Grape Polyphenol Kinetics in Humans

Inclusion Criteria: \- Exclusion Criteria: * Age \<60 years at beginning of study * Fasting glucose \> 126 mg/dl * Blood pressure \> 160/100 * Fasting total blood cholesterol \> 280 mg/dl * Fasting triglycerides \> 300 mg/dl * Presence of kidney disease, liver disease, gout, hyperthyroidism, untreated or unstable hypothyroidism, certain cancers, gastrointestinal disease, pancreatic disease, other metabolic diseases, or malabsorption syndromes * Presence of type 2 diabetes requiring the use of oral antidiabetic agents or insulin * History of bariatric or certain other surgeries related to weight control * Smokers or other tobacco users (during 6 months prior to the start of the study) * Consumption of more than 3 servings of tea, wine, or grape juice per day * Use of supplements containing grape extracts or products * Use of antibiotics during the intervention or for 3 weeks prior to the intervention period * History of eating disorders, dietary patterns, or supplement use which will interfere with the goal of the intervention * Volunteers who have lost 10% of body weight within the last 4 months * Volunteers who are unable or unwilling to give informed consent or communicate with study staff * Volunteers who self-report of alcohol or substance abuse within the past 12 months and/or current acute treatment or rehabilitation program for these problems (long-term participation in Alcoholics Anonymous is not an exclusion) * Other medical, psychiatric, or behavioral factors that in the judgment of the Principal Investigator may interfere with study participation or the ability to follow the intervention protocol