Effects on Glycemia and Insulinemia of Different Grape Varieties

The main purpose of this study is to evaluate how the glucose and insulin curves develop after consuming different grapes varieties. Still, we also want to evaluate how the serum metabolome changes with the three varieties after 120 minutes. Therefore, a metabolomic study will be done in samples of volunteers at this time point.

The intervention is longitudinal and in three arms (one per variety). Due to the harvest of the different varieties, it cannot be crossover, but each subject will consume the three varieties.

At each visit, the subjects will undergo the same schedule:

• Arrival in a fasting state of at least 8 hours.
• Insertion of cannula and extraction of fasting samples
• Consumption of approximately 300 g of grapes (50 g of Carbohydrates).
• Extraction of blood samples at 15, 30, 60, 90 and 120 minutes.

Inclusion criteria

• Baseline glycaemia between 70 and 100 mg/dL
• BMI between 18.5 kg/m2 and 29.9 kg/m2.
• Absence of disease or alterations related to gastrointestinal status.
• Signed written informed consent.

Exclusion criteria

• Glycaemic levels out of the reference inclusion criteria (below 70 or over 100 mg/dL)
• Subjects presenting BMI out of the limits set.
• Subjects with unstable body weight the three months prior the start of the study (+/- 3 Kg)
• Subjects not able to attend the preestablished visits
• Women pregnant or lactating
• Subjects undergoing pharmacological treatment