Curcumin and Retinal Study

January 12, 2026 updated by: Texas Tech University Health Sciences Center

Curcumin and Retinal Amyloid-beta Pilot Study

To test how two weeks of curcumin supplementation would cross the blood brain barrier (BBB) and attach to amyloid beta proteins, to assess the feasibility (safety and bioavailability), and to explore the resulting abundance/composition of gut microbiota.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Alzheimer's disease (AD) leads to progressive cognitive decline. Increased amyloid beta (Aβ) burden and Aβ deposits have been shown in the AD retina. Aβ accumulation inside retinal pericytes in AD and pericyte degeneration in the retina mirror prominent features of brain AD pathology. Curcumin, a derivative of turmeric, has a high affinity for amyloid beta. Thus, curcumin would bind to amyloid beta plaques and emit a strong fluorescent signal, suggesting it can be a powerful diagnostic tool for AD. Emerging evidence has shown the connection between the brain and GI tract (gut microbiome), and its potential implications for both metabolic and neurologic diseases including AD. This pilot study is to test how two weeks of curcumin supplementation would cross the blood brain barrier and attach to amyloid beta proteins and to explore the resulting abundance/composition of gut microbiota. The investigators plan to recruit subjects through direct person-to-person solicitation in the Ophthalmology clinics, health fairs, community events, flyers, non-solicited email system, campus announcements, Clinical Research Institute Volunteer Database website, local radio, newspapers, senior newsletters, and TV scripts. The Clinical Research Institute Volunteer database will also be queried and potential subjects contacted as requested in their form. The investigators plan to enroll approximately 100-150 patients to obtain 30-40 qualified subjects at the start of the study. After screening, qualified participants will be randomly assigned to a low curcumin group or high curcumin group. Thus, this pilot study would focus on characterizing the distribution, manifestation, and prevalence of curcumin-loaded retinal Aβ deposits in study subjects with existing Aβ plaque (primary outcome). In addition, this study will assess safety, bioavailability, and fecal microbiome composition (secondary outcome). All outcomes will be assessed at baseline and after 2 weeks of intervention. Data will be analyzed statistically.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
60

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Texas
      • Lubbock, Texas, United States, 79430
        • Recruiting
        • Texas Tech University Health Sciences Center
        • Contact:
        • Principal Investigator:
          • Chwan-Li (Leslie) Shen, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

40 years to 89 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion:

  • Both male and female, age 40 - 89 years.
  • Diagnosed with Aβ deposits in retina (peripheral superior quadrants)--to be confirmed after consent obtained. If there is documentation the potential participant has been diagnosed with Aβ deposits in retina within 6 months before the consent session, we will use this diagnosis/documentation for eligibility criteria. Otherwise, the ophthalmic exam will be repeated after consent is obtained for the study.
  • No pre-existing liver or kidney diseases by self-report.

Exclusion:

  • Patients with ocular diseases (macular degeneration, severe diabetes retinopathy)
  • Had used systemic antibiotics within 1 month prior to the start of the study intervention
  • Had taken any turmeric or curcumin products within 2 weeks prior to the start of the study intervention
  • Had a known allergy to black pepper
  • Women that are pregnant or breastfeeding

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Low curcumin group
Drug: Low curcumin group
One curcumin capsule (250 mg curcumin) after each meal, 3 times a day for 2 weeks.
Active Comparator: High curcumin group
Drug: High curcumin group
One curcumin capsule (500 mg curcumin) after each meal, 3 times a day for 2 weeks.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Retinal imaging- amyloid fluorescent intensity
Time Frame: Baseline
To access amyloid fluorescent intensity
Baseline
Retinal imaging-amyloid fluorescent deposit number
Time Frame: Baseline
To access amyloid fluorescent deposit number
Baseline
Retinal imaging-amyloid fluorescent location
Time Frame: Baseline
To access amyloid fluorescent location
Baseline
Retinal imaging-amyloid fluorescent intensity
Time Frame: After 2 weeks
To access amyloid fluorescent intensity
After 2 weeks
Retinal imaging-amyloid fluorescent deposit number
Time Frame: After 2 weeks
To access amyloid fluorescent deposit number
After 2 weeks
Retinal imaging-amyloid fluorescent location
Time Frame: After 2 weeks
To access amyloid fluorescent location
After 2 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Bioavailability- curcumin concentrations in plasma
Time Frame: Baseline
To measure curcumin concentrations in plasma
Baseline
Bioavailability-curcumin concentrations in red blood cells
Time Frame: Baseline
To measure curcumin concentrations in red blood cells
Baseline
Bioavailability-curcumin concentrations in plasma
Time Frame: After 2 weeks
To measure curcumin concentrations in plasma
After 2 weeks
Bioavailability-curcumin concentrations in red blood cells
Time Frame: After 2 weeks
To measure curcumin concentrations in red blood cells
After 2 weeks
Liver function-serum AST
Time Frame: Baseline
To assess serum AST
Baseline
Liver function-serum ALT
Time Frame: Baseline
To assess serum ALT
Baseline
Kidney function-serum BUN
Time Frame: Baseline
To assess serum BUN
Baseline
Liver function-serum ALT
Time Frame: After 2 weeks
To assess serum ALT
After 2 weeks
Kidney function-serum BUN
Time Frame: After 2 weeks
To assess serum BUN
After 2 weeks
Gut microbiome-abundance
Time Frame: Baseline
To measure the abundance of intestinal bacterial in feces
Baseline
Gut microbiome-composition
Time Frame: Baseline
To measure the composition of intestinal bacterial in feces
Baseline
Gut microbiome-abundance
Time Frame: After 2 weeks
To measure the abundance of intestinal bacterial in feces
After 2 weeks
Gut microbiome-composition
Time Frame: After 2 weeks
To measure the composition of intestinal bacterial in feces
After 2 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Texas Tech University Health Sciences Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Chwan-Li (Leslie) Shen, PhD, Texas Tech University Health Sciences Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 21, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 23, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 15, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 20, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 13, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 12, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Curcumin-Retinal Pilot Study

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

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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