Dietary polyphenols are naturally occurring compounds found largely in fruits, vegetables, cereals and beverages. Fruits like grapes, apple, pear, cherries and berries contains up to 200–300 mg polyphenols per 100 grams fresh weight. The products manufactured from these fruits, also contain polyphenols in significant amounts. Typically a glass of red wine or a cup of tea or coffee contains about 100 mg polyphenols. (Oxid Med Cell Longev. 2009)
Kesavan, P., et al., Chapter 17 – An Overview of Dietary Polyphenols and Their Therapeutic Effects, in Polyphenols: Mechanisms of Action in Human Health and Disease (Second Edition), R.R. Watson, V.R. Preedy, and S. Zibadi, Editors. 2018, Academic Press. p. 221-235.