A compound (containing more than one phenolic hydroxyl group) that acts as an antioxidant in your body. Polyphenols are a key component to olive oil, and are considered to be one of the best health benefits in the oil. Polyphenols furnish the immune system, protect us from heart diseases and display anticancer activity as they act as free radicals traps. They protect olive oil from oxidative damage and they contribute to its superior oxidative stability. They also can affect its taste, giving it a distinctive bitter flavor.