Grape Polyphenol Kinetics in Humans

16 oz. of Concord grape juice (8 oz. consumed 2 times per day; total dose of approximately 1.2 g phenolic compounds per day), 250 mg resveratrol provided as a capsule (commercially available supplement; 125 mg consumed 2 times per day), and 1 g grape seed polyphenol extract provided as a capsule (commercially available supplement; 0.5 g consumed 2 times per day).