EFFECT OF SUGAR VS MIXED BREAKFAST ON PLASMA GHRELIN AND P-300 POTENTIALS

ABSTRACT Background: Obesity is a health emergency growing worldwide. The hallmark of obesity is an augment in visceral fat. Alongside waist circumference gain, impaired blood lipid profile and hypertension it leads to Metabolic Syndrome (MetS). Amongst the several factors contributing to its spread, breakfast consumption plays a role promoting ghrelin regulation. In addition, breakfast consumption may ameliorate cognitive performance. Aim: We focused on how three different commercial breakfasts, with different contents of macronutrients, affected: 1) metabolic response and sense of satiety via ghrelin regulation (protocol M); 2) cognitive processing of sensory information via P300 recording (protocol N). To our purposes, we administered three different commercial breakfasts and glucose, as control, to 12 healthy subjects (6M/6F; 22.2±1.5 Kg/m2; 27±5 yo) who underwent two different experimental protocols to assess aim 1 and 2. Aside control (A 50gr glucose) The commercial breakfasts were as follows: B1) milk (125mL) and cornflakes (30gr); B2) milk (220mL), apple (200gr) and chocolate cream filled sponge cake (30gr) and B3) milk (125mL), apple (150gr), bread (50gr) and hazelnut-chocolate cream (15gr). Protocol M: each subject went through one Oral Glucose Tolerance Test (50gr-OGTT) and three-meal test loads (one for each tested breakfast). We collected blood samples at -15’; 0; 15’; 30’; 45’; 60’; 75’; 90’ and 120’. Volunteers ate breakfast after the second blood sampling. We assayed glucose, insulin and ghrelin plasma levels (total). Protocol N: in four different days, each subject underwent eight evoked related potentials measurement (ERPs), two for each breakfast (one after a night fast and one three hours after breakfast consumption). To our purposes, we recorded frontal zone (FZ) ERPs latencies. Results: metabolic data showed that all three commercial breakfasts gave a significant lower glycemic response when compared to glucose (B1: p=<0.05; B2, B3: p<0.01) alongside a lower insulin response (only breakfasts B1 and B2 in a significant fashion: p<0.01). Ghrelinemia inhibition tended to be greater in B3 group (332.1±30.2 pg/mL) with respect to A (420.6±44.2 pg/mL), but did not achieve statistical significance. Electrophysiological data showed that, three hours after ingestion, B1, B2 and B3 displayed a decrease in FZ ERPs latency when respect to A, thus only B3 in a significant way (p<0.01). Conclusion: we demonstrated that different breakfasts were able to elicit lower glycemic and insulin responses even with a greater carbohydrate content. B1, B2 and B3 groups displayed a tendency to maintain satiety via ghrelin inhibition. Furthermore, hazelnut-chocolate cream breakfast (B3) consumption decreased P300 latency, suggesting ameliorated cognitive performance.