Because polyphenols are present in plants, including fruits and vegetables, the sheer abundance of them means it’s relatively easy to get more in your diet – Plus, there are supplement forms as well.
To maximize the benefits of polyphenols, you must look at both the bioavailability and bioaccessibility of the polyphenols. Bioavailability refers to how many polyphenols are in a particular food. Bioaccessibility refers to how much of those polyphenols you are actually able to get/use from the food. Skins, seeds, barks and pits all contain some of the highest concentrations of polyphenols, but not edible parts of plants.