title: Impact of Natural Juice Consumption on Plasma Antioxidant Status: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  Oxidative stress may lead to overproduction of reactive species and a decrease in antioxidant defenses, resulting in chronic diseases such as diabetes and cancer. The consumption of natural compounds with an antioxidant profile may be a preventive alternative. Therefore, we aimed to obtain evidence regarding the potential antioxidant activity of juices in human plasma.
  
  
  METHODS
  A systematic review and meta-analysis was performed, which included randomized controlled trials that compared the use of fruit or vegetable juices vs. placebo or other beverages. An electronic search was conducted in PubMed, Scopus, International Pharmaceutical Abstracts, and SciELO. The outcome measures extracted were related to antioxidant status, e.g., vitamin C, superoxide dismutase (SOD), and catalase (CAT) levels and reduction in malondialdehyde (MDA) and antioxidant capacity measured as TEAC.
  
  
  RESULTS
  Twenty-eight trials were identified (n = 1089), of which 16 were used for meta-analysis. No significant differences were observed between juices and placebo with regard to TEAC, SOD, and CAT. However, juices were superior to control in enhancing vitamin C and reducing MDA.
  
  
  CONCLUSIONS
  Natural juices are possible candidates for the management of oxidative stress. The effects of juices should be further investigated by conducting larger and well-defined trials of longer duration.
authors.affiliation: Department of Pharmacy, Pharmaceutical Sciences Postgraduate Program, Universidade Federal do Paraná, Av. Prof. Lothario Meissner 632, 80210-170 Curitiba, Brazil. fer_stumpf_tonin@hotmail.com.
authors.forename: Fernanda S
authors.initials: FS
authors.lastname: Tonin
authors.affiliation: Department of Pharmacy, Pharmaceutical Sciences Postgraduate Program, Universidade Federal do Paraná, Av. Prof. Lothario Meissner 632, 80210-170 Curitiba, Brazil. laizasteimbach@gmail.com.
authors.forename: Laiza M
authors.initials: LM
authors.lastname: Steimbach
authors.affiliation: Department of Pharmacy, Pharmaceutical Sciences Postgraduate Program, Universidade Federal do Paraná, Av. Prof. Lothario Meissner 632, 80210-170 Curitiba, Brazil. astridwiens@hotmail.com.
authors.forename: Astrid
authors.initials: A
authors.lastname: Wiens
authors.affiliation: Department of Pharmacy, Postgraduate Program in Pharmaceutical Care, Universidade Federal do Rio Grande do Sul, Av. Paulo Gama 110, 90040-060 Porto Alegre, Brazil. mperlin.cassio@gmail.com.
authors.forename: Cássio M
authors.initials: CM
authors.lastname: Perlin
authors.affiliation: Department of Pharmacy, Pharmaceutical Sciences Postgraduate Program, Universidade Federal do Paraná, Av. Prof. Lothario Meissner 632, 80210-170 Curitiba, Brazil. pontarolo@ufpr.br.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pontarolo
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D001205:Ascorbic Acid / Q000097:blood; D001628:Beverages; D002374:Catalase / Q000097:blood; D004435:Eating / Q000502:physiology; D005638:Fruit; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress / Q000187:drug effects; D016032:Randomized Controlled Trials as Topic; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D000975:Antioxidants; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid
keywords: antioxidant capacity; health benefits; juice; systematic review