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Grape Polyphenols and Second-meal Effect (GRAPESECOND)

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ClinicalTrials.gov Identifier: NCT03741218
Recruitment Status : Recruiting
First Posted : November 14, 2018
Last Update Posted : March 13, 2019
Sponsor:
Collaborator:
California Table Grape Commission
Information provided by (Responsible Party):
Jara Pérez-Jiménez, National Research Council, Spain

Brief 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.

Condition or disease Intervention/treatment Phase
Obesity Other: Freeze-dried grape (GRAP)/Placebo (PLA) Not Applicable

Detailed 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).


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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 25 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Intervention Model Description: GRAP: dried and milled grape pomaces. PLA: control period. All the subjects will pass the two periods: one half will receive the acute PLA supplementation followed by the acute GRAP supplementation, and the other half will do it inversely. The assignment to each order will be done randomly. Both period will be separated by a two weeks washing period.
Masking: Double (Participant, Care Provider)
Masking Description: GRAP and PLA will have the same aspect, so neither the participant and the care provider will know the received treatment at each stage.
Primary Purpose: Basic Science
Official Title: Potential Modulatory Effect of Whole Grape on Second-meal Tolerance in Obese Subjects: Role of Polyphenols
Actual Study Start Date : December 10, 2018
Estimated Primary Completion Date : August 2019
Estimated Study Completion Date : March 2020

Arm Intervention/treatment
Experimental: 1
All subjects will receive a high-fat breakfast and a medium-fat lunch twice. They will consume together with the breakfast the placebo (PLA) the first time and grape (GRAP) the second time.
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).

Experimental: 2
All subjects will receive a high-fat breakfast and a medium-fat lunch twice. They will consume together with the breakfast grape (GRAP) the first time and the placebo (PLA) the second time.
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).




Primary Outcome Measures :
  1. Postprandial glucose (300-420 min) [ Time Frame: Up to two months ]
    Changes of postprandial blood glucose as result of supplementation with grapes, measured area under the curve for the period 300-420 min


Other Outcome Measures:
  1. Postprandial glucose and insulin [ Time Frame: Up to four months ]
    Changes of blood glucose (0-320 min) and insulin (0-300 and 300-420 min) as result of supplementation with grapes

  2. Plasma triglycerides [ Time Frame: Up to four months ]
    Changes of plasma triglycerides (0-300 and 300-420 min) as result of supplementation with grapes

  3. Plasma uric acid [ Time Frame: Up to four months ]
    Changes of plasma uric acid (0-300 and 300-420 min) as result of supplementation with grapes

  4. Plasma antioxidant capacity [ Time Frame: Up to five months ]
    Changes of plasma antioxidant capacity (0-300 and 300-420 min) as result of supplementation with grapes

  5. Plasma viscosity [ Time Frame: Up to six months ]
    Changes of plasma viscosity (0-300 and 300-420 min) as result of supplementation with grapes.

  6. Satiety [ Time Frame: Up to three months ]
    Changes of satiety (0-300 and 300-420 min) as result of supplementation with grapes.



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Ages Eligible for Study:   18 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03741218


Contacts
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Contact: Jara Pérez-Jiménez, PhD +34 91 549 23 00 ext 231223 jara.perez@ictan.csic.es

Locations
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Spain
Institute of Food Science, Technology and Nutrition, National Research Council (ICTAN-CSIC) Recruiting
Madrid, Spain, 28040
Contact: Jara Pérez-Jiménez, PhD    +34915492300 ext 231406    jara.perez@ictan.csic.es   
Sponsors and Collaborators
National Research Council, Spain
California Table Grape Commission
Investigators
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Principal Investigator: Jara Pérez-Jiménez, PhD Institute of Food Science, Technology and Nutrition (ICTAN-CSIC)

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Responsible Party: Jara Pérez-Jiménez, Principal Investigator, National Research Council, Spain
ClinicalTrials.gov Identifier: NCT03741218     History of Changes
Other Study ID Numbers: HRG_2018
First Posted: November 14, 2018    Key Record Dates
Last Update Posted: March 13, 2019
Last Verified: March 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Jara Pérez-Jiménez, National Research Council, Spain:
Polyphenols
Obesity
Grape
Postprandial
Insulin resistance
Second meal effect