Recruiting

Flavonoid Diets

Sponsor:

North Carolina Agriculture & Technical State University

Code:

NCT07767149

Conditions

Human Health

Flavonoids

Carbonyl Stress

Eligibility Criteria

Sex: All

Age: 25 - 70

Healthy Volunteers: Accepted

Interventions

High-Flavonoid Diet

Low-Flavonoid Diet

Study Details

Brief summary:

This randomized crossover study will compare low- and high-flavonoid diets in healthy adults to identify flavonoid-derived biomarkers in urine and plasma. Using targeted liquid chromatography-mass spectrometry (LC-MS) metabolomics, researchers will measure known and novel flavonoid metabolites and evaluate whether a higher flavonoid intake reduces carbonyl stress markers, including reactive carbonyl species (RCS) and advanced glycation end products (AGEs).

Conditions

Human Health

Flavonoids

Carbonyl Stress

Study ID

NCT07767149

Start date

Sep 2, 2026

Status verified date

Aug, 2026

Completion date

Dec 31, 2027

Anticipated

Primary completion date

Oct 15, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 25 - 70

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Age 25-70 years
  • BMI between 18 and 30
  • Have no known allergy to test food
  • Have no known allergies to green tea, apples, blueberries, soy milk, or pineapples
  • Be not engaging in high-intensity exercise
  • Having blood and urine clinical tests in the normal range.
  • Be not taking antibiotics for six months
  • Be not currently taking medication
  • No taking any prescription drugs
  • All flavonoid-enriched supplements should be avoided. The flavonoid-enriched supplements list includes soy isoflavones, Lipo-Flavonoid, Citrus Bioflavonoids Complex, Super Flavonoids, Super Antioxidants, Quercetin Supplement, Essential-C, flavonoids, and milk thistle. Also other flavonoid supplements, including but not limited to luteolin, Rutin, etc.
  • No drugs or supplements within three weeks of the experiment
  • Be nonsmoking
  • Have no alcoholic intoxication
  • No alcoholic addiction
  • < 3-4 drinks per week (less than 2 glasses (300 mL) per drink)
  • No alcohol within three weeks of the experiment
  • Have no extended exposure to industrial wastes

Exclusion Criteria:

  • Disease: gout, heart disease, peripheral vascular disease, degenerative kidney, degenerative liver, diabetes, GI disorders, or endocrine disorders
  • Cancer patients
  • Currently diagnosed cancer patients will be excluded.
  • Medication-free for >2 years could be considered.

Study Design

Enrollment

36 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: High-Flavonoid Diet, Then Low-Flavonoid Diet

All participants will first complete a 2-week low-flavonoid wash-in period. Participants in this sequence will then consume the high-flavonoid diet for 3 weeks, complete a 3-week low-flavonoid washout period, and then consume the low-flavonoid diet for 3 weeks.

experimental: Low-Flavonoid Diet Followed by High-Flavonoid Diet

All participants will first complete a 2-week low-flavonoid wash-in period. Participants in this sequence will then consume the low-flavonoid diet for 3 weeks, complete a 3-week low-flavonoid washout period, and then consume the high-flavonoid diet for 3 weeks.

Interventions

High-Flavonoid Diet

Participants will consume the high-flavonoid diet daily for 3 weeks. The diet includes 1 Red Delicious apple (approximately 160 g), freeze-dried whole blueberry powder (25 g), soy milk (240 mL), and decaffeinated Lipton green tea ( 2 g tea leaves), providing approximately 420 mg flavonoids per day.

Low-Flavonoid Diet

Participants will consume the low-flavonoid diet daily for 3 weeks. The diet includes 1/3 of Red Delicious, 107 g of pineapple; 8.3 g of blueberry powder plus 16.7 g of blueberry placebo powder; 80 mL of soy milk plus 160 mL of 2% low-fat milk; and 0.67 g tea leaves, providing approximately 140 mg flavonoids per day.

Primary outcome measure

  • Plasma and Urine Flavonoid Metabolites [ Time Frame: After the 3-week dietary intervention period. ]

Central Contacts and Locations

Central contacts

Shengmin Sang

704-250-5710ssang@ncat.edu

Locations

North Carolina Agriculture and Technical State University/ NRI Building

Recruiting

Kannapolis, North Carolina, United States, 28081

Contacts

Samantha Caroll

7047013024samantha_carroll@unc.edu

More Information

Sponsor

North Carolina Agriculture & Technical State University

Last update posted

Aug 24, 2026

Last verified

Aug, 2026

Keywords

  • flavonoids
  • Carbonyl stress
  • Advanced glycation end products (AGEs)
  • Metabolomics
  • Reactive carbonyl species (RCS)

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by North Carolina Agriculture & Technical State University on 2026-08-24.