Lutein supplementation improves visual performance in Chinese drivers: 1-year randomized, double-blind, placebo-controlled study.

OBJECTIVES Although it is known that the carotenoid lutein can affect visual performance, we still have much to learn about its effect in occupational populations, like drivers. The aim of this study was to examine the effect of lutein supplementation on visual function in healthy drivers with long-term light exposure. METHODS The study was a randomized, double-blind, placebo-controlled, 1-y intervention study. It included 120 normal participants (drivers). The active (A) group consumed 20 mg of lutein daily. Participants were assessed at baseline, 1, 3, 6, and 12 mo (V0, V1, V2, V3, and V4, respectively). Assessment included visual acuity, serum lutein concentrations, macular pigment optical density (MPOD), and visual performance. At the onset and at the end of the intervention, dietary intakes of lutein and visual-related quality of life were measured. RESULTS There was a trend (in the active group) toward an increase in best spectacle-corrected visual acuity measured, but there were no significant differences. Serum lutein and central MPOD in the active group increased significantly, whereas no change was observed in the placebo group. We observed significant increases in contrast and glare sensitivity, especially in the mesopic condition. There were significant improvements in the score of the National Eye Institute 25-Item Visual Functioning Questionnaire driving subscale in the active group. CONCLUSIONS Daily supplementation with 20 mg of lutein increases MPOD levels. Lutein may benefit driving at night and other spatial discrimination tasks carried out under low illumination.