Mining the polyphenol metabolome to identify in population studies its components most protective against chronic diseases

Much evidence supports the role of dietary polyphenols in the prevention of chronic diseases. However polyphenols are not all equal. Their bioavailability and biological properties differ widely according to their fine chemical structures, and the exact nature of the most protective compounds is still largely unknown. Past epidemiological studies have largely been focused on a limited number of phenolic compounds. No detailed and comprehensive view on associations between exposure to polyphenols and health is so far available and new tools are needed to develop Metabolome-Wide Association Studies (MWAS) on polyphenols and to identify individual phenolic compounds most strongly associated to disease risk.

Based on a systematic literature search, we have built the open access Phenol-Explorer database (http://www.phenol-explorer.eu/) that includes more than 36,000 composition data for 502 polyphenols in 452 foods ^{1, 2} . The quality of the data was assessed. Data of sufficient quality was integrated in the Phenol-Explorer database. This data has been used to build food composition tables for polyphenols and to generate the most comprehensive data on polyphenol intake in the French SU.VI.MAX cohort ³ and the European Prospective Investigation on Cancer and Nutrition (EPIC) study et to evaluate associations with functional outcomes and disease risk. Further data on the effects of food processing and cooking on polyphenol content are now being collected from over 200 original publications to further improve accuracy of food composition tables. Retention factors for a large number of polyphenols in various foods will soon be made available to the public.

The use of urinary or blood biomarkers may offer a more objective way to assess personal exposure to dietary polyphenols in population studies ⁴ . In order to help in the identification of the most appropriate polyphenol biomarkers, we collected data from over 200 peer-reviewed publications on 375 plasma and urinary metabolites described in both human and animal experimental. This information available on the Phenol-Explorer website is now exploited to identify polyphenol metabolites in metabolic fingerprints from population studies.

This work on dietary polyphenols emphasizes the importance of data biocuration to better understand the role of plant/food bioactives in human health and diseases ⁵ . It could be extended to other families of plant/food constituents in a larger community effort.

References

(1) Perez-Jimenez, J.; Neveu, V.; Vos, F.; Scalbert, A. Systematic analysis of the content of 502 polyphenols in 452 foods and beverages: An application of the Phenol-Explorer database. J. Agric. Food Chem. 2010, 58, 4959–4969.

(2) Perez-Jimenez, J.; Neveu, V.; Vos, F.; Scalbert, A. Identification of the 100 richest dietary sources of polyphenols – An application of the Phenol-Explorer database. Eur. J. Clin. Nutr. 2010, 64, S112-S120.

(3) Perez-Jimenez, J.; Fezeu, L.; Touvier, M.; Arnault, N.; Manach, C.; Hercberg, S.; Galan, P.; Scalbert, A. Dietary intake of 337 polyphenols in French adults. Am. J. Clin. Nutr. 2011, 93, 1220–1228.

(4) Perez-Jimenez, J.; Hubert, J.; Ashton, K.; Hooper, L.; Cassidy, A.; Manach, C.; Williamson, G.; Scalbert, A. Urinary metabolites as biomarkers of polyphenol intake in humans – A systematic review. Am. J. Clin. Nutr. 2010, 92, 801–9.

(5) Scalbert, A.; Andres-Lacueva, C.; Arita, M.; Kroon, P.; Manach, C.; Urpi-Sarda, M.; Wishart, D. Databases on food phytochemicals and their health promoting effects. J. Agric. Food Chem. 2011, 59, 4331–48.