Does tomato consumption effectively increase the resistance of lymphocyte DNA to oxidative damage?

Background: Lycopene, the main carotenoid in tomato, has been shown to be a potent antioxidant in vitro. However, there is no significant evidence of its antioxidant action in vivo. Objective: We evaluated the effect of tomato intake on plasma carotenoid co ncentrations and lymphocyte resistance to oxidative stress. Design: Ten healthy women (divided into 2 groups of 5 subjects each) ate a diet containing tomato puree (providing 16.5 mg lycopene) and a tomato-free diet for 21 d each in a crossover design. Before and after each diet perio d, plasma carotenoid concentrations and primary lymphocyte resistance to ox idative stress (evaluated by means of single-cell gel electrophoresis) were analyzed. Results: After the first 21-d experimental period, total plasma lycopene co ncentrations increased by 0.5 mu mol/L (95% CI: 0.14, 0.87) in the group th at consumed the tomato diet and decreased by 0.2 mu mol/L. (95% CI: -0.11, -0.30) in the group that consumed the tomato-free diet (P < 0.001). Tomato consumption also had an effect on cellular antioxidant capacity: lymphocyte DNA damage after ex vivo treatment with hydrogen peroxide decreased by 33% (95% CI: 0.8%, 61%; P < 0.05) and by 42% (95% CI: 5.1%, 78%; P < 0.05)in t he 2 groups of subjects after consumption of the tomato diet. Conclusion: The consumption of tomato products may reduce the susceptibilit y of lymphocyte DNA to oxidative damage.