title: Dietary phytochemical intake from foods and health outcomes: a systematic review protocol and preliminary scoping.
abstract: Dietary phytochemicals are found in plant-based foods such as fruits, vegetables and grains and may be categorised in a nested hierarchical manner with many hundred individual phytochemicals identified to date. To associate phytochemical intakes with positive health outcomes, a fundamental step is to accurately estimate the dietary phytochemical intake from foods reported. The purpose of this systematic review protocol is to describe the process to be undertaken to summarise the evidence for food-based dietary phytochemical intakes and health outcomes for adults.
  
  
  
  The review will be undertaken following the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions using the Review Manager software. Phytochemical subclasses (phenolic acids, flavanols, etc) will be used to search for relevant studies using the Web of Science and Scopus scientific databases. The retrieved studies will be screened based on inclusion of natural whole food items and health outcomes. Phytochemical studies related to cardiovascular disease, cancer, overweight, glucose tolerance, digestive, reproductive, macular and bone health and mental disorders, fatigue and immunity will be examined based on prior scoping. The evidence will be aggregated by the food types and health outcomes. Comparison of differences in the outcomes for randomised controlled trials and observational studies will be undertaken. The strength of the review lies in its focus on whole food items and health conditions rather than one type of phytochemical related to one single health condition. Subgroup and sensitivity analyses will be conducted where an adequate number of publications are found per phytochemical subclass.
  
  
  
  By comparing the outcomes from experimental and observational studies, the review will determine whether the overall conclusions related to the phytochemical subclasses are the same between study types for the identified health conditions. This is useful to public health policymakers and health professionals alike.
  
  
  
  #CRD42014015610.
authors.affiliation: Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia.|Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.
authors.forename: Yasmine C
authors.identifier: 0000-0002-1971-173X
authors.initials: YC
authors.lastname: Probst
authors.affiliation: Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia.|Illawarra Health and Medical Research Institute, Wollongong, New South Wales, Australia.
authors.forename: Vivienne X
authors.initials: VX
authors.lastname: Guan
authors.affiliation: Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia.|Faculty of Health, University of Tasmania, Tasmania, Australia.
authors.forename: Katherine
authors.initials: K
authors.lastname: Kent
mesh_terms: D001823:Body Composition; D001847:Bone Diseases; D002318:Cardiovascular Diseases; D004032:Diet; D005221:Fatigue; D005502:Food; D005767:Gastrointestinal Diseases; D006801:Humans; D007109:Immunity; D008603:Mental Health; D009369:Neoplasms; D050177:Overweight; D064209:Phytochemicals / Q000008:administration & dosage*; D060728:Reproductive Health; D012107:Research Design; D000078202:Systematic Reviews as Topic
chemical_list: D064209:Phytochemicals
keywords: NUTRITION & DIETETICS; Phytonutrient; Systematic review