Considerable information on polyphenol content in foods is scattered in up to 1000 peer-reviewed publications and is therefore not easily exploited. Over 60000 food composition data have been collected from this literature and stored in the new Phenol-Explorer database ( www.phenol-explorer.eu ). Thirty-seven thousand data were selected after evaluation and aggregated separately according to 5 categories of analytical methods to generate mean content values for 502 compounds (glycosides, esters, or aglycones) in 452 foods. These data are exploited here in a first systematic analysis of the content in foods of these 502 polyphenols. These data will be useful for epidemiologists to determine polyphenol intake and associations with health and diseases in populations and for food scientitsts and food manufacturers to develop new products with optimized properties.