Low-dose supplementation with lycopene or β-carotene does not enhance cell-mediated immunity in healthy free-living elderly humans

Objective: To assess the effects of supplementation with the carotenoids, beta -carotene or lycopene, at levels achievable within a diet rich in fruit and vegetables, on immune function in a group of free-living healthy elderly. Design: A double-blind randomized placebo-control led trial. T cell subsets and the expression of functionally associated cell surface molecules, quantified by flow cytometry, and lectin-stimulated lymphocyte proliferation, were compared before and following the treatment period. Subjects: Fifty-eight subjects aged over 65 y were recruited; 52 were included in the final analysis. Interventions: Participants received one placebo, one lycopene (13.3 mg) or one beta -carotene (8.2 mg) capsule daily for 12 weeks. Results: No significant differences were observed in any of the parameters examined following either lycopene or beta -carotene supplementation. Conclusions: In well-nourished, free-living, healthy elderly individuals, supplementation with relatively low levels of beta -carotene or lycopene is not associated with either a beneficial or detrimental effects on several aspects of cell-mediated immunity. Sponsorship: Financial support was provided by the Commission of the European Communities, specific programme AIR2 CT93-0888 DGXII SSMA, 'Increased fruit and vegetable consumption within the EC: potential health benefits', co-ordinated by Professor S Southon, Institute of Food Research, Norwich, UK.