Acute Effects of Grape Seed Extract on Insulin Sensitivity and Oxidative Stress and Inflammation Markers.

Inclusion Criteria: * Aged between 20 to 65 years old * Body Mass Index (BMI) range from 18.5 to 24.9 kg/m2; exception BMI 18.5 to 23 kg/m2 for Asian population * Fasting blood glucose concentration \< 110 mg/dL * Fasting LDL-cholesterol \<180 mg/dL * Fasting Total cholesterol and Fasting Triglycerides \< 250 mg/dL * Weight stable: not gained or lost weight +/- 5 lbs in previous 3 months * Non-smokers * No clinical evidence of cardiovascular, metabolic, respiratory, renal, gastrointestinal or hepatic disease * Not taking any medications or dietary supplements that would interfere with outcomes of the study, i.e. lipid lowering medications, anti-inflammatory drugs, fish oil, probiotics, grape seed supplement, etc…If anti-inflammation and/or antibiotic medications/supplements are taken, subjects may qualify if go off these medications/supplements 30 days wash-out before entering the study. * Able to provide informed consent * Able to comply and perform the procedures requested by the protocol Exclusion Criteria: * Past smokers: abstinence for less than 2 years * Men and women who smoke * Men and women with known or suspected food intolerance, allergies or hypersensitivity to the study materials or closely related compound or any their stated ingredients. * Men and women known to have/diagnosed with diabetes mellitus * Men and women who have fasting blood glucose concentrations ≥110 mg/dL * Men and women who have uncontrolled blood pressure \>140 mmHg/90 mmHg * Men and women with documented vascular disease, e.g., heart failure, myocardial infarction, stroke, angina, related surgeries. * Men and women with cancer other than non-melanoma skin cancer in previous 5 years. * Men and women who are taking medication or dietary supplements that may interfere with the outcomes of the study; e.g., antioxidant supplements, anti-inflammation, lipid lowering medication. Subjects may choose to go off dietary supplements (requires 30 days washout). * Men and women who are taking blood pressure lowering medication that may interfere the outcomes of the study; e.g. diuretics. * Men and women who have donated blood within 3 months of the screening visit and blood donors/participants for whom participation in this study will result in having donated more than 1500 milliliters of blood in the previous 12 months. * Men and women who are vegetarians or vegans * Substance (alcohol or drug) abuse within the last 2 years. * Excessive coffee and tea consumers (\> 4 cups/day) * Men and women who do excessive exercise regularly or athlete * Unstable weight: gained or lost weight +/- 5 lbs in previous 3 months * Women who are known to be pregnant or who are intending to become pregnant over the course of the study * Women who are lactating