Effect of Dietary Supplementation with Lutein, Zeaxanthin, and Elderberries on Dry Eye Disease (DED) and Immunity: A Randomized Controlled Trial

Abstract

Background/Objectives: Dry eye disease (DED) significantly impairs quality of life, affecting physical, social, and psychological well-being, as well as reducing workplace productivity. While lutein and zeaxanthin supplements have been shown to improve ocular health, existing research often overlooks the efficacy of lower dosages and shorter durations of supplementation. This study investigated the effects of combined supplementation with lutein, zeaxanthin, and elderberries in 110 voluntary participants through a randomized controlled trial. Methods: Participants took 6 mg of lutein and 1 mg of zeaxanthin, along with 100 mg elderberry extract once daily for a duration of 20 days. Ocular health was assessed using the Ocular Surface Disease Index (OSDI), while immune status was evaluated with the Immune Status Questionnaire (ISQ). Results: Results showed that combined supplementation significantly (p < 0.05) reduced the OSDI scores in the intervention group from 38.15 ± 11.14 to 18.26 ± 5.57, reflecting a 52.2% reduction. A similar trend was observed with the Visual Analog Scale (VAS), indicating significant (p < 0.05) improvement from 5.31 ± 1.62 to 6.73 ± 1.74, equivalent to a 26.7% improvement. Although the intervention group showed a 15.9% improvement in ISQ scores by the study’s end, this was not significantly different from the placebo group, suggesting that higher dosages or longer durations may be needed to observe a meaningful effect. Additionally, findings from the Food Frequency Questionnaire revealed that the average dietary intake of lutein and zeaxanthin among participants was only 663.49 µg, equating to just 5.5% of the suggested optimal daily intake. This low consumption is concerning, as it is inversely correlated with the risk of ocular diseases. Conclusions: Collectively, these findings support the use of combined supplementation as an adjuvant approach to improving ocular health.