Since grapes, grape juice, red wine, and related nutraceutical supplements like Vindure 900 are all beneficial dietary supplements and foods, what about raisins?

Unfortunately, the answer is NO. Raisins, which of course are dried grapes, are not a good source of polyphenol nutrients. Exposure to light and oxidation that occurs in the air-drying process destroys Resveratrol and other polyphenols.