Yellow Potatoes and Carotenoids

June 9, 2026 updated by: University of Florida

Effects of Yellow Flesh Potatoes on Carotenoid Status

This study will assess the effects of daily intake of yellow and white potatoes on plasma lutein and zeaxanthin concentrations. Skin carotenoid levels will be assessed using the Veggie Meter.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Not Applicable

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

  • Name: Wendy J Dahl, PhD
  • Phone Number: 352-294-3707
  • Email: wdahl@ufl.edu

Study Locations

  • United States
    • Florida
      • Gainesville, Florida, United States, 32611
        • Recruiting
        • University of Florida
        • Contact:
          • Wendy Dahl, PhD
          • Phone Number: 352 294 3707
          • Email: wdahl@ufl.edu
        • Principal Investigator:
          • Wendy Dahl, PhD
        • Contact:

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adults ≥ 18 years of age
  • Able to provide written consent in English
  • Baseline Veggie Meter score of ≤ 300
  • Willing to adhere to study procedures

Exclusion Criteria:

  • Baseline Veggie Meter score of >300
  • Potato allergy
  • Previously or currently being treated for intestinal disease, including irritable bowel syndrome, Crohn's disease, ulcerative colitis, celiac disease, or gastrointestinal cancer
  • Previous gastrointestinal surgery (e.g., gastric bypass, fundoplication, bowel resection)
  • Current cancer treatment
  • Current pregnancy; Vegetarian diet
  • Elite athletes or long-distance runners

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: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Yellow-flesh potatoes
250 g of yellow-flesh potatoes
Other: Yellow-flesh potatoes
Participants will consume 250 g daily of yellow-flesh potatoes.
Placebo Comparator: White-flesh potatoes
250 g of white-flesh potatoes
Other: White-flesh potatoes
Participants will consume 250 g daily of white-flesh potatoes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plasma zeaxanthin
Time Frame: 28 days
Plasma concentration of zeaxanthin
28 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plasma lutein
Time Frame: 28 days
Plasma concentration of lutein
28 days
Skin carotenoid content
Time Frame: 28 days
Skin carotenoid content by reflection spectroscopy
28 days

Collaborators and Investigators

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

Sponsor

University of Florida

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)

May 28, 2026

Primary Completion (Estimated)

August 31, 2026

Study Completion (Estimated)

December 15, 2026

Study Registration Dates

First Submitted

May 18, 2026

First Submitted That Met QC Criteria

May 18, 2026

First Posted (Actual)

May 26, 2026

Study Record Updates

Last Update Posted (Actual)

June 11, 2026

Last Update Submitted That Met QC Criteria

June 9, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • IRB202600662

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

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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