A diet high in carotenoid-rich vegetables and fruits favorably impacts inflammation status by increasing plasma concentrations of IFN-α2 and decreasing MIP-1β and TNF-α in healthy individuals during a controlled feeding trial

The health benefits of vegetable and fruit (VF) intake include benefits for diseases that have an inflammatory component, although the relationship between VF intake and systemic inflammatory status is unclear due to the lack of comprehensive analysis of inflammatory markers in most studies. Therefore, our hypothesis was that the consumption of carotenoid-rich vegetables and fruits in the diet would have a beneficial effect on systemic inflammation status. In this study, we determined the association between varying doses of carotenoid-rich VF intake, plasma carotenoids, and a broad array of markers including 26 cytokines and high-sensitivity C-reactive protein. Data were derived from a single-arm controlled clinical feeding trial in which healthy, nonobese individuals received a low-carotenoid prescription for 6 weeks and then consumed a provided high-VF diet for 8 weeks. Proinflammatory cytokines and plasma carotenoids were measured at baseline, at 6 weeks, and at the end of the 8-week feeding period. Maximum likelihood estimation was used to calculate overall correlations between total plasma carotenoid concentrations and the cytokines. Plasma carotenoids decreased during the low-carotenoid treatment and increased during the feeding treatment. Of the inflammatory markers measured, we found increased plasma concentrations of interferon α-2 (P = .003) and decreased macrophage inflammatory protein-1β (P = .027) and tumor necrosis factor-α (P = .012) after consumption of the carotenoid-rich diet. These results indicate that consumption of VF may be important in the maintenance of beneficial inflammatory homeostasis.