Carotenoids in the Skin and Immune Aging

Carotenoids in the Skin and Immune Aging: a Pilot Observational Study

This study aims to examine the connection between the level of carotenoids in the skin and a number of immune related health parameters.

Study Overview

• Status: Recruiting
• Conditions: No Condition; Skin Carotenoids and Immune-aging

• Study Type: Observational
• Enrollment (Estimated): 40

Contacts and Locations

• Study Contact: Name: Xiaochen Zhong, BA; Phone Number: 408-816-0111; Email: xczhong@stanford.edu
• Study Contact Backup: Name: Po-Han Ho, MD; Email: pohanho@stanford.edu

Study Locations

• United States
  • California
    • Redwood City, California, United States, 94063
      • Recruiting
      • Stanford Health - General Dermatology Clinic
      • Principal Investigator: Anne Lynn S. Chang, MD

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Probability Sample

Study Population

Healthy individuals who are either between 18 to 30 years old or over 65 years old.

Description

Inclusion Criteria:

• Willing and able to provide written informed consent
• Age 18-30 years OR 65 years and older
• Healthy individuals without uncontrolled medical conditions (over the counter inhaled and topical steroids allowed)
• Fiitzpatrick I-VI (all skin types)

Exclusion Criteria:

• Pregnant or breastfeeding
• uncontrolled medical conditions
• Skin conditions on the upper extremity that would interfere with skin measurements of carotenoid levels such as active atopic dermatitis or psoriasis
• Concurrent use of medications that affect the immune system, within 4 weeks of enrollment (eg. prednisone, biologics, methotrexate, rapamycin, prescription topical steroids, prescription inhaled steroids, others)
• Unable to follow study protocol

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Young adult; Participants are 18 to 30 years old.
Older adult; Participants are over 65 years old.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skin carotenoid levels and skin aging features	We will assess the skin carotenoid levels' correlation with skin aging features, such as wrinkles, fine lines, and age spots.	one day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skin carotenoid levels and biomarkers of aging	We will assess the skin carotenoid levels' correlation with biomarkers associated with aging, such as C-reactive protein, telomere length, telomerase activity etc.	one day
Skin carotenoid levels and self-reported perception of health	We will assess the skin carotenoid levels' correlation with self reported scores on general health and health beliefs, incidence of respiratory, gut and skin allergy symptoms, and sleep quality.	2 weeks

Collaborators and Investigators

• Sponsor: Stanford University

Study record dates

Study Major Dates

• Study Start (Actual): October 9, 2025
• Primary Completion (Estimated): March 1, 2026
• Study Completion (Estimated): April 1, 2026

Study Registration Dates

• First Submitted: September 30, 2025
• First Submitted That Met QC Criteria: October 23, 2025
• First Posted (Estimated): October 28, 2025

Study Record Updates

• Last Update Posted (Actual): December 15, 2025
• Last Update Submitted That Met QC Criteria: December 11, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: 80982

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