Resveratrol to Enhance Vitality and Vigor in Elders

Inclusion Criteria: * Ability to understand study procedures and to comply with them for the entire length of the study; * Age 65 years and older; * Moderate to high functioning (i.e. a summary score of 4 - 10 on the Short Physical Performance Battery \[SPPB\]); * Body Mass Index (BMI) range: 20-39.9 kg/m2; * Willingness to undergo all testing procedures. Exclusion Criteria: * Failure to provide informed consent; * Allergy/sensitivity to grapes or Japanese knotweed; * Current dietary supplementation of grape seed extract or ginko biloba; * Consumption of ≥ 8 oz. of red wine/dealcoholized red wine/red or purple grape juice more than once weekly; * Consumption of any dietary supplements containing resveratrol, quercetin, or P. cuspidatum in the previous 90 days; * Active treatment for cancer, stroke (\< 6 months), peripheral vascular disease, coronary artery disease, myocardial infarction (\< 6 months), congestive heart failure (stage III or IV), valvular heart disease, major psychiatric disease, severe anemia (blood levels of Hemoglobin \< 8 g/dl), liver or renal disease, diabetes, severe osteoarthritis, blindness or deafness, fracture in upper or lower extremity ( \< 6 months), upper or lower extremity amputation, or Parkinson's disease; * Cognitive impairment (i.e. Mini Mental Status Exam ≤ 23); * History of significant head injury; * Physical activity (i.e. running, bicycling, etc.) ≥ 120 min/week; * Excessive alcohol use (\> 2 drinks/day) or alcohol abuse (\> 5 drinks/d…