title: Watercress supplementation in diet reduces lymphocyte DNA damage and alters blood antioxidant status in healthy adults.
abstract: BACKGROUND
  Cruciferous vegetable (CV) consumption is associated with a reduced risk of several cancers in epidemiologic studies.
  
  
  OBJECTIVE
  The aim of this study was to determine the effects of watercress (a CV) supplementation on biomarkers related to cancer risk in healthy adults.
  
  
  METHODS
  A single-blind, randomized, crossover study was conducted in 30 men and 30 women (30 smokers and 30 nonsmokers) with a mean age of 33 y (range: 19-55 y). The subjects were fed 85 g raw watercress daily for 8 wk in addition to their habitual diet. The effect of supplementation was measured on a range of endpoints, including DNA damage in lymphocytes (with the comet assay), activity of detoxifying enzymes (glutathione peroxidase and superoxide dismutase) in erythrocytes, plasma antioxidants (retinol, ascorbic acid, alpha-tocopherol, lutein, and beta-carotene), plasma total antioxidant status with the use of the ferric reducing ability of plasma assay, and plasma lipid profile.
  
  
  RESULTS
  Watercress supplementation (active compared with control phase) was associated with reductions in basal DNA damage (by 17%; P = 0.03), in basal plus oxidative purine DNA damage (by 23.9%; P = 0.002), and in basal DNA damage in response to ex vivo hydrogen peroxide challenge (by 9.4%; P = 0.07). Beneficial changes seen after watercress intervention were greater and more significant in smokers than in nonsmokers. Plasma lutein and beta-carotene increased significantly by 100% and 33% (P < 0.001), respectively, after watercress supplementation.
  
  
  CONCLUSIONS
  The results support the theory that consumption of watercress can be linked to a reduced risk of cancer via decreased damage to DNA and possible modulation of antioxidant status by increasing carotenoid concentrations.
authors.affiliation: Northern Ireland Centre for Food and Health, Centre for Molecular Biosciences, University of Ulster, Coleraine, N Ireland, United Kingdom. c.gill@ulster.ac.uk
authors.forename: Chris I R
authors.initials: CI
authors.lastname: Gill
authors.forename: Sumanto
authors.initials: S
authors.lastname: Haldar
authors.forename: Lindsay A
authors.initials: LA
authors.lastname: Boyd
authors.forename: Richard
authors.initials: R
authors.lastname: Bennett
authors.forename: Joy
authors.initials: J
authors.lastname: Whiteford
authors.forename: Michelle
authors.initials: M
authors.lastname: Butler
authors.forename: Jenny R
authors.initials: JR
authors.lastname: Pearson
authors.forename: Ian
authors.initials: I
authors.lastname: Bradbury
authors.forename: Ian R
authors.initials: IR
authors.lastname: Rowland
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000032:analysis*; D018592:Cross-Over Studies; D004249:DNA Damage / Q000187:drug effects*; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D006262:Health; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D031223:Nasturtium
chemical_list: D000975:Antioxidants