Effects of Long-Term Supplementation with Centella asiatica (L.) Urb. Extract (CA-HE50) on Macular Pigment Optical Density: A Randomized, Double-Blind, Placebo-Controlled Trial

Background/Objectives: Macular pigment optical density (MPOD) is a nutrition-responsive biomarker that indicates the antioxidant status of the macula. This study aimed to evaluate the effects of long-term supplementation with a standardized Centella asiatica (L.) Urb. extract (CA-HE50) on MPOD in a randomized, double-blind, placebo-controlled clinical trial. Methods: Eighty men and women aged 45–65 years, with baseline MPOD values between 0.2 and 0.4, were randomly assigned to receive either CA-HE50 (300 mg/day, n = 40) or a placebo (n = 40) for 6 months. Efficacy was assessed by measuring MPOD at baseline and on Days 60, 120, and 180. The primary efficacy endpoint was the change in MPOD from baseline to Day 180. Safety was evaluated through monitoring adverse events, vital signs, and clinical laboratory tests. Results: By Day 180, supplementation with CA-HE50 resulted in a statistically significant increase in MPOD compared to the placebo in the right eye, left eye, and the average of both eyes (all p < 0.001). Significant between-group differences were also observed at Day 120, indicating a time-dependent improvement in MPOD. Additionally, the proportion of responders was significantly higher in the CA-HE50 group compared to the placebo group (p < 0.001). CA-HE50 was well tolerated, with no serious adverse events or clinically relevant safety concerns identified during the intervention period. Conclusions: Long-term supplementation with C. asiatica extract significantly improved MPOD, supporting its potential role in enhancing macular nutritional status. These findings suggest that CA-HE50 may serve as a beneficial dietary intervention for maintaining macular health.