Abstract
- Background
Age-related macular degeneration (AMD) represents the third leading global cause of irreversible blindness and visual impairment worldwide. Macular pigment optical density (MPOD) serves as a primary, non-invasive clinical biomarker for assessing retinal health and individual risk for AMD. The macular xanthophyll carotenoids—specifically lutein (L) and zeaxanthin (Z)—concentrate within the human retina to act as natural optical filters protecting underlying photoreceptors from phototoxic blue light, alongside providing vital antioxidant defense mechanisms. This randomized controlled study was designed to examine the physiological and optical effects of zeaxanthin-rich goji berry consumption on MPOD and skin carotenoid accumulation in a healthy middle-aged human population.
- Methods
A randomized, unmasked, parallel-arm clinical study was conducted involving 27 healthy human participants aged 45 to 65 years. Subjects were randomly assigned to consume either 28 grams of whole goji berries or a matched control supplement containing 6 mg of lutein and 4 mg of zeaxanthin (LZ) administered five times weekly over a continuous 90-day intervention period. Objective measurements of macular pigment optical density (MPOD) were evaluated at baseline and post-intervention across varying retinal eccentricities (0.25 and 1.75 degrees), while skin carotenoid scores were concurrently tracked at day 45 and day 90 to quantify systemic carotenoid bioavailability.
- Results
Following the 90-day intervention, participants in the goji berry group demonstrated a statistically significant increase in macular pigment optical density (MPOD) at both the 0.25 ($P = 0.029$) and 1.75 ($P = 0.044$) retinal eccentricities, whereas no significant changes in MPOD were observed in the lutein-zeaxanthin supplement group. Furthermore, skin carotenoid levels exhibited a statistically significant elevation in the goji berry cohort at day 45 ($P = 0.025$) and day 90 ($P = 0.006$), with no corresponding increases noted in the control group. The whole-food goji berry intervention was well-tolerated, demonstrating high participant adherence throughout the trial duration.
- Conclusions
Regular dietary intake of goji berries in a healthy middle-aged population significantly increases macular pigment optical density and elevates skin carotenoid levels. These clinical findings indicate that incorporating zeaxanthin-rich goji berries into the diet serves as an effective, accessible nutritional countermeasure that may help prevent or delay the onset and development of age-related macular degeneration.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8708314/