Cocoa, green tea, grape seed, olive oil, and apple may not taste good together, but they have one thing in common. All have been studied for their health benefits due to polyphenols that are extracted from them. Cocoa flavanols, green tea catechins, grape seed polyphenols, apple polyphenols, and olive hydroxytyrosol have been shown to benefit overall health, cardiovascular health, metabolism, and more. Here is a look at some of these polyphenol ingredients.