Prolonged tomato juice consumption has no effect on cell-mediated immunity of well-nourished elderly men and women

Abstract

The immunomodulatory potential of carotenoids has been investigated thoroughly only for β-carotene. Data on the immunomodulatory activity of other carotenoids such as lycopene are scarce. The objective of this study was to investigate the effects of prolonged tomato juice consumption on cell- mediated immunity of well-nourished healthy elderly persons. In an intervention study, 33 female and 20 male subjects (aged 63-86 y) consumed 330 mL/d tomato juice (47.1 mg/d lycopene) or mineral water for 8 wk. Immune status was assessed by measuring number and lytic activity of natural killer (NK) cells, secretion of cytokines [interleukin (IL)-2, IL-4, tumor necrosis factor-α (TNF-α)] by activated peripheral blood mononuclear cells (PBMC), lymphocyte proliferation, and delayed-type hypersensitivity (DTH) skin responses. Tomato juice consumption resulted in significantly increased plasma lycopene and β-carotene concentrations over time. In both treatment groups, TNF-α and IL-4 secretion were increased at the end of the intervention period, whereas IL-2 secretion was decreased. Tomato juice consumption had no effect on lymphocyte proliferation, DTH or the number of NK cells. Lytic activity of NK cells was increased in both groups at the end of the intervention period. In conclusion, these results show that prolonged tomato juice consumption increased plasma lycopene concentrations without significantly affecting cell-mediated immunity in well-nourished elderly subjects.