Watercress supplementation in diet reduces lymphocyte DNA damage and alters blood antioxidant status in healthy adults.
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.
Gill
Chris I R
CI
Northern Ireland Centre for Food and Health, Centre for Molecular Biosciences, University of Ulster, Coleraine, N Ireland, United Kingdom. c.gill@ulster.ac.uk
Haldar
Sumanto
S
Boyd
Lindsay A
LA
Bennett
Richard
R
Whiteford
Joy
J
Butler
Michelle
M
Pearson
Jenny R
JR
Bradbury
Ian
I
Rowland
Ian R
IR
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
D000975:Antioxidants