Effects of Goji vs. Fiber on Macular Degeneration (GOJI)

Effects of Goji Berry Intake on Risk of Age-related Macular Degeneration: A Randomized Clinical Trial

The goal of this project is to conduct a clinical trial in 60 participants ranging from age 65-95 who are at risk for age-related macular degeneration (AMD). The study will evaluate the effects of 14g of goji berry intake or an equivalent amount and type of fiber, five days a week for six months, on visual health, gut microbiome profiles, skin carotenoid measures, and lipoprotein profiles.

Study Overview

• Status: Recruiting
• Conditions: Age-Related Macular Degeneration
• Intervention / Treatment: Dietary supplement: Fiber; Dietary supplement: Goji berry

Detailed Description

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).

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Denise Macias, CCRP; Phone Number: (916) 734-6303; Email: dcmacias@ucdavis.edu

Study Locations

• United States
  • California
    • Sacramento, California, United States, 95817
      • Recruiting
      • UC Davis Eye Center, Tschannen Eye Institute
      • Contact: Susan M Garcia; Phone Number: 916-734-4546; Email: smgarcia@ucdavis.edu
      • Contact: Denise C Macias; Phone Number: (916) 734 6303; Email: dcmacias@ucdavis.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Family history of AMD
• Hyperlipidemia or managed diabetes
• 65 - 95 years of age

Exclusion Criteria:

• Dislike of, or allergy to, goji berries or any of the ingredients in the fiber-rich wafers and gummies (wheat, corn, oats, soy, natural orange flavor, xylitol, annatto, pectin, or other food ingredients)
• Consumption of > 2 alcoholic drinks per day
• Indications of substance or alcohol abuse
• Current or planned use of a blood thinner (e.g., Coumadin, Warfarin) at any time during study
• Use of multi-vitamin or any other supplements that contain lutein and/or zeaxanthin (if willing to stop the supplement, subject can be enrolled 6 months from stop date)
• Taking any new medications started within the past 6 months, or changes in medication regimen planned in the next 6 months (stable use greater than 6 months is not exclusionary)
• Any planned international travel during the study
• Consuming >3 servings/day of a combination of spinach, kale, lettuce, orange bell peppers, corn, parsley, squash, broccoli, pumpkin, edamame
• Regularly consuming >3 eggs/day
• Currently participating in any other interventional research study
• Diagnosed with inflammatory bowel disease, irritable bowel syndrome, other gastrointestinal disorder, undergoing cancer therapy or immunocompromised, or diagnosis of another condition where lutein, zeaxanthin and/or fiber supplementation would be contraindicated or would interfere with ability to participate in the study
• Any physical characteristic or condition that precludes ability to perform study procedures
• Medical or psychiatric condition that, in the opinion of the Investigator, would compromise study findings or prevent the participant from completing the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Goji berry; For the goji berry arm, participants will consume goji berries.	Dietary supplement: Goji berry; Participants will be instructed to consume 14 grams of goji berries 5 days a week for 6 months
Active Comparator: Fiber; For the fiber arm, participants will consume fiber supplements that closely matches the fiber type and amount found in the portion of goji berries.	Dietary supplement: Fiber; Participants will be instructed to consume the fiber supplements 5 days a week for 6 months

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Macular pigment optical volume (MPOV)	MPOV provides an objective measure of macular pigments by using dual wavelength autofluorescence using the Heidelberg Spectralis to obtain HRA + OCT measures	Day 0 and Day 180

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Color Fundus Photography (CFP)	CFP imaging uses a standard retinal camera.	Day 0 and Day 180
Dark adaptometry	Dark adaptometry will be assessed using a standard protocol.	Day 0 and Day 180
Plasma microbial metabolites	Biogenic amines will be measures by LC-MS	Day 0 and Day 180
HDL particle characteristics	Plasma will also be used to isolate and characterize HDL particles.	Day 0 and Day 180
Stool microbiome	Metagenomic sequencing	Day 0 and Day 180
Spectral Domain-Ocular Coherence Tomography (SD-OCT)	Central subfield thickness will be measured using the OCT instrument's algorithm	Day 0 and Day 180
Fundus autofluorescence (FAF)	Blue FAF imaging will be performed to assess variations in lipofuscin autofluorescence	Day 0 and Day 180
Microperimetry testing	Microperimetry will be tested according to a standard protocol using a Nidek MP-1 instrument	Day 0 and Day 180
Plasma lutein and zeaxanthin	Plasma concentrations of lutein and zeaxanthin will be measured by LC-MS	Day 0 and Day 180
Lipoprotein profile	Lipoprotein profiles will be measured according to standard protocols	Day 0 and Day 180
Peripheral blood mononuclear cells (PBMC) gene expression changes	PBMCs will be collected to monitor gene expression changes.	Day 0 and Day 180
Cognitive function	Cognitive function will be assessed using web-based CANTAB tests	Day 0 and Day 180
Handgrip strength	Handgrip strength will be measured using a Jamar hand dynamometer	Day 0 and Day 180

Collaborators and Investigators

• Sponsor: University of California, Davis
• Collaborators: United States Department of Agriculture (USDA)
• Investigators: Principal Investigator: Robert M Hackman, PhD, University of California, Davis; Principal Investigator: Glenn Yiu, MD, PhD, University of California, Davis; Principal Investigator: Angela M Zivkovic, PhD, University of California, Davis

Study record dates

Study Major Dates

• Study Start (Actual): April 29, 2024
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: January 19, 2024
• First Submitted That Met QC Criteria: January 24, 2024
• First Posted (Actual): February 1, 2024

Study Record Updates

• Last Update Posted (Actual): June 24, 2025
• Last Update Submitted That Met QC Criteria: June 17, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Fiber; HDL; Age-Related Macular Degeneration; Carotenoids; Gut Microbiome; Lutein; Zeaxanthin; Eye Health; Goji Berry; Cholesterol Efflux Capacity
• Additional Relevant MeSH Terms: Eye Diseases; Retinal Diseases; Retinal Degeneration; Macular Degeneration
• Other Study ID Numbers: 2082960

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No