuals.