title: Worldwide (poly)phenol intake: assessment methods and identified gaps.
abstract: BACKGROUND
  (Poly)phenols (PPs) are plant secondary metabolites widely distributed in dietary sources, and several evidences show that consumption of PP has a positive impact in human health. However, the correct estimation of food intake and the estimation of PP content of foods are essential to associate PPs intake with health effects.
  
  
  OBJECTIVE
  This review aimed to gather information from several studies on PP intake in different countries, compare methods used for both assessment of food intake and PP quantification and highlight existing gaps and future directions.
  
  
  METHODS
  Twenty-four studies of PP intake from thirteen countries were selected for analysis. The selected studies included assessment of all plant food groups contributing to PP intake, total PP content and/or content of major classes (flavonoids or phenolic acids), a large study population and both genders.
  
  
  CONCLUSIONS
  Most studies presented daily intakes of extractable (poly)phenols. Very few studies have determined intake of non-extractable (poly)phenols, which is a very important fraction of PPs contributing to total PP intake. High heterogeneity was observed among countries regarding the intake of total PP intake and the two main PP classes. This may reflect not only different diet patterns, but also different methods used for collecting food consumption data and estimation of PP content. Thus, criteria of harmonization are suggested regarding assessment of food intake, determination of PP content in foods and validation with biomarkers.
authors.affiliation: Escola Superior Agrária, Instituto Politécnico de Santarém, Qta do Galinheiro, 2001-904, Santarém, Portugal.|Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2781-157, Oeiras, Portugal.|iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal.
authors.forename: Paula
authors.initials: P
authors.lastname: Pinto
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2781-157, Oeiras, Portugal. csantos@itqb.unl.pt.|iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal. csantos@itqb.unl.pt.
authors.forename: Cláudia N
authors.initials: CN
authors.lastname: Santos
mesh_terms: D015415:Biomarkers / Q000097:blood; D004032:Diet; D002523:Edible Grain / Q000737:chemistry; D007887:Fabaceae / Q000737:chemistry; D005504:Food Analysis; D005638:Fruit / Q000737:chemistry; D006801:Humans; D015596:Nutrition Assessment; D009753:Nutritive Value; D064209:Phytochemicals / Q000008:administration & dosage / Q000032:analysis; D059808:Polyphenols / Q000008:administration & dosage* / Q000097:blood*; D014675:Vegetables / Q000737:chemistry
chemical_list: D015415:Biomarkers; D064209:Phytochemicals; D059808:Polyphenols
keywords: Biomarkers; Diet; Flavonoids; Food intake; Non-extractable polyphenols; Phenolic acids