Effects of Goji vs. Fiber on Macular Degeneration

Age-related macular degeneration (AMD) is the third leading cause of blindness worldwide. The disease occurs when the macula in the central retina develops lesions due, in part, to the loss of the protection of macular pigments zeaxanthin, lutein, and meso-zeaxanthin, which are responsible for light filtering and oxidative defense. The major risk factor for AMD is aging, and currently, no definitive prevention for AMD exists.

Goji berry (Lycium Barbarum) is a fruit that has been used as traditional medicine in Asian countries for more than 2,000 years. Modern science has identified potential benefits of the berry in oxidant defense, immune regulation, diabetes, and vision in animal and cell models. Nonetheless, evidence regarding the effects of goji berries on human health is scarce. The bioactive components of goji berries include zeaxanthin, lutein, Lycium Barbarum polysaccharides-protein complex, betaine, cerebroside, minerals, and vitamins. Importantly, goji berries contain the highest concentration of zeaxanthin among all commonly consumed foods.

Previous clinical studies have shown that goji berries have a high bioavailability of zeaxanthin, and that macular pigment optical density (MPOD) was increased after supplementation. This study uses macular pigment optical volume (MPOV; a measure that integrates MPOD across multiple macular eccentricities) as the primary outcome measure. It is unknown if the changes in MPOV will be associated with other functional changes or anatomic conditions in the eye among a population with small drusen, a risk factor for AMD. In addition, the impact of goji berry intake on the gut microbiome profile and associated metabolites is unknown, and potentially important in understanding the mechanism(s) of action.

Participants who meet the eligibility criteria will be enrolled and will be randomized 1:1 to the goji berry arm or fiber arm of the study. Over the course of approximately 180 days, participants will consume the assigned food item five days per week and attend three study visits.

Study visits will include ophthalmic imaging and testing, skin carotenoid measurements, completion of a food record, height, weight, handgrip strength, blood pressure measurement, and fasting blood collection. At 2 timepoints participants will be asked to provide a stool sample (collected within 24 hours of visit).

• Stool microbiome [Срок оценки: Day 0 and Day 180]
• Spectral Domain-Ocular Coherence Tomography (SD-OCT) [Срок оценки: Day 0 and Day 180]
• Fundus autofluorescence (FAF) [Срок оценки: Day 0 and Day 180]
• Color Fundus Photography (CFP) [Срок оценки: Day 0 and Day 180]
• Microperimetry testing [Срок оценки: Day 0 and Day 180]
• Dark adaptometry [Срок оценки: Day 0 and Day 180]
• Plasma microbial metabolites [Срок оценки: Day 0 and Day 180]
• Plasma lutein and zeaxanthin [Срок оценки: Day 0 and Day 180]
• Lipoprotein profile [Срок оценки: Day 0 and Day 180]
• HDL particle characteristics [Срок оценки: Day 0 and Day 180]
• Peripheral blood mononuclear cells (PBMC) gene expression changes [Срок оценки: Day 0 and Day 180]
• Cognitive function [Срок оценки: Day 0 and Day 180]