Grape Polyphenols and Second-meal Effect

Obesity Clinical Trial

— GRAPESECOND  

Official title:

Potential Modulatory Effect of Whole Grape on Second-meal Tolerance in Obese Subjects: Role of Polyphenols

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03741218
• Other study ID #: HRG_2018
• Status: Completed
• Phase: N/A
• Start date: December 10, 2018
• Est. completion date: February 15, 2020

Study information

• Verified date: February 2020
• Source: National Research Council, Spain
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The aim of this is study is to evaluate the effects of a single intake of grapes (a polyphenol-rich food) in postprandial metabolism in subjects with obesity, including a first intake (high-fat breakfast) after overnight fasting a second one (medium-fat lunch). Studies on the effects of polyphenols on postprandial (glucidic and lipidic) metabolism have commonly been performed in animal models and have used grape extracts, ignoring the whole pool of polyphenols present in grapes (extractable and non-extractable polyphenols). Besides, the contribution of polyphenols to the so-called second-meal effect has not been explored. It should be highlighted that this study aims to explore the potential beneficial role of fresh grapes, consumed as fruit; in order to ensure the stability of the product, they will be provided as freeze-dried milled material, but the amount received by the subjects could be incorporated into a common diet, being equivalent to 300 g of fresh grapes.

Description:

Twenty-five subjects with obesity will be were recruited. Detailed inclusion and exclusion criteria are provided below.

The subjects will receive, after overnight fasting, either a monodose of freeze-dried grapes (equivalent to 300 g of fresh grapes) or isocaloric placebo solved in water, together with a high-fat breakfast. Blood samples will be collected before the intake, up to 5 h after breakfast, then a medium-fat lunch will be provided and blood samples will be collected for three additional hours. Both interventions will be separated by two weeks. The following determinations will be performed in blood samples collected at different periods: glucose, insulin, triglycerides, uric acid, viscosity, antioxidant capacity. Additionally, a satiety test will be provided. It is expected that grape supplementation, as compared with an isocaloric placebo, causes significant modifications in all the parameters indicated. Nevertheless, the primary outcome of this study is the area under the curve for glucose after the second meal (300-420 min from basal time).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 25
• Est. completion date: February 15, 2020
• Est. primary completion date: November 1, 2019
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 70 Years

Eligibility

Inclusion Criteria:

• Obesity (BMI = 30-40 kg/m2).

Exclusion Criteria:

• Subjects with a pharmaceutical treatment set to modify blood pressure, lipid profile or glucose.

• Subjects with diagnoses of type 2 diabetes, cardiovascular diseases or thyroid diseases.

• Values above the following ones: glucose, > 115 mg/dL; triglycerides, > 350 mg/dL; total cholesterol, > 280 mg/dL; systolic blood pressure, > 150 mmHg; diastolic blood pressure, > 100 mmHg

• Previous bariatric surgery.

• Volunteers participating in other studies (currently or during last year) or weight loss plans.

• Pregnant or breastfeeding women.

• Adherence to vegetarian diets or usual consumption of dietary supplements.

Related Conditions & MeSH terms

• Obesity

Intervention

Other:
• Freeze-dried grape (GRAP)/Placebo (PLA)
The subjects will receive, after overnight fasting, either a monodose of freeze-dried grapes (equivalent to 300 g of fresh grapes) or isocaloric placebo solved in water, together with a high-fat breakfast. Blood samples will be collected before the intake, up to 5 h after breakfast, then a medium-fat lunch will be provided and blood samples will be collected for three additional hours. A total of 10 samples will be collected: 0-30-60-120-180-240-300-330-360-420 min. Both interventions will be separated by two weeks. Subjects will be instructed not to modify their dietary habits during the development of the study, but during the 72 h before each visit they will have to restrict the intake of polyphenol-rich foods (a detailed list will be provided).

Locations

Country	Name	City	State
Spain	Institute of Food Science, Technology and Nutrition, National Research Council (ICTAN-CSIC)	Madrid

Sponsors (2)

Lead Sponsor	Collaborator
National Research Council, Spain	California Table Grape Commission

Country where clinical trial is conducted

Spain, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Postprandial glucose and insulin	Changes of blood glucose (0-320 min) and insulin (0-300 and 300-420 min) as result of supplementation with grapes	Up to four months
Other	Plasma triglycerides	Changes of plasma triglycerides (0-300 and 300-420 min) as result of supplementation with grapes	Up to four months
Other	Plasma uric acid	Changes of plasma uric acid (0-300 and 300-420 min) as result of supplementation with grapes	Up to four months
Other	Plasma antioxidant capacity	Changes of plasma antioxidant capacity (0-300 and 300-420 min) as result of supplementation with grapes	Up to five months
Other	Plasma viscosity	Changes of plasma viscosity (0-300 and 300-420 min) as result of supplementation with grapes.	Up to six months
Other	Satiety	Changes of satiety (0-300 and 300-420 min) as result of supplementation with grapes.	Up to three months
Primary	Postprandial glucose (300-420 min)	Changes of postprandial blood glucose as result of supplementation with grapes, measured area under the curve for the period 300-420 min	Up to two months