Proanthocyanins (PAs), also known as condensed tannins, are like flavonoids in that they give flowers and frutis a purple, red, or blue color. they are very powerful antioxidants and free-radical scavengers.
Use
They increase the circulation health of the heart, hands, feet, and other areas of the body. According to Dr. Ray Sahelian, "Evidence suggesting that dietary polyphenols, flavanols, and proanthocyanidins in particular offer significant cardiovascular health benefits is rapidly increasing. Proanthocyanidin-rich grape seed extract has preventive actions on diseases such as atherosclerosis, gastric ulcer, large bowel cancer, cataracts and diabetes."
Plants
Apples, grapes (seeds and skins), unsweetened baking chocolate, red wines, cranberries, blueberries, pecans, pistachios, hazelnuts, and chokeberries.
Personal Experience
I don't know much about Proanthocyanins. I'll post more as I learn about them.