Acute Effects of Grape Seed Extract on Insulin Sensitivity and Oxidative Stress and Inflammation Markers.
Condition: Polyphenolic Compounds and Metabolism
MeSH terms: Insulin Resistance; Inflammation
Study type: Interventional

Summary: 
      The proposed study aims to investigate that consumption of grape seed extract (GSE) would
      improve antioxidant status and impaired insulin action following consumption of a
      pro-oxidative high carbohydrate, high fat (HCHF) meal in healthy human subjects.
    

Detailed description: 
      This study is a single-center, double blind, placebo-controlled, randomized, 2-arm,
      2-sequence, crossover study

      A planned sample size of 15 will be recruited into the study. This study will require one
      initial screening, one pre-study visit, two 6-hour study visits. The study will take 2-5
      weeks per subject to complete.

      The initial screening visit will provide subjects an Institutional Review Board approved
      consent document and determine subject eligibility through BMI calculated from height and
      weight measurements, vital signs, fasting blood glucose test (finger prick), lipid profiles
      (3 ml blood sampling via a butterfly needle device) and completion of a questionnaire related
      to general eating, health, and exercise habits.

      If subjects are willing and eligible to participate, a 3-day food record (2 weekdays and 1
      weekend day) will be instructed at the initial screening visit and collected at the pre-study
      visit to assess subjects' usual dietary intake pattern. After reviewing food records,
      subjects will be instructed to avoid any grapes, grape products, berries, berry products
      throughout the study and strictly follow a limited polyphenolic diet for 3 days prior to each
      6-hr study visit, while maintaining their usual diet pattern and physical activity. Prior to
      each study visit, subject will be advised to have the same or similar dinner meal to control
      the second meal effect from food and beverage intake of the night before each study visit.

      Subjects will arrive at the center after ~10 hours overnight fasting, well hydrated and
      rested. Each study visit will require blood draws throughout the visit. After pre-study
      procedures (height, weight, waist circumferences, vital sign, and fasting blood glucose
      test), a registered nurse will place a catheter in subject's arm for the purpose of multiple
      blood sample collections and collect fasting blood sample. During each study visit, subject
      will take one of the two capsules right after fasting blood draw), based on randomization
      sequences (either 1 grape seed extract capsule or 1 placebo capsule). One hour after
      administration of the assigned capsule, blood samples will be collected. And a standard high
      carbohydrate and high fat breakfast meal will be served and subject will have blood draws at
      designated time up to 5 hours.
    

Intervention name(s): Active Capsule; Placebo Capsule
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): GSE Capsule; Placebo Capsule
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Other
Keywords: Grape seed extract; Polyphenols; Insulin; Oxidative stress Marker; Inflammatory marker; Healthy human