Watercress supplementation in diet reduces lymphocyte DNA damage and alters blood antioxidant status in healthy adults
Chris IR Gill, Sumanto Haldar, Lindsay A Boyd, Richard Bennett, Joy Whiteford, Michelle Butler, Jenny R Pearson, Ian Bradbury and Ian R Rowland 1 From the Northern Ireland Centre for Food and Health, Centre for Molecular Biosciences, University of Ulster, Coleraine, N Ireland, United Kingdom (CIRG, SH, LAB, JW, MB, JRP, IB, and IRR), and the Institute of Food Research, Norwich Research Park, Colney, Norwich, United Kingdom (RB)
Atstract 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.
Design: 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 fed85 g raw watercress daily for 8 wk in addition to their habitual diet. The effect of supplementation was measured on a rangeof 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, -tocopherol, lutein, and ß-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 controlphase) was associated with reductions in basal DNA damage (by17%; P = 0.03), in basal plus oxidative purine DNA damage (by23.9%; P = 0.002), and in basal DNA damage in response to exvivo hydrogen peroxide challenge (by 9.4%; P = 0.07). Beneficialchanges seen after watercress intervention were greater and more significant in smokers than in nonsmokers. Plasma luteinand ß-carotene increased significantly by 100% and33% (P < 0.001), respectively, after watercress supplementation.
Conclusion: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.