Effect of Low-Glycemic Index Mediterranean Diet on AGEs (Nutri_AGEs)

Advanced glycation end products (AGE) result from a chemical reaction between the carbonyl group of reducing sugar and the nucleophilic NH2 of a free amino acid or a protein; lysine and arginine being the main reactive amino acids on proteins. Following this first step, a molecular rearrangement occurs, rearrangement of Amadori resulting to the formation of Maillard products.

Specialized receptors (RAGE, Galectin 3…) bind AGE. The binding to the receptor causes the formation of free radicals, which have a deleterious effect because they are powerful oxidizing agents, but also play the role of intracellular messenger, altering the cell functions. This role is especially true at the level of endothelial cells as the attachment of AGE to RAGE receptor causes an increase in vascular permeability. AGE binding to endothelium RAGE and to monocytes-macrophages, led to the production of cytokines, growth factors, to the expression of adhesion molecules, and the production of procoagulant activity. Increased permeability, facilitation of leukocyte migration, the production of reactive oxygen species, cytokines and VEGF suggest that the AGE could be an element of a cascade of reactions responsible for the diabetic angiopathy and vascular damages observed during aging and chronic renal failure. Recently, It's been proposed that balanced diets can limit the deleterious effect of AGE. For these reasons, the interest in preventive approaches complementary or alternative to cholesterol reduction should be one of the main objectives of cardiovascular research in the years to come. Already in the '70s the very low incidence of atherosclerotic diseases in Mediterranean countries (Greece and Southern Italy) and the importance of the "dietary factor" in such protection were noticed. Diets for people in these countries are, among other components, very rich in oleic acid, the main constituent of olive oil, with about 29% of daily caloric intake derived from monounsaturated fatty acids. Aim of this trial is to estimate the effect of a Low Glycemic Index Mediterranean Diet on AGE products.

Intervention in this arm consists in some general dietary advice about healthy dietary components, serving size and frequency of servings following the Italian official guidelines.

Intervention in this arm consists in a Low Glycemic Index Mediterranean Diet with indication about type of foods than can be consumed frequently (green foods), sometimes (yellow foods) and never (red foods)

Prescription of a Low Glycemic Index (less than 50) Mediterranean Diet with no more than 10% of total daily calories coming from saturated fats, high in monounsaturated fatty acids (MUFA) from olive oil and omega-3 polyunsaturated fatty acids (ω3PUFA), from both plant and marine sources

Inclusion Criteria: Subject enrolled in the Nutriep cohort assembled in 2005-2007 Exclusion Criteria: Not enrolled in the Nutriep cohort Pregnancy

Cozzolongo R, Osella AR, Elba S, Petruzzi J, Buongiorno G, Giannuzzi V, Leone G, Bonfiglio C, Lanzilotta E, Manghisi OG, Leandro G; NUTRIHEP Collaborating Group; Donnaloia R, Fanelli V, Mirizzi F, Parziale L, Crupi G, Detomaso P, Labbate A, Zizzari S, Depalma M, Polignano A, Lopinto D, Daprile G. Epidemiology of HCV infection in the general population: a survey in a southern Italian town. Am J Gastroenterol. 2009 Nov;104(11):2740-6. doi: 10.1038/ajg.2009.428. Epub 2009 Jul 28.

Hooper L, Abdelhamid AS, Jimoh OF, Bunn D, Skeaff CM. Effects of total fat intake on body fatness in adults. Cochrane Database Syst Rev. 2020 Jun 1;6(6):CD013636. doi: 10.1002/14651858.CD013636.