Bioavailability of the Polyphenols Contained in a Red Grape Extract-based Drink and Their Metabolic Effects

Evaluation of the Bioavailability of Polyphenols From a Red Grape Extract-based Drink and the Acute Effects of Its Consumption on Glucose and Lipid Response During the Subsequent Meal

Randomized placebo-controlled crossover study during which participants undergo two different experimental days. The participants consume a red grape based- drink (polyphenols: 300 mg/100 ml and sugar: 9.8g/100 ml) or a placebo (no polyphenols and sugar: 9.8g/100 ml). After 3 hours they consume a test meal (905 kcal, 15% protein, 46% fat, 39% CHO). Blood samples are taken at fasting, over 3 hours after drink consumption and over 5 hours after the test meal to evaluate metabolic response. Fasting and 48h-urine are collected to evaluate bioavailability.

Inclusion Criteria:

• BMI >25 and <35 kg/m2
• Total cholesterol <250 mg/dl
• Triglyceride < 200 mg/dl.
• Fasting glucose <100 mg/dl

Exclusion Criteria:

• Cardiovascular events (IMA or stroke) in the 6 months prior to the study
• Kidney or liver failure
• Anemia (Hb <12 g/dl)
• Any chronic disease
• Intense physical activity
• Dietary supplements