Acute Inflammatory and Metabolic Effect of High Fructose Intake

Fructose consumption is associated with the development of metabolic diseases and low-grade inflammation. However, the acute effect of a single meal rich in fructose on the metabolic and inflammatory response is not fully understood. This study will to evaluate the acute metabolic and inflammatory effect caused by a meal containing fructose overload. This will be a three-arm crossover, randomized, double-blind clinical trial. Participants will undergo the three interventions for random order: (i) standardized meal plus sucrose overload; (ii) standardized meal plus glucose overload; (iii) standardized meal plus fructose overload. During the washout period (7 to 21 days), the subjects will instructed to maintain their usual eating behavior and physical activity. On the day of each intervention, participants will to the outpatient clinic in the morning after an overnight fast. Anthropometric data (weight, height, and waist circumference) will collected. Body composition will evaluated using bioimpedance (Quantum® apparatus, RJM Systems, Michigan) and blood pressure and heart rate (digital monitor, model HEM705CP®, Omron) will measured after 30 minutes of rest. A catheter with a three-way stopcock will inserted into the arm of the volunteers. Blood samples (5mL) will collected after overnight fasting (baseline) and 30, 60, 120, and 240 minutes after the standardized meal containing sucrose or glucose or fructose overload. Participants will remain seated throughout the evaluation period. Participants will receive a standardized meal of bread, ham, and margarine plus a sweetened drink (200mL) with similar amounts of different carbohydrates (sucrose, glucose, or fructose) in each intervention. The meals will provide 25% of the energy requirements, calculated from the resting energy expenditure measured by indirect calorimetry (KORR®, MetaCheck) multiplied by the activity factor plus 10% referring to the thermal effect of food. The meal will consiste of 15% of protein, 30% of fat, and 55% of carbohydrate (30% of complex carbohydrates and 25% of sucrose or glucose or fructose). Serum levels of glucose, triglycerides, total cholesterol, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) will be measured by colorimetric enzymatic test. Serum levels of adiponectin, leptin, resistin and TNF will be measured by Enzyme Linked ImmuneSorbent Assay (ELISA). Serum levels of IL-2, IL-4, IL-5, IL-6, IL-10, IL-17, IFN-γ and eotaxin will be obtained by the Cytometric Bead Array (CBA).