Lutein supplementation leads to decreased soluble complement membrane attack complex sC5b-9 plasma levels

Abstract

Purpose The purpose of this study was to investigate the effect of lutein on systemic complement activation in elderly individuals. Methods Seventy patients with signs of early age-related macular degeneration (AMD) were included in this study. All subjects were randomly assigned to receive a 10 mg daily dose of lutein or a placebo for a time period of 1 year. EDTA blood was collected before and at various time-points during the study (0, 4, 8 and 12 months). The plasma level of the soluble complement membrane attack complex sC5b-9 was measured by ELISA. Results We found a significant 1.1 ng/ml monthly decrease in the plasma sC5b-9 concentration in the lutein group (p < 0.001), resulting in a decrease from 60.3 ng/ml at baseline to 46.3 ng/ml at 12 months. For the placebo group, we found a significant 0.6 ng/ml monthly increase in plasma sC5b-9 concentration (p = 0.001), resulting in an increase from 51.6 ng/ml at baseline to 58.4 ng/ml at 12 months. Conclusions Lutein supplementation inhibits the systemic activation of the complement system, which provides further functional evidence for the reported beneficial effects of this carotenoid in the management of AMD.